NETWORK-1 SECURITY SOLUTIONS, INC.


                        Filed Pursuant to Rule 424(b)(3)
                           Registration No. 333-126013

                          PROSPECTUS SUPPLEMENT NO. 18
                     (To Prospectus dated December 22, 2005)


This is a prospectus supplement to our prospectus dated December 22, 2005 (the
"Prospectus") relating to the resale from time to time by selling stockholders
of up to 15,786,256 shares of our Common Stock, including shares issuable upon
exercise of outstanding warrants and options. On March 6, 2007, we filed with
the Securities and Exchange Commission a Current Report on Form 8-K. The text of
the Current Report on Form 8-K is attached to and a part of this supplement.

This prospectus supplement should be read in conjunction with the Prospectus and
the prior prospectus supplements, and may not be delivered or utilized without
the Prospectus and the prior prospectus supplements. This prospectus supplement
is qualified by reference to the Prospectus, except to the extent that the
information provided by this prospectus supplement supersedes the information
contained in the Prospectus.

The securities offered by the Prospectus involve a high degree of risk. You
should carefully consider the "Risk Factors" referenced on page 7 of the
Prospectus in determining whether to purchase the Common Stock.

The date of this prospectus supplement is March 6, 2007.

================================================================================

                                  UNITED STATES

                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549

                             -----------------------

                                    Form 8-K

                                 CURRENT REPORT

                     Pursuant to Section 13 or 15(d) of the

                         Securities Exchange Act of 1934

Date of Report (Date of earliest event reported):  February 28, 2007
                                                   -----------------

                       Network-1 Security Solutions, Inc.
--------------------------------------------------------------------------------
             (Exact name of registrant as specified in its charter)


          Delaware                       1-14896                  11-3027591
--------------------------------------------------------------------------------
(State or other jurisdiction          (Commission               (IRS Employer
    of incorporation)                 File Number)           Identification No.)


              445 Park Avenue, Suite 1028, New York, New York 10022
--------------------------------------------------------------------------------
                    (Address of principal executive offices)


Registrant's telephone number, including area code: (212) 829-5700


                                       N/A
--------------------------------------------------------------------------------
         (Former name or former address, if changed since last report.)

            Check the appropriate box below if the Form 8-K filing is intended
to simultaneously satisfy the filing obligation of the registrant under any of
the following provisions (SEE General Instruction A.2. below):

[ ] Written communications pursuant to Rule 425 under the Securities Act
    (17 CFR 230.425)

[ ] Soliciting material pursuant to Rule 14a-12 under the Exchange Act
    (17 CFR 240.14a-12)

[ ] Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange
    Act (17 CFR 240.14d-2(b))

[ ] Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange
    Act (17 CFR 240.13e-4(c))
================================================================================


ITEM 1.01 ENTRY INTO A MATERIAL DEFINITIVE AGREEMENT

            On February 28, 2007, the Registrant entered into an Employment
Agreement with Corey M. Horowitz pursuant to which Mr. Horowitz continued to
serve as the Registrant's Chairman and Chief Executive Officer for a two year
term at an annual base salary of $288,750 for the first year, increasing by 5%
for the second year. In connection with his employment agreement, Mr. Horowitz
was issued a five (5) year option to purchase 375,000 shares of the Registrant's
common stock at an exercise price of $1.46 per share, which vests in equal
quarterly amounts of 93,750 shares beginning March 31, 2007 through December 31,
2007, subject to acceleration upon a change of control. The Registrant also
agreed to issue to Mr. Horowitz on the one year anniversary date (February 28,
2008) an additional five (5) year option to purchase a minimum of 375,000 shares
of common stock at an exercise price equal to the closing price of the common
stock on the date of grant (provided, that, Mr. Horowitz's employment has not
been terminated "For Cause" (as defined) by the Registrant or without Good Cause
(as defined) by Mr. Horowitz), which option will similarly vest in equal
quarterly amounts over a one year period subject to acceleration upon a change
of control. In addition to the aforementioned option grants, the Registrant
extended for an additional three (3) years the expiration dates of all options
and warrants (an aggregate of 2,620,000 shares) expiring in the calendar year
2007 and 2008 owned by Mr. Horowitz and CMH Capital Management Corp. ("CMH"), an
affiliate.

            Under the terms of his Employment Agreement, Mr. Horowitz shall
receive bonus compensation in an amount equal to 5% of the Registrant's
royalties or other payments (before deduction of payments to third parties
including, but not limited to, legal fees and expenses and third party license
fees) received from licensing its patented technologies (including patents
currently owned and acquired or licensed on an exclusive basis during the period
in which Mr. Horowitz continues to serve as an executive officer of the
Registrant) (the "Royalty Bonus Compensation"). Mr. Horowitz shall also receive
bonus compensation, during the term of his employment, equal to 5% of the gross
proceeds from (i) the sale of any of the Registrant's patents or (ii) the
Registrant's merger with or into another corporation or entity. The Royalty
Bonus Compensation shall continue to be paid to Mr. Horowitz for the life of
each of the Registrant's patents with respect to licenses entered into with
third parties during Mr. Horowitz's term of employment or at anytime thereafter,
whether Mr. Horowitz is employed by the Registrant or not, provided, that, Mr.
Horowitz's employment has not been terminated by the Registrant "For Cause" (as
defined) or terminated by Mr. Horowitz without "Good Reason" (as defined). In
the event that Mr. Horowitz's employment is terminated by the Registrant "Other
Than For Cause" (as defined) or by Mr. Horowitz for "Good Reason" (as defined),
Mr. Horowitz shall be entitled to a lump sum severance payment of 12 months base
salary.

            In connection with his Employment Agreement, Mr. Horowitz has agreed
not to compete with the Registrant as follows: (i) during the term of the
agreement and for a period of 12 months thereafter if his employment is
terminated "Other Than For Cause" (as defined) provided he is paid his 12 month
base salary severance amount and (ii) for a period of two years from the
termination date, if terminated "For Cause" by the Registrant or "Without Good
Reason" by Mr. Horowitz. In accordance with his employment agreement, Mr.
Horowitz also has certain anti-dilution rights which provide that if at any time
during the period ended December 31, 2008, in the event that the Registrant
completes an offering of its common stock or any securities convertible or
exercisable into common stock (exclusive of securities issued upon exercise of

                                        2


outstanding options, warrants or other convertible securities), Mr. Horowitz
shall receive from the Registrant, at the same price as the securities issued in
the financing, such number of additional options to purchase common stock so
that he maintains the same derivative ownership percentage (21.47%) of the
Registrant based upon options and warrants owned by Mr. Horowitz and CMH
(exclusive of their ownership of shares of common stock) as of the time of
execution of the employment agreement; provided, that, the aforementioned
anti-dilution protection shall be afforded to Mr. Horowitz up to a maximum
future financing(s) of $2.5 million.

ITEM 9.01 FINANCIAL STATEMENTS ARE EXHIBITS

Exhibit Number       Description
--------------       -----------

10.1                 Employment Agreement, dated February 28, 2007, between
                     the Registrant and Corey M. Horowitz (including exhibits).























                                    SIGNATURE
                                    ---------


            Pursuant to the requirements of the Securities Exchange Act of 1934,
the Registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.


                       NETWORK-1 SECURITY SOLUTIONS, INC.



Dated: March 6, 2007              By: /s/ Corey M. Horowitz
                                      --------------------------------------
                                      Name: Corey M. Horowitz
                                      Title: Chairman & Chief Executive Officer




























                                        3


                                  EXHIBIT INDEX


Exhibit No.      Description
-----------      -----------

10.1             Employment Agreement, dated February 28, 2007, between the
                 Registrant and Corey M. Horowitz (including exhibits).

































                                        4

                                                                    EXHIBIT 10.1
                                                                    ------------


     EMPLOYMENT AGREEMENT dated February 28, 2007, between NETWORK-1 SECURITY
SOLUTIONS, INC., a Delaware corporation with its principal office located at 445
Park Avenue, Suite 1028, New York, New York 10022 (the "COMPANY"), and COREY M.
HOROWITZ residing at 1085 Park Avenue, New York, New York 10128 (the
"EXECUTIVE").

     The Company desires to enter into this Agreement in order to assure itself
of the continued services of Executive, and Executive desires to accept
continued employment with the Company, upon the terms and conditions hereinafter
set forth.

