Exhibit 10.6
                            LAURUS MASTER FUND, LTD.
                          825 Third Avenue, 14th Floor
                            New York, New York 10022


                                                           August 19, 2004


SDA AMERICA, INC.
230 Park Avenue, 10th Floor
New York, NY 10169
Attn:  Jay McDaniel


     Re:  Restricted  Account:  Account  Number  2704051693,

     Account  Name:  SDA  America,  Inc.,  maintained  at North  Fork  Bank (the
     "Restricted Account").



     This letter will amend, restate and replace our letter agreement of May 28,
2004  concerning  the use of  funds in the  Restricted  Account  (the  "Existing
Restricted  Account  Side  Letter").  Reference  is  made  to (i)  that  certain
Securities  Purchase  Agreement,  dated as of May 28, 2004 (as amended on August
19, 2004, the "Purchase Agreement"),  by and among Secured Digital Applications,
Inc., a Delaware  corporation  (the  "Parent"),  SDA  AMERICA,  INC., a Delaware
corporation  (the  "Company"),  and Laurus Master Fund,  Ltd. (the  "Purchaser")
relating to the issuance of the Series A Preferred  referred to therein and (ii)
that certain Restricted Account Agreement, dated as of May 28, 2004 (as amended,
modified or supplemented from time to time, the "Restricted Account Agreement"),
by and among the Company,  Laurus and North Fork Bank (the "Bank").  Capitalized
terms used but not defined  herein shall have the meanings  ascribed them in the
Purchase Agreement or the Restricted Account Agreement, as applicable.  Pursuant
to the Section 3.2 of the Purchase Agreement,  the Company has placed $6,500,000
in the Restricted  Account,  and, subject to the provisions of this letter,  the
Purchase  Agreement  and any Related  Agreement,  maintained  such amount in the
Restricted  Account  for as long as the  Purchaser  shall  hold any  outstanding
Series A Preferred.  Furthermore, the Company has pledged the Restricted Account
for  the  benefit  of the  Purchaser  as  security  for the  performance  of the
Parent's, the Company's and each of their respective  Subsidiaries'  obligations
to the  Purchaser  under the  Purchase  Agreement,  the Related  Agreements  and
certain other agreements between the Parent, certain of its Subsidiaries and the
Purchaser.

     The Purchaser and the Company desire to clarify certain  aspects  regarding
the  use  of  funds   contained  in  the  Restricted   Account,   and  for  good
consideration,  the receipt and sufficiency of which is here  acknowledged,  the
Company and the Purchaser  agree that,  (x) to the extent that either the Parent
or any of its  Subsidiaries  wish  to  utilize  the  proceeds  of the  Series  A
Preferred for the purposes set forth in Section 6.5(a) of the Purchase Agreement
or (y) promptly following any conversion of any amount of the outstanding Series
A Preferred into Common Stock of the Company (such event, a  "Conversion"),  the
Purchaser shall direct the Bank, pursuant to a Release Notice (as defined in the
Restricted Account Agreement), to wire an amount of funds equal to (i) amount of
the funds to be utilized in the  acquisition  or (ii) the  corresponding  dollar
amount by which the aggregate Stated Value of all outstanding Series A Preferred
Shares  has been  reduced  pursuant  to such a  Conversion  from the  Restricted
Account to such bank account as the Company may direct the Purchaser in writing.
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     Notwithstanding  anything  to the  contrary  contained  in  the  Restricted
Account  Agreement,  Laurus will not  exercise  its right  under the  Restricted
Account  Agreement  to direct  payments  from the  Restricted  Account  to third
parties so as to cause a payment  to be made to any party  other than the Parent
unless (a) an Event of Default has occurred  pursuant to the terms of the Master
Security  Agreement  or (b) SDA America has  dissolved  in  accordance  with its
bylaws.

         The Company and Laurus further agree that they will execute such
amendments to the Restricted Account Agreement, and will use commercially
reasonable efforts to cause the Bank to execute such amendments (which
commercially reasonable efforts shall not include the payment of any monies) as
are necessary and appropriate to affect the procedures contained in this side
letter agreement.


         This letter may not be amended or waived except by an instrument in
writing signed by the Company and the Purchaser. This letter may be executed in
any number of counterparts, each of which shall be an original and all of which,
when taken together, shall constitute one agreement. Delivery of an executed
signature page of this letter by facsimile transmission shall be effective as
delivery of a manually executed counterpart hereof or thereof, as the case may
be. This letter shall be governed by, and construed in accordance with, the laws
of the State of New York. This letter sets forth the entire agreement between
the parties hereto as to the matters set forth herein and supersede all prior
communications, written or oral, with respect to the matters herein.

     If the foregoing meets with your approval please signify your acceptance of
the terms hereof by signing below.

                                              Signed,

                                              Laurus Master Fund, Ltd.


                                              By:  /s/John Tucker
                                                   ---------------
                                              Name:   John Tucker
                                              Title:  Counsel


Agreed and Accepted this 19th day of August, 2004.

SDA AMERICA, INC.

By: /s/Patrick Soon-Hock Lim
    -------------------------
Name:  Patrick Soon-Hock Lim
Title: President


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