Very Computer

Does anyone know of any third party software for encrypting security  
access code files?  We have developed an executable but do not want to  
put the file in the EXE because users will be added on a regular  
basis.  Any help is appreciated.

Quote:

>Does anyone know of any third party software for encrypting security  
>access code files?  We have developed an executable but do not want to  
>put the file in the EXE because users will be added on a regular  
>basis.  Any help is appreciated.

Do you need "strong" crypto or can something simpler do for you? If you
need something simply to keep a casual viewer from making sense of, you
can do some string manipulation of some sort. I wrote a bit-wise XOR
function for this sort of thing, simple security, and used what is called
a "rolling key" to generate the key used to XOR the string and then store
it. A nice thing about XOR is that the same password is used both ways
and works like this:

(String A) XOR (PassWord) = (String B)
(String B) XOR (PassWord) = (String A)

The function I wrote converted the ascii value of a character to binary,
converted the password first character to binary, dod an XOR at the
binary bit level, converted binary back to ascii