     NOW, THEREFORE, in consideration of the mutual covenants and obligations
hereinafter set forth, the parties agree as follows:

     SECTION 1. EMPLOYMENT. The Company hereby employs Executive, and Executive
hereby accepts employment by the Company, upon the terms and conditions
hereinafter set forth.

     SECTION 2. TERM. The employment of Executive hereunder shall be for a
period commencing on February 28, 2007 (the "COMMENCEMENT DATE") and ending on
the second anniversary of the Commencement Date (the "TERM") or such earlier
date upon which the employment of the Executive shall terminate in accordance
with the provisions hereof. The period commencing on the Commencement Date and
ending on the date of termination of Executive's employment hereunder shall be
called the "TERM OF EMPLOYMENT" for Executive, and the date on which the
Executive's employment hereunder shall terminate shall be called the
"TERMINATION DATE."

     SECTION 3. DUTIES. During the Term of Employment, Executive shall be
employed as Chairman and Chief Executive Officer of the Company and will act in
accordance with, and be subject to the policies and procedures as may be duly
adopted by the Board of Directors (the "BOARD") from time to time. Executive
shall perform such duties as are consistent therewith as the Board shall
designate. Executive will be responsible for the management and operations of
all aspects of the Company's business, including licensing of the Company's
patents, patent litigation oversight, patent acquisitions, and finance and
administration. Executive will also have direct responsibility, subject to Board
of Directors policies and resolutions as noted above, for all current and future
budget and staff, and profit and loss accountability for the Company in its
entirety. Executive shall use his best efforts to perform well and faithfully
the foregoing duties and responsibilities. In addition, Executive shall continue
to serve as Chairman of the Board and shall be nominated during the Term of
Employment on an annual basis as a director (subject to election by the
stockholders of the Company). On the Termination Date, if Executive is no longer
employed by the Company, he agrees to submit his resignation as a Board member
if requested by the Company. For purposes of this Agreement, so long as
Executive shall serve as a member of the Board, any references herein to
decisions or determinations to be made by the Board with respect to Executive
(including, without limitation, matters relating to compensation and
termination) shall be made by a majority of the then members of the Board
excluding Executive, who shall recuse himself and abstain from voting with
respect to any such matters.



     SECTION 4. TIME TO BE DEVOTED TO EMPLOYMENT. During the Term of Employment,
Executive shall devote such time, attention and energies to the business of the
Company as is necessary in the Board's reasonable judgment to perform his duties
and responsibilities as Chairman and Chief Executive Officer. It is understood
that Executive is not required to devote his full time and attention to the
business of the Company during the Term of Employment. Executive shall be
permitted to conduct other business activities so long as such activities do
not, in the reasonable judgment of the Board, conflict or interfere with the
duties of Executive hereunder.

     SECTION 5. COMPENSATION.

     (a) The Company shall pay to Executive an initial annual base salary of
$288,750 (the "BASE SALARY") during the first year of the Term of Employment,
payable in such installments (but not less often than monthly) as is generally
the policy of the Company with respect to its executive officers. The Base
Salary shall be increased by 5% on the one year anniversary of the Commencement
Date.

     (b) (i) In addition to the Base Salary set forth in paragraph 5(a) above,
during the Term of Employment, Executive shall receive incentive compensation
("BONUS COMPENSATION") in an amount equal to 5% of the Company's royalties or
other payments (before deduction of payments to third parties including, but not
limited to, legal fees and expenses and third party license fees) actually
received from licensing its patented technologies (including patents owned as of
the date hereof and acquired or licensed on an exclusive basis during the period
in which Executive continues to serve as an executive officer of the Company)
whether payable to the Company in the form of cash or securities (the "ROYALTY
BONUS COMPENSATION"). The Royalty Bonus Compensation shall be paid to Executive
within ten (10) days of the Company's actual receipt of the royalties. In
addition, during the Term of Employment, Executive shall also be entitled to
Bonus Compensation equal to 5% of the gross proceeds from (i) the sale of any of
the Company's patents, and (ii) the merger of the Company with or into another
corporation or entity with the result that the then existing stockholders of the
Company hold less than 50% of the combined voting power of the then outstanding
securities of the surviving entity in such transaction (the "Merger"); provided,
that, at the time of the Merger substantially all of the assets of the Company
(exclusive of cash) shall consist of the Company's patents and license
agreements with respect to the patents. For purposes hereof, gross proceeds from
a Merger shall include the total proceeds and other consideration paid or
received in connection with the Merger including cash, securities or other
assets. Such Bonus Compensation shall be paid within ten (10) days of the
closing of any such transaction.

     (c) The Royalty Bonus Compensation shall continue to be paid to Executive
for the life of each of the Company's patents (including patents owned as of the
date hereof and acquired or licensed on an exclusive basis during the period in
which Executive continues to serve as an executive officer of the Company) with
respect to licenses entered into by the Company with third parties during the
Term of Employment or at anytime thereafter whether Executive is employed by the
Company or not, provided, that, Executive's employment has not been terminated
by the Company for Cause as defined in Section 9(a) hereof or terminated by
Executive without Good Reason as defined in Section 10 hereof.

                                        2


     SECTION 6. EQUITY.

     (a) The Company recognizes that equity participation in the Company through
the grant of options is essential to induce Executive to agree to continue to
provide the services pursuant to this Agreement. Accordingly, (i) on the
Commencement Date the Company shall grant to Executive a five (5) year stock
option to purchase 375,000 shares of the Company's Common Stock and (ii) on the
one year anniversary of the Commencement Date the Company shall grant to
Executive a five (5) year stock option to purchase a minimum of 375,000 shares
of the Company's Common Stock, provided, that, Executive's employment has not
been terminated by the Company for cause as defined in Section 9(a) hereof or
terminated by Executive without good reason as defined in Section 10 hereof
(collectively, the "NEW OPTIONS"). The exercise price per share of the New
Options shall equal the closing price of the Company's common stock on the date
of grant of each New Options (the Commencement Date shall be the date of grant
for the New Options to purchase 375,000 shares issued on the date hereof). The
New Options shall each vest in equal quarterly amounts over a one year period
beginning March 31, 2007 and March 31, 2008, respectively, subject to
accelerated vesting in the event of a change of control (as defined in the form
of New Option). The form of New Options is attached as EXHIBIT A hereto. In
addition to grants of the New Options, the Company agrees on the Commencement
Date to extend for an additional 3 years the expiration dates of all options and
warrants expiring in calendar year 2007 and 2008 owned by Executive and CMH
Capital Management Corp. ("CMH"), an affiliated entity of Executive (the
"EXTENDED OPTIONS AND WARRANTS"). A list of the Extended Options and Warrants is
set forth on EXHIBIT B hereto. Following the issuance of the New Options
(including the New Option in the minimum amount of 375,000 shares to be issued
on the one year anniversary of the Commencement Date), when aggregated with the
prior options and warrants owned by Executive and CMH (including the Extended
Options and Warrants), Executive's ownership in the Company represented by all
options and warrants owned by him and CMH (exclusive of ownership of common
stock) as of the date hereof will be equal to 21.47% of the Company's
outstanding securities on a fully diluted basis (assuming the exercise and
conversion of all outstanding options, warrants and convertible securities (the
"DERIVATIVE OWNERSHIP PERCENTAGE"). A list of all options and warrants owned by
Executive and CMH including the New Options and the Extended Options and
Warrants issued pursuant to this Section 6(a) together with a calculation of the
Derivative Ownership Percentage, is attached as EXHIBIT B. The Company agrees to
file an amendment to its Registration Statement on Form S-8, within 30 days as
so directed by Executive, to register the shares underlying the New Options
issued on the date hereof pursuant to this Section 6(a) hereof.

     (b) At anytime during the period ended December 31, 2008, in the event that
the Company completes a financing (either a single transaction or series of
transactions) consisting of the issuance of common stock or any other securities
convertible or exercisable into common stock, Executive shall receive (at the
closing of such financing) from the Company, at the same price as the securities
issued in the financing, such number of additional options to purchase Common
Stock so that Executive maintains his same Derivative Ownership Percentage as of
the date hereof; provided, that, the provisions of this Section 6(b) shall
provide anti-dilution protection up to one or more maximum financing(s)
aggregating $2.5 million. Any such additional options to be issued to Executive
shall immediately vest on the date of grant and shall contain substantially the
same provisions (exclusive of the vesting provisions) as the New Options issued
pursuant to Section 6(a) hereof.

                                        3


     SECTION 7. BUSINESS EXPENSES; BENEFITS.

     (a) The Company shall reimburse Executive, in accordance with the practice
from time to time for executive officers of the Company, for all reasonable and
necessary expenses and other disbursements incurred by Executive for or on
behalf of the Company in the performance of Executive's duties hereunder.
Executive shall provide such appropriate documentation of expenses and
disbursements as may from time to time be required by the Company.

     (b) During the Term of Employment, Executive shall be entitled to four (4)
weeks vacation per year.

     (c) During the Term of Employment, Executive shall be entitled to
participate in the group health, life, dental and disability insurance benefits,
and retirement plan benefits made available from time to time for its executive
officers and other employees.

     SECTION 8. INVOLUNTARY TERMINATION.

     (a) If Executive is incapacitated or disabled to the extent he cannot
perform his duties under this Agreement for twelve (12) consecutive weeks, or
for a cumulative total of six (6) months in any calendar year (such condition
being hereinafter referred to as a "DISABILITY"), the Term of Employment and
employment of the Executive under this Agreement shall cease (such termination,
as well as a termination under Section 8(b), being hereinafter referred to as an
"INVOLUNTARY TERMINATION") and Executive shall be entitled to receive the
benefits payable under any disability policy maintained by the Company on his
behalf and in accordance with Section 11(b) hereof.

     (b) If Executive dies during the Term of Employment, the Term of Employment
and Executive's employment hereunder shall cease as of the date of the
Executive's death and Executive shall be entitled to receive the benefits
payable in accordance with Section 11 (b) hereof.

     SECTION 9. TERMINATION BY THE COMPANY. ]

     (a) TERMINATION FOR CAUSE. The Company may terminate the Term of Employment
and the employment of the Executive hereunder at any time for Cause (as
hereinafter defined) (such termination being referred to herein as a
"TERMINATION FOR CAUSE") by giving Executive written notice of such termination,
effective immediately upon the giving of such notice to Executive. As used in
this Agreement, "CAUSE" means the Executive's (a) commission of an act (i)
constituting a felony or (ii) involving fraud, moral turpitude, theft or
dishonesty which is not a felony and which materially adversely affects the
Company or could reasonably be expected to materially adversely affect the
Company, (b) repeated failure to be reasonably available to perform his duties
(other than as a result of illness or incapacity), which, if curable, shall not
have been cured within 30 days of written notice thereof from the Company, (c)
repeated failure to follow the lawful directions of the Board, which, if
curable, shall not have been cured within 30 days of written notice thereof from
the Company, or (d) material breach of the terms and provisions of this
Agreement or any agreement with the Company which, if curable, shall not have
been cured within 30 days of written notice thereof from the Company.

     (b) TERMINATION OTHER THAN FOR CAUSE. The Company may terminate the Term of
Employment and the employment of Executive hereunder at any time other than for
Cause as

                                        4


defined in Section 9(a) above (such termination shall be defined as a
"TERMINATION OTHER THAN FOR CAUSE") by giving Executive written notice of such
termination, which notice shall be effective thirty (30) days after the giving
of such notice or such later date set forth therein.

     SECTION 10. TERMINATION BY EXECUTIVE. If at any time during the Term of
Employment, Executive elects to terminate Executive's employment with the
Company (other than for "GOOD REASON", as defined below), then the Company's
obligations to Executive under this Agreement shall be as set forth in Section
11(e) hereof and such termination by Executive shall constitute a breach of this
Agreement. If Executive elects to terminate Executive's employment with the
Company for Good Reason, then the Company shall pay Executive the amounts set
forth in Section 11(d) hereof. For the purpose of this Section, "Good Reason"
means (i) any material diminution of duties inconsistent with Executive's title,
authority, duties and responsibilities as Chairman and Chief Executive Officer;
(ii) any reduction of or failure to pay Executive compensation provided for
herein, which non-payment continues for a period of thirty (30) days following
written notice to the Company by Executive of such non-payment, except to the
extent Executive consents in writing to any reduction, deferral or waiver of
compensation; (iii) any relocation of the principal location of Executive's
employment more than 75 miles from the Corporation's current headquarters in New
York, New York without Executive's prior written consent; or (iv) any material
violation by the Company of its obligations under this Agreement that is not
cured (if curable) within thirty (30) days after receipt of notice thereof.

     SECTION 11. EFFECT OF TERMINATION.

     (a) Upon the termination of the Term of Employment and Executive's
employment hereunder due to a Termination for Cause (as defined in Section 9(a)
above), Executive shall not have any further rights or claims against the
Company under this Agreement, except the right to receive (i) the unpaid
portion, if any, of (a) the Base Salary provided for in Section 5(a), computed
on a pro rata basis through the Termination Date and (b) Bonus Compensation
(including the Royalty Bonus Compensation) provided for in Section 5(b) earned
prior to the Termination Date, (ii) any unpaid accrued benefits of Executive,
(iii) reimbursement for any expenses for which Executive shall not have been
reimbursed as provided in Section 7(a), and (iv) Executive's rights under the
vested portion of any options or warrants issued to Executive and CMH by the
Company including the New Options issued in accordance with Section 6(a) hereof,
(collectively, the "AGGREGATE DERIVATIVE SECURITIES").

     (b) Upon the termination of Executive's employment hereunder due to an
Involuntary Termination, neither Executive nor his beneficiary or estate shall
have any further rights or claims against the Company under this Agreement
except the right to receive (i) the amounts set forth in Section 11(a), (ii)
Bonus Compensation in accordance with Section 5(c), and (iii) the accelerated
vesting of all of the Aggregate Derivative Securities that would have vested
twelve (12) months from the date of Involuntary Termination.

     (c) Upon the termination of Executive's employment upon a Termination Other
Than for Cause (as defined in Section 9(b) above), neither Executive nor his
beneficiary nor his estate shall have any rights or claims against the Company
except to receive (i) the amounts set forth in 11(b), and (ii) a severance equal
to twelve (12) months Base Salary as in effect at the time of the Termination
Other Than for Cause, such sum to be paid in a lump sum payment upon
termination.

                                        5


     (d) Upon the termination of Executive's employment by Executive for Good
Reason (as defined in Section 10 above), neither Executive nor his beneficiary
or estate shall have any further rights or claims against the Company under this
Agreement, except the right to receive the amounts set forth in Section 11(c).

     (e) Upon the termination of Executive's employment by Executive (other than
for Good Reason), neither Executive nor his beneficiary or estate shall have any
further rights or claims against the Company under this Agreement, except the
right to receive the amounts set forth in Section 11(a).

     SECTION 12. INSURANCE. The Company may, for its own benefit, in its sole
discretion, and at its sole cost and expense, maintain "key-man" life and
disability insurance policies covering Executive. Executive will cooperate with
the Company and provide such information or other assistance as the Company may
reasonably request in connection with the Company's obtaining and maintaining
such policies.

     SECTION 13. DISCLOSURE OF INFORMATION. Executive will not, either during
the Term of Employment or at any time thereafter, divulge, publish, communicate,
furnish or make accessible to anyone (other than in furtherance of the purposes
of the Company) any knowledge or information with respect to the Company's
confidential, secret or proprietary information or assets, or with respect to
any other confidential, secret or proprietary aspects of the business,
activities or intellectual property of the Company including, without
limitation, (a) patents and related intellectual property, terms of patent
acquisition contracts or licensing arrangements, or other technical data
pertaining to the Company's patents and intellectual property (whether or not
subject to patent, trademark or copyright protection) or (b) business strategies
and plans including, but not limited to, litigation strategies and potential
patent acquisitions; except as such items set forth in clauses (a) and (b) above
may already be in the public domain through no fault of Executive (all of the
foregoing items set forth in clauses (a) and (b) being referred to herein
collectively as "CONFIDENTIAL PROPERTY") or except as otherwise required by law.
In the event that Executive becomes legally compelled to disclose any
Confidential Property, Executive shall advise the Company as soon as practicable
so that the Company may seek a protective order or other appropriate remedy. In
addition, Executive agrees to cooperate in the Company's effort, at the
Company's expense, to obtain a protective order or other appropriate remedy.
Upon the termination of the Term of Employment, Executive shall return to the
Company all property (including Confidential Property) of the Company (or any
subsidiary or affiliate thereof) then in the possession of Executive and all
books, records, computer tapes or discs and all other material containing
non-public information concerning the business or affairs of the Company or any
subsidiary or affiliate thereof.

     SECTION 14. RIGHT TO INVENTIONS. (a) Executive shall promptly disclose,
grant and assign to the Company for its sole use and benefit any and all marks,
designs, logos, inventions, improvements, technical information and suggestions
relating in any way to the business conducted by the Company, which he may
develop or which may be acquired by Executive during the Term of Employment
(whether or not during usual working hours), together with all trademarks,
patent applications, letters, patent, copyrights and reissues thereof that may
at any time be granted for or upon any such mark, design, logo, invention,
improvement or technical information (collectively, "INVENTIONS"). In connection
therewith, Executive shall (at the Company's sole cost and expense)

                                        6


take all actions reasonably necessary or desirable to assign and/or confirm the
assignment of any Invention to the Company.

     (b) To the extent any of the rights, title and interest in and to
Inventions cannot be assigned by Executive to the Company, Executive hereby
grants to the Company an exclusive, royalty-free, transferable, irrevocable,
worldwide license (with rights to sublicense through multiple tiers of
sublicensees) to practice such non-assignable rights, title and interest. To the
extent any of the rights, title and interest in and to Inventions can be neither
assigned nor licensed by Executive to the Company, Executive hereby irrevocably
waives and agrees never to assert such non-assignable and non-licensable rights,
title and interest against the Company or any of the Company's successors in
interest to such non-assignable and non-licensable rights. Executive hereby
grants to the Company or the Company's designees a royalty free, irrevocable,
worldwide license (with rights to sublicense through multiple tiers of
sublicensees) to practice all applicable patent, copyright, moral right, mask
work, trade secret and other intellectual property rights relating to any prior
inventions which Executive incorporates, or permits to be incorporated, in any
Inventions. Notwithstanding the foregoing, Executive agrees that he will not
incorporate, or permit to be incorporated, any prior inventions of Executive in
any Inventions without the Company's prior written consent.

     SECTION 15. FUTURE INNOVATIONS. Executive recognizes that Inventions or
Confidential Property relating to his activities while working for the Company
and conceived, reduced to practice, created, derived, developed, or made by
Executive, alone or with others, within three (3) months after termination of
his employment may have been conceived, reduced to practice, created, derived,
developed, or made, as applicable, in significant part while employed by the
Company. Accordingly, Executive agrees that such Inventions or Confidential
Property shall be presumed to have been conceived, reduced to practice, created,
derived, developed, or made, as applicable, during his employment with the
Company and are to be promptly assigned to the Company unless and until
Executive has established the contrary by written evidence satisfying the clear
and convincing standard of proof.

     SECTION 16. COOPERATION IN PERFECTING RIGHTS TO PROPRIETARY INFORMATION AND
                 INNOVATIONS.

     (a) Executive agrees to perform, during and after his employment, all acts
deemed necessary or desirable by the Company to permit and assist the Company
(during any period after Executive's termination of employment with the Company,
subject to Executive's obligations to his then employer, if any), at the
Company's expense, in obtaining and enforcing the full benefits, enjoyment,
rights and title throughout the world in the Inventions or Confidential Property
assigned or licensed to, or whose rights are irrevocably waived and shall not be
asserted against, the Company under this Agreement. Such acts may include, but
are not limited to, execution of documents and assistance or cooperation (i) in
the filing, prosecution, registration, and memorialization of assignment of any
applicable patents, copyrights, mask work, or other applications, (ii) in the
enforcement of any applicable patents, copyrights, mask work, moral rights,
trade secrets, or other proprietary rights, and (iii) in other legal proceedings
related to the Inventions or Confidential Property.

     (b) In the event that the Company is unable (after reasonable efforts) to
secure Executive's signature to any document required to file, prosecute,
register, or memorialize the

                                        7


assignment of any patent, copyright, mask work or other applications or to
enforce any patent, copyright, mask work, moral right, trade secret or other
proprietary right under any Inventions (including derivative works,
improvements, renewals, extensions, continuations, divisionals, continuations in
part, continuing patent applications, reissues, and reexaminations thereof),
Executive hereby irrevocably designates and appoints the Company and the
Company's duly authorized officers and agents as his agents and
attorneys-in-fact to act for and on his behalf and instead of him, (i) to
execute, file, prosecute, register and memorialize the assignment of any such
application, (ii) to execute and file any documentation required for such
enforcement, and (iii) to do all other lawfully permitted acts to further the
filing, prosecution, registration, memorialization of assignment, issuance, and
enforcement of patents, copyrights, mask works, moral rights, trade secrets or
other rights under Inventions, all with the same legal force and effect as if
executed by Executive.

     SECTION 17. RESTRICTIVE COVENANT.

     (a) The Company is in the business of pursuing licensing opportunities
related to its patented technologies with third parties who the Company believes
are infringing its patents and intellectual property or who may require a
license for future products, and which business strategy has required, and may
require in the future, the Company to commence patent infringement lawsuits
against third parties (the "BUSINESS"). Executive acknowledges and recognizes
that the Business may be conducted throughout the world, and Executive further
acknowledges and recognizes the highly competitive nature of the Company's
Business. Accordingly, in consideration of the premises contained herein, the
consideration to be received hereunder and the New Options and Extended Options
and Warrants granted to Executive in accordance with Section 6 hereof, Executive
shall not, during the Non-Competition Period (as defined below): (i) directly or
indirectly engage, whether or not such engagement shall be as a partner,
stockholder, officer, director, affiliate or other participant, in any
Competitive Business (as defined below), or represent in any way any Competitive
Business, whether or not such engagement or representation shall be for profit,
(ii) interfere with, disrupt or attempt to disrupt the relationship, contractual
or otherwise, between the Company and any other person or entity, including,
without limitation, any licensee, customer, supplier, employee or consultant of
the Company, (iii) induce any employee or consultant of the Company to terminate
his employment or consultancy with the Company or to engage in any Competitive
Business in any manner described in the foregoing clause (i), or (iv)
affirmatively assist or induce any other person or entity to engage in any
Competitive Business in any manner described in the foregoing clause (i).
Anything contained in this Section 17 to the contrary notwithstanding, an
investment by Executive in any publicly traded company in which Executive and
his affiliates exercise no operational or strategic control and which
constitutes less than 5% of the outstanding shares of such entity shall not
constitute a breach of this Section 17.

     (b) As used herein, "Non-Competition Period" shall mean the period
commencing on the date hereof and terminating on the Termination Date; provided,
however, that (i) if the Term of Employment shall have been Terminated Other
Than For Cause by the Company pursuant to Section 9(b) hereof, then the
"Non-Competition Period" shall mean the period commencing on the date hereof and
ending twelve (12) months thereafter; provided Executive is paid the severance
equal to twelve (12) months Base Salary as provided in Section 11(c) hereof and
(ii) if the Term of Employment shall have been terminated for Cause by the
Company pursuant to Section 9(a) hereof or without Good Reason pursuant to
Section 10 hereof, then the "Non-Competition Period" shall mean the period
commencing on the date hereof and ending on the second anniversary of the

                                        8


Termination Date. "Competitive Business" shall mean any entity throughout the
world (i) utilizing or pursuing licensing opportunities related to patented
technologies competitive with the Company's patents, (ii) any entity in which
the Company has acquired patents from and/or entered into a license agreement or
similar arrangement relating to the Company's patented technologies and (iii)
any entity engaged in a business competitive with any business then engaged in
by the Company; provided, that, Executive may render services for (either as an
employee or independent consultant) for any entity under (i), (ii), or (iii)
above in this Section 17(b) so long as his duties and responsibilities for
entities have nothing to do with any business directly or indirectly related to
the Company's patents.

     (c) Executive understands that the foregoing restrictions may limit his
ability to earn a livelihood in a business similar to the business of the
Company, but he nevertheless believes that he has received and will receive
sufficient consideration and other benefits as an employee of the Company and as
otherwise provided hereunder and pursuant to other agreements between the
Company and Executive to justify clearly such restrictions which, in any event
(given his education, skills and ability), Executive does not believe would
prevent him from earning a living.

     SECTION 18. ENFORCEMENT; SEVERABILITY; ETC. It is the desire and intent of
the parties that the provisions of this Agreement shall be enforced to the
fullest extent permissible under the laws and public policies applied in each
jurisdiction in which enforcement is sought. Accordingly, if any particular
provision of this Agreement shall be adjudicated to be invalid or unenforceable,
such provision shall be deemed amended to (a) delete therefrom the portion thus
adjudicated to be invalid or unenforceable, such deletion to apply only with
respect to the operation of such provision in the particular jurisdiction in
which such adjudication is made or (b) otherwise to render it enforceable in
such jurisdiction.

     SECTION 19. REMEDIES. Executive acknowledges and understands that the
provisions of this Agreement are of a special and unique nature, the loss of
which cannot be adequately compensated for in damages by an action at law, and
that the breach or threatened breach of the provisions of this Agreement would
cause the Company irreparable harm. In the event of a breach or threatened
breach by Executive of the provisions of this Agreement, the Company shall be
entitled to an injunction restraining him from such breach. Nothing contained in
this Agreement shall be construed as prohibiting the Company from or limiting
the Company in pursuing any other remedies available for any breach or
threatened breach of this Agreement.

     SECTION 20. NOTICES. All notices, claims, certificates, requests, demands
and other communications hereunder shall be in writing and shall be deemed to
have been duly given and delivered if personally delivered or if sent by a
nationally-recognized overnight courier, by telecopy, or by registered or
certified mail, return receipt requested and postage prepaid, addressed as
follows:

if to the Company, to:              Network-1 Security Solutions, Inc.
                                    445 Park Avenue, Suite 1028
                                    New York, New York 10022
                                    Telecopier: 917-322-2105
                                    Telephone: (212) 829-5700

                                        9


with copies to:                     Eiseman Levine Lehrhaupt & Kakoyiannis, P.C.
                                    805 Third Avenue
                                    New York, New York 10022
                                    Telecopier: (212) 355-4608
                                    Telephone: (212) 752-1000
                                    Attention: Sam Schwartz, Esq.

if to Executive, to:                Corey M. Horowitz
                                    1085 Park Avenue
                                    New York, New York
                                    Telephone: (212) 831-9333

or to such other address as the party to whom notice is to be given may have
furnished to the other party or parties in writing in accordance herewith. Any
such notice or communication shall be deemed to have been received (a) in the
case of personal delivery, on the date of such delivery, (b) in the case of
nationally-recognized overnight courier, on the next business day after the date
when sent, (c) in the case of telecopy transmission, when received, and (d) in
the case of mailing, on the third business day following that on which the piece
of mail containing such communication is posted.

     SECTION 21. BINDING AGREEMENT; BENEFIT. The provisions of this Agreement
will be binding upon, and will inure to the benefit of, the respective heirs,
legal representatives, successors and assigns of the parties.

     SECTION 22. GOVERNING LAW. This Agreement will be governed by, construed
and enforced in accordance with, the laws of the State of New York without
giving effect to principles of conflicts of laws.

     SECTION 23. WAIVER OF BREACH. The waiver by either party of a breach of any
provision of this Agreement must be in writing and shall not operate or be
construed as a waiver of any other breach.

SECTION 24. ENTIRE AGREEMENT; AMENDMENTS. This Agreement contains the entire
agreement between the parties with respect to the subject matter hereof and
supersedes all prior agreements or understandings, whether written or oral,
between the parties with respect thereto. This Agreement may be amended only by
an agreement in writing signed by the parties.

     SECTION 25. SURVIVAL OF PROVISIONS. Neither the termination of this
Agreement, nor of Executive's employment hereunder, shall terminate or affect in
any manner any provisions of this Agreement that is intended by its terms to
survive such termination, including, without limitation, the provisions of
Sections 11, 13, 14, 15, 16 and 17.

     SECTION 26. HEADINGS. The section headings contained in this Agreement are
for reference purposes only and shall not affect in any way the meaning or
interpretation of this Agreement.

                                       10


     SECTION 27. ASSIGNMENT. This Agreement is personal in its nature and the
parties shall not, without the consent of the other, assign or transfer this
Agreement or any rights or obligations hereunder.

     SECTION 28. GENDER. Any reference to the masculine gender shall be deemed
to include the feminine and neuter genders unless the context otherwise
requires.

     SECTION 29. COUNTERPARTS. This Agreement may be executed in counterparts,
and each such counterpart shall be deemed to be an original instrument, but all
such counterparts together shall constitute but one agreement.

     IN WITNESS WHEREOF, the parties hereto have executed and delivered this
Employment Agreement as of the date first written above.

                                 NETWORK-1 SECURITY SOLUTIONS, INC.


                                 By: /s/David C. Kahn
                                     ---------------------------------------
                                     David C. Kahn, Chief Financial Officer



                                     EXECUTIVE


                                     /s/ Corey M. Horowitz
                                     ---------------------------------------
                                     Corey M. Horowitz



                                       11


                                    EXHIBIT A

                             STOCK OPTION AGREEMENT

     STOCK OPTION AGREEMENT, dated as of February 28, 2007, (this " Stock Option
Agreement") by and between Network-1 Security Solutions, Inc., a Delaware
corporation with principal executive offices a 445 Park Avenue, Suite 1028, New
York, New York 10022 ("Network-1"), and Corey M. Horowitz, residing at 1085 Park
Avenue, New York, New York 10128 ("Horowitz").

     WHEREAS, in accordance with Section 6(a) of the Employment Agreement, dated
February 28, 2007, between the Company and Horowitz (the "Employment
Agreement"), the Company agreed, to issue to Horowitz an option to purchase
375,000 shares of the Company's Common Stock, upon the terms and conditions set
forth herein; and

     NOW THEREFORE, in consideration of the premises and of the mutual
covenants, representations, warranties and agreements contained herein and in
the Employment Agreement, and intending to be legally bound hereby, the parties
hereto agree as follows:

     SECTION 1. Grant of Option.

     Network-1 hereby grants to Horowitz an option (the "Option") to purchase,
out of its authorized but unissued shares of Common Stock, 375,000 shares of
Common Stock (the shares of Common Stock purchased or purchasable pursuant to
the Option, subject to adjustment as set forth herein, being referred to as the
"Option Shares"), at an exercise price per share equal to $1.46 (such exercise
price, subject to adjustment as set forth herein, being referred to as the
"Exercise Price", or in the aggregate, the "Aggregate Exercise Price"). Horowitz
and/or his transferees or assigns are hereinafter referred to as "Holder".

     SECTION 2. Term and Exercise of Option.

     (a) The Option granted hereby shall vest on a calendar quarterly basis in
equal shares of 93,750 beginning March 31, 2007 through December 31, 2007. This
Option may be exercised in whole or in part as to vested shares at any time
through February 28, 2012 (the "Expiration Date") by Holder's presentation of
this Option, with the Exercise Form attached hereto duly executed, at
Network-1's office (or such office or agent of Network-1 as it may designate in
writing to the Holder hereof by notice pursuant to Section 13 hereof),
specifying the number of Option Shares as to which the Option is being
exercised.

     (b) In the event of (i) a "change of control" (as hereinafter defined) of
Network-1 at any time prior to the Expiration Date, this Option may, from and
after such date, and notwithstanding paragraph 2(a) hereof, be exercised for up
to 100% of the total number of shares then subject to the Option minus the
number of shares previously purchased upon exercise of the Option (as adjusted
for any changes in the outstanding Common Stock by reason of a stock dividend,
stock split, combination of shares, recapitalization, merger, consolidation,
transfer of assets, reorganization, conversion or what the Compensation
Committee or the Board of Directors deems in its sole discretion to be similar
circumstances).



     (c) A "Change of Control" shall be deemed to have occurred upon the
happening of any of the following events: (i) the shareholders of Network-1
approve a merger of consolidation of Network-1 with any other entity, other than
a merger or consolidation which would result in the voting securities of
Network-1 outstanding immediately prior thereto continuing to represent more
than fifty percent (50%) of the total voting power represented by the voting
securities of Network-1 or such surviving entity outstanding immediately after
such merger or consolidation, or the shareholders of Network-1 approve a plan of
complete liquidation of Network-1 or consummate the sale or disposition by
Network-1 of all or substantially all of Network-1's assets (other than to a
subsidiary or subsidiaries) or (ii) any other event deemed to constitute a
"Change of Control" by the Compensation Committee or the Board of Directors of
Network-1.

     SECTION 3. Issuance of Option Shares; Cashless Exercise

     (a) Upon surrender of the Option and payment of the Exercise Price as
provided herein, Network-1 shall issue and deliver with all reasonable dispatch
the certificate(s) for the Option Shares to or upon the written order of the
Holder and in such name or names as the Holder may designate. Such
certificate(s) shall represent the number of Option Shares issuable upon the
exercise of the Option, together with a cash amount in respect of any fraction
of a share otherwise issuable upon such exercise.

     (b) In lieu of paying the Aggregate Exercise Price in cash and/or upon
exercise of the Option, the Holder may elect a "cashless exercise" in which
event the Holder will receive upon exercise a reduced number of Option Shares
equal to (i) the number of Option Shares that would be issuable pursuant to the
Option upon payment of the Aggregate Exercise Price minus (ii) the number of
Option Shares that have an aggregate Market Price (as defined below) equal to
the Aggregate Exercise Price.

     (c) Unless otherwise provided herein, for purposes of any computations made
in this Stock Option Agreement, "Market Price" per share of shares of Common
Stock on any date shall be: (i) if the shares of Common Stock are listed or
admitted for trading on any national securities exchange, the last reported
sales price as reported on such national securities exchange; (ii) if the shares
of Common Stock are not listed or admitted for trading on any national
securities exchange, the average of the last reported closing bid and asked
quotation for the shares of Common Stock as reported on the Nasdaq Stock
Market's National Market ("NNM") or Nasdaq Stock Market's Small Cap Market
("NSM") or a comparable service if NNM or NSM are not reporting such
information; (iii) if the shares of Common Stock are not listed or admitted for
trading on any national securities exchange, NNM or NSM or a comparable system,
the average of the last reported bid and asked quotation for the shares of
Common Stock as quoted by a market maker in the shares of Common Stock (or if
there is more than one market maker, the bid and asked quotation shall be
obtained from two market makers and the average of the lowest bid and highest
asked quotation shall be the "Market Price"); or (iv) if the shares of Common
Stock are not listed or admitted for trading on any national securities exchange
or NNM or quoted by NSM and there is no market maker in the shares of Common
Stock, the fair market value of such shares as determined in good faith by the
Board of Directors of Network-1.

     (d) Certificates representing the Option Shares shall be deemed to have
been issued and the person so designated to be named therein shall be deemed to
have become a holder of record of such Option Shares as of the date of the
surrender of the Option and payment of the

                                        2


Aggregate Exercise Price as provided herein; notwithstanding that the transfer
books for the Option Shares or other classes of stock purchasable upon the
exercise of the Option shall then be closed or the certificate(s) for the Option
Shares in respect of which the Option is then exercised shall not then have been
actually delivered to the Holder. As soon as practicable after each such
exercise of the Option, Network-1 shall issue and deliver the certificate(s) for
the Option Shares issuable upon such exercise, registered as requested. In the
event that only a portion of the Option is exercised at any time prior to the
close of business on the Expiration Date, a new option shall be issued to the
Holder for the remaining number of Option Shares purchasable pursuant hereto.
Network-1 shall cancel the Option when they are surrendered upon exercise.

     (e) Prior to due presentment for registration of transfer of the Option,
Network-1 shall deem and treat the Holder as the absolute owner of the Option
(notwithstanding any notation of ownership or other writing on this Option
Agreement made by anyone other than Network-1) for the purpose of any exercise
hereof or any distribution to the Holder and for all other purposes, and
Network-1 shall not be affected by any notice to the contrary.

     SECTION 4. Lost, Stolen, or Mutilated Option

     In case this Option shall be mutilated, lost, stolen or destroyed,
Network-1 shall issue and deliver, in exchange and substitution for and upon
cancellation of the mutilated Option, or in lieu of and substitution for the
Option lost, stolen or destroyed, a new Option of like tenor and representing an
equivalent number of Option Shares purchasable upon exercise, but only upon
receipt of evidence reasonably satisfactory to Network-1 of such mutilation,
loss, theft or destruction of such Option and reasonable indemnity, if
requested, also reasonably satisfactory to Network-1. No bond or other security
shall be required from Holder in connection with the replacement by Network-1 of
a lost, stolen or mutilated warrant certificate.

     SECTION 5. Rights Upon Expiration

     Unless the Option is surrendered and payment made for the Option Shares as
herein provided before the close of business on the Expiration Date, this Option
will become wholly void and all rights evidenced hereby will terminate after
such time.

     SECTION 6. Exchange of Option

     This Option may be exchanged for a number of Options of the same tenor as
this Option for the purchase in the aggregate of the same number of Option
Shares of Network-1 as are purchasable upon the exercise of this Option, upon
surrender hereof at the office of Network-1 with written instructions as to the
denominations of the Options to be issued in exchange.

     SECTION 7. Adjustment for Certain Events

     (a) In case Network-1 shall at any time after the date hereof (i) declare a
dividend on its shares of Common Stock payable in shares of Network-1's capital
stock (whether in shares of Common Stock or of capital stock of any other
class), (ii) subdivide its outstanding shares of Common Stock, (iii) reverse
split its outstanding shares of Common Stock into a smaller number of shares, or
(iv) issue any shares of Network-1's capital stock in a reclassification of
shares of Common Stock (including any such reclassification in connection with a
consolidation or merger in which Network-1 is the continuing corporation), then,
in each case, the Exercise Price in effect at

                                        3


the time of the record date for such dividend or of the effective date of such
subdivision, reverse split or reclassification, and/or the number and kind of
shares of capital stock issuable upon exercise of the Option on such date, shall
be proportionately adjusted so that the holder of the Option exercised after
such time shall be entitled to receive the aggregate number and kind of
securities which, if such Option had been exercised immediately prior to such
date, such Holder would have owned upon such exercise and been entitled to
receive by virtue of such dividend, subdivision, reverse split or
reclassification. Such adjustment shall be made successively whenever any event
listed above shall occur.

     (b) In case Network-1 shall fix a record date for the making of a
distribution to all holders Common Stock (including any such distribution made
in connection with a consolidation or merger in which Network-1 is the
continuing corporation) of evidences of indebtedness or assets (other than cash
dividends or cash distributions payable out of earnings, consolidated earnings,
if Network-1 shall have one or more subsidiaries, or earned surplus, or
dividends payable in Common Stock) or rights, options or warrants to subscribe
for or purchase Common Stock, then, in each case, the Exercise Price to be in
effect after such record date shall be determined by multiplying the Exercise
Price in effect immediately prior to such record date by a fraction, of which
the numerator shall be the current Market Price for one share of Common Stock on
such record date less the fair market value of the portion of the assets or
evidences of indebtedness so to be distributed or of such subscription rights,
options or warrants applicable to one share of Common Stock, and of which the
denominator shall be the current Market Price for one share of Common Stock. In
the event that Network-1 and the Holder cannot agree as to such fair market
value, such determination of fair market value shall be made by an appraiser who
shall be mutually selected by Network-1 and the Holder, and the reasonable costs
of such appraiser shall be borne by Network-1. Such adjustment shall be made
successively whenever such a record date is fixed, and in the event that such
distribution is not so made, the Exercise Price shall again be adjusted to be
the Exercise Price which would then be in effect if such record date had not
been fixed.

     (c) No adjustment in the Exercise Price shall be required unless such
adjustment would require a decrease of at least one cent ($0.01) in such price;
provided, however, that any adjustment which by reason of this Section 7(c) is
not required to be made shall be carried forward and taken into account in any
subsequent adjustment. All calculations under this Section 7 shall be made to
the nearest cent or to the nearest one-hundredth of a share, as the case may be,
but in no event shall Network-1 be obligated to issue fractional shares of
Common Stock or fractional portions of any securities issuable upon the exercise
of the Option.

     (d) In the event that at any time, as a result of an adjustment made
pursuant to Section 7 hereof, the Holder of the Option thereafter exercised
shall become entitled to receive any shares of capital stock, options, warrants
or other securities of Network-1 other than the shares of Common Stock,
thereafter the number of such other shares of capital stock, options, warrants
or other securities so receivable upon exercise of this Option shall be subject
to adjustment from time to time in a manner and on terms as nearly equivalent as
practicable to the provisions with respect to the shares of Common Stock
contained in this Section 7, and the provisions of this Option Agreement with
respect to the shares of Common Stock shall apply, to the extent applicable, on
like terms to any such other shares of capital stock, options or warrants or
other securities.

     (e) Upon each adjustment of the Exercise Price as a result of calculations
made in this Section 7, the Option outstanding immediately prior to the making
of such adjustment shall

                                        4


thereafter evidence the right to purchase, at the adjusted Exercise Price, that
number of Option Shares (calculated to the nearest hundredth), obtained by (i)
multiplying the number of Option Shares purchasable upon exercise of the Option
immediately prior to such adjustment of the Exercise Price by the Exercise Price
in effect immediately prior to such adjustment and (ii) dividing the product so
obtained by the Exercise Price in effect immediately after such adjustment of
the Exercise Price.

     (f) In case of any capital reorganization of Network-1 or of any
reclassification of shares of Common Stock (other than as a result of
subdivision or combination) or in case of the consolidation of Network-1 with,
or the merger of Network-1 into, any other corporation (other than a
consolidation or merger in which Network-1 is the continuing corporation) or of
the sale of the properties and assets of Network-1 as, or substantially as, an
entirety, the Option shall, after such reorganization, reclassification,
consolidation, merger or sale, be exercisable, upon the terms and conditions
specified herein, for the number of shares of Common Stock or other capital
stock, options or warrants or other securities or property to which a Holder (at
the time of such reorganization, reclassification, consolidation, merger or
sale) upon exercise of such Option would have been entitled upon such
reorganization, reclassification, consolidation, merger or sale; and in any such
case, if necessary, the provisions set forth in this Section 7(f) with respect
to the rights and interests thereafter of the Holder shall be appropriately
adjusted so as to be applicable, as nearly as may reasonably be, to any shares
of Common Stock or other capital stock or options, warrants or other securities
or property thereafter deliverable upon the exercise of the Option. The
subdivision, reverse split or combination of shares of Common Stock at any time
outstanding into a greater or lesser number of shares shall not be deemed to be
a reclassification of the Common Stock for the purposes of this Section 7(f).

     (g) In any case in which this Section 7 shall require that an adjustment in
the Exercise Price be made effective as of a record date for a specified event,
Network-1 may elect to defer until the occurrence of such event issuing to the
Holder, if such Holder exercised any portion of this Option after such record
date, shares of capital stock or other securities of Network-1, if any, issuable
upon such exercise over and above the shares of Common Stock or other securities
issuable, on the basis of the Exercise Price in effect prior to such adjustment;
provided, however, that Network-1 shall deliver to the holder a due bill or
other appropriate instrument evidencing such Holder's right to receive such
shares of Common Stock or other securities upon the occurrence of the event
requiring such adjustment.

     SECTION 8. Fractional Shares

     Upon exercise of the Option, Network-1 shall not be required to issue
fractional shares of Common Stock or other capital stock. In lieu of such
fractional shares, the Holder shall receive an amount in cash equal to the same
fraction of the (i) current Market Price of one whole share of Common Stock if
clause (i), (ii) or (iii) in the definition of Market Price in Section 3(c)
hereof is applicable or (ii) book value of one whole shares of Common Stock as
reported in Network-1's most recent audited financial statements if clause (iv)
in the definition of Market Price in Section 3 above is applicable. All
calculations under Section 7 shall be made to the nearest cent.

                                        5


     SECTION 9. Securities Act Legend

     The Holder shall not be entitled to any rights of a stockholder of
Network-1 with respect to any Option Shares purchasable upon the exercise of
this Option, including voting, dividend or dissolution rights, until such Option
Shares have been paid for in full. As soon as practicable after such exercise,
Network-1 shall deliver a certificate or certificates for the securities
issuable upon such exercise, all of which shall be fully paid and nonassessable,
to the person or persons entitled to receive the same; provided, however, that,
if the Option Shares are not registered under the Securities Act, such
certificate or certificates delivered to the Holder of the surrendered Option
shall bear a legend reading substantially as follows:

     "These securities have not been registered under the Securities Act of
1933, as amended, or the securities laws of any state and may not be sold or
transferred in the absence of such registration or any exemption therefrom under
such Act and laws, if applicable. Network-1, prior to permitting a transfer of
these securities, may require an opinion of counsel or other assurances
satisfactory to it as to compliance with or exemption from such Act and laws."

     SECTION 10. Transfer

     All or a portion of this Option may be transferred, sold or assigned by
Holder without the consent of Network-1 provided, that, Holder provides
Network-1 with evidence reasonably satisfactory to it that such transfer is not
in violation of the Securities Act of 1933, as amended (the "Act"). With respect
to any such transfer, sale or assignment, Holder shall execute and deliver to
Network-1 the Form of Assignment attached hereto.

     SECTION 11. Taxes; Expenses

     Network-1 shall pay all taxes and expenses that may be payable in
connection with the preparation, issuance and delivery of Options Shares under
this Stock Option Agreement.

     SECTION 12. Notice of Adjustment

     (a) Upon any adjustment of the Exercise Price pursuant to Section 7 hereof,
Network-1, within 30 calendar days thereafter, shall have on file for inspection
by the Holder a certificate of the Board of Directors of Network-1 setting forth
the Exercise Price after such adjustment, the method of calculation thereof in
reasonable detail, the facts upon which such calculations were based and the
number of Option Shares issuable upon exercise of the Option after such
adjustment in the Exercise Price, which certificate shall be conclusive evidence
of the correctness of the matters set forth therein.

     (b) In case:

     (i) Network-1 shall authorize the issuance to all holders of shares of
Common Stock of rights, options, warrants or other securities to subscribe for
or purchase capital stock of Network-1 or of any other subscription rights,
options, warrants or other securities; or

     (ii) Network-1 shall authorize the distribution to all holders of shares of
Common Stock of evidences of its indebtedness or assets; or

                                        6


     (iii) of any consolidation or merger to which Network-1 is a party and for
which approval of any stockholders of Network-1 is required, of the conveyance
or transfer of the properties and assets of Network-1 substantially as an
entirety or of any capital reorganization or any reclassification of the shares
of Common Stock (; or

     (iv) of the voluntary or involuntary dissolution, liquidation or winding up
of Network-1; or

     (v) Network-1 proposes to take any other action which would require an
adjustment of the Exercise Price pursuant to Section 7 above;

     then, in each such case, Network-1 shall give to the Holder at its address
appearing below at least 20 calendar days prior to the applicable record date
hereinafter specified in (A), (B), or (C) below, by first class mail, postage
prepaid, a written notice stating (A) the date as of which the holders of record
of shares of Common Stock entitled to receive any such rights, options, warrants
or distribution are to be determined or (B) the date on which any such
consolidation, merger, conveyance, transfer, reorganization, reclassification,
dissolution, liquidation or winding up is expected to become effective, and the
date as of which it is expected that holders of record of shares of Common Stock
shall be entitled to exchange such shares for securities or other property, if
any, deliverable upon such consolidation, merger, conveyance, transfer,
reorganization, reclassification, dissolution, liquidation or winding up or (C)
the date of such action which would require an adjustment of the Exercise Price.
The failure to give the notice required by this Section 12 or any defect therein
shall not affect the legality or validity of any such issuance, distribution,
consolidation, merger, conveyance, transfer, reorganization, reclassification,
dissolution, liquidation, winding up or other action or the vote upon any such
action.

     Except as provided herein, nothing contained herein shall be construed as
conferring upon Holder the right to vote on any matter submitted to the
stockholders of Network-1 for their vote or to receive notice of meetings of
stockholders or the election of directors of Network-1 or any other proceedings
of Network-1, or any rights whatsoever as a stockholder of Network-1.

     SECTION 13. Notices

     Any notice, request, demand or other communication pursuant to the terms of
this Stock Option Agreement shall be in writing and shall be sufficiently given
or made when delivered or mailed by first class or registered mail,
postage-prepaid, to the following addresses:

If to Network-1:
                                Network-1 Security Solutions, Inc.
                                445 Park Avenue, Suite 1028
                                New York, New York 10022

                                        7


with a copy to:
                                Eiseman Levine Lehrhaupt & Kakoyiannis, P.C.
                                805 Third Avenue, 10th Floor
                                New York, NY  10022
                                Attn:  Sam Schwartz, Esq.


If to Holder:
                                Corey M. Horowitz.
                                1085 Park Avenue
                                New York, New York  10128


     SECTION 14. Miscellaneous

     (a) Waiver. At any time the parties hereto may (a) extend the time for the
performance of any of the obligations or other acts of the other parties hereto,
(b) waive any inaccuracies in the representations and warranties contained
herein by the other party or (c) waive compliance with any of the agreements or
conditions contained herein. No failure on the part of any party to exercise any
power, right, privilege or remedy under this Stock Option Agreement, and no
delay on the part of any party in exercising any power, right, privilege or
remedy under this Stock Option Agreement, shall operate as a waiver of such
power, right, privilege or remedy; and no single or partial exercise of any such
power, right, privilege or remedy shall preclude any other or further exercise
thereof or of any other power, right, privilege or remedy. No party shall be
deemed to have waived any claim arising out of this Stock Option Agreement, or
any power, right, privilege or remedy under this Stock Option Agreement, unless
the waiver of such claim, power, right, privilege or remedy is expressly set
forth in a written instrument duly executed and delivered on behalf of such
party; and any such waiver shall not be applicable or have any effect except in
the specific instance in which it is given.

     (b) Entire Agreement. Except as otherwise set forth in this Stock Option
Agreement and the other documents referred to herein, collectively contain the
entire understanding of the parties hereto with respect to the subject matter
contained herein and supersede all prior agreements and understandings, oral and
written, with respect thereto.

     (c) Binding Effect; Benefit. This Stock Option Agreement shall inure to the
benefit of and be binding upon the parties hereto and nothing in this Stock
Option Agreement, expressed or implied, is intended to confer on any person or
entity other than the parties hereto or their respective successors and
permitted assigns, any rights, remedies, obligations or liabilities under or by
reason of this Stock Option Agreement.

     (d) Amendment and Modification. Subject to applicable law, this Stock
Option Agreement may only be amended, modified and supplemented by a written
agreement duly executed the parties hereto.

                                        8


     (e) Further Actions. Network-1 shall use its best efforts to take, or cause
to be taken, all appropriate action, and to do, or cause to be done, all things
necessary, proper or advisable under applicable laws and regulations to
consummate and make effective the transactions contemplated hereunder and to
carry out the interest and purposes of this Stock Option Agreement, including,
without limitation, using its reasonable best efforts to obtain all licenses,
permits, consents, approvals, authorizations, qualifications and orders of
governmental entities.

     (f) Applicable Law. This Stock Option Agreement and the legal relations
between the parties hereto shall be governed by, and construed in accordance
with, the laws of the State of New York, without regard to the conflicts of laws
rules thereof.

     (g) Dispute Resolution. The parties hereto will use their best efforts to
resolve by mutual agreement any disputes, controversies or differences that may
arise from, under, out of or in connection with this Agreement. If any such
disputes, controversies or differences cannot be settled between the parties
hereto, they will be finally settled by final and binding arbitration to be
conducted by an arbitration tribunal in New York City, New York, pursuant to the
rules of the American Arbitration Association. The arbitration tribunal will
consist of three arbitrators. The decision or award of the arbitration tribunal
will be final, and judgment upon such decision or award may be entered in any
competent court or application may be made to any competent court for judicial
acceptance of such decision or award and an order of enforcement. In the event
of any procedural matter not covered by the aforesaid rules, the procedural law
of New York will govern. The prevailing party in arbitration shall be entitled
to receive a reasonable sum for its attorneys' fees and all other reasonable
costs and expenses incurred in such action or suit.

     (h) Severability. Any term or provision of this Stock Option Agreement that
is invalid or unenforceable in any situation in any jurisdiction shall not
affect the validity or enforceability of the remaining terms and provisions
hereof or the validity or enforceability of the offending term or provision in
any other situation or in any other jurisdiction. If the final judgment of a
court of competent jurisdiction declares that any term or provision hereof is
invalid or unenforceable, the parties hereto agree that the court making the
determination of invalidity or unenforceability shall have the power to reduce
the scope, duration or area of the term or provision, to delete specific words
or phrases or to replace any invalid or unenforceable term or provision with a
term or provision that is valid and enforceable and that comes closest to
expressing the intention of the invalid or unenforceable term or provision, and
this Stock Option Agreement shall be enforceable as so modified after the
expiration of the time within which the judgment may be appealed.

(i) Non-exclusivity. The rights and remedies of Network-1 and Holder under this
Stock Option Agreement are not exclusive of or limited by any other rights or
     remedies which either of them may have, whether at law, in equity, by
contract
or otherwise, all of which shall be cumulative and not alternative.

                                        9


     IN WITNESS WHEREOF, an authorized officer of Network-1 has signed and
delivered this Option as of the date first written above.



                                      NETWORK-1 SECURITY SOLUTIONS, INC.



                                      By:
                                          --------------------------------------
                                          David C. Kahn, Chief Financial Officer



























                                       10


                              ELECTION TO EXERCISE

(To be executed by the registered holder if such holder desires to exercise the
within Option)

To:  NETWORK-1 SECURITY SOLUTIONS, INC.
     445 Park Avenue, Suite 1028
     New York, New York  10022


The undersigned hereby (1) irrevocably elects to exercise its right to exercise
_____ shares of Common Stock covered by the within Option, (2) makes payment in
full of the Exercise Price by enclosure of a certified check or (3) elects a
cashless exercise, (4) requests that certificates for such shares be issued in
the name of:

Please print name, address and Social Security or Tax Identification Number:

------------------------------------------------

------------------------------------------------

------------------------------------------------

and (5) if said number of shares shall not be all the shares evidenced by the
within Option, requests that a new Option Agreement for the balance of the
shares covered by the within Option be registered in the name of, and delivered
to:

Please print name and address:

------------------------------------------------

------------------------------------------------

------------------------------------------------

In lieu of receipt of a fractional shares of Common Stock, the undersigned will
receive a check representing payment therefor.

Dated: _____________________

                                           By: ______________________________



                                       11


                               FORM OF ASSIGNMENT

     FOR VALUE RECEIVED __________________, hereby sells, assigns and transfers
to (Social Security or I.D. No. ______________) the within Option, or that
portion of this Option purchasable for ________ shares of Common Stock together
with all rights, title and interest therein, and does hereby irrevocably
constitute and appoint ______________ ______________ attorney to transfer such
Option on the register of Network-1 Security Solutions, Inc., with full power
and substitution.

                                                  ______________________________
                                                           (Signature)


Dated: ___________, 20__

Signature Guaranteed:



_________________________













                                       12


                                    EXHIBIT B
                                    ---------

               Calculation of Horowitz (CMH) Derivative Percentage
               ---------------------------------------------------

Common Stock                                                        19,764,724

Options and Warrants  (includes options to purchase minimum
750,000 shares pursuant to Horowitz Employment Agreement)           10,031,481

Total Fully Diluted                                                 29,796,205

Corey Horowitz/CMH Options/Warrants                                  6,398,486

Horowitz (CMH) Derivative Percentage                                    21.47%


               List of Horowitz/CMH Network-1 Options and Warrants
               ---------------------------------------------------


  Owner/Type         Date of Grant       Number     Exercise Price    Expiration
  ----------         -------------       ------     --------------    ----------

Horowitz/Option        10/20/98          20,000         $6.00          10/20/11*

Horowitz/Option         6/22/99          10,000          3.75           6/22/09

Horowitz/Option        10/25/99           7,500          4.25          10/25/09

Horowitz/Option         9/19/00           5,000          5.50           9/19/10

Horowitz/Option         1/19/01          10,625        3.0625           1/19/11

CMH/Warrant             7/11/01         300,000          0.70           7/11/11

CMH/Warrant            10/08/01         250,000          1.48          10/08/10*

CMH/Option              4/18/02         750,000          1.20           4/18/10*

Horowitz/Option        12/22/03       1,084,782          0.23          12/22/11*

Horowitz/Option        12/22/03         515,218          0.13          12/22/11*

Horowitz/Option        11/26/04       1,100,000          0.25          11/26/14

Horowitz/Option        11/26/04         400,000          0.68          11/26/09

Horowitz/Option         3/16/05       1,195,361          1.18           3/16/12

Horowitz/Option         2/28/07         750,000**       $1.60           2/28/12

                       ------------------------
                          Total       6,398,486

-------------------------
*    Reflects expiration date extension of 3 years as per Employment Agreement.

**   Includes options to purchase an aggregate of a minimum of 750,000 shares to
     be issued in accordance with Mr. Horowitz's employment agreement, dated
     February 28, 2007, 375,000 of such options were issued on 2/28/07 and a
     minimum 375,000 of such options are to be issued on 2/28/08, subject to the
     terms of the employment agreement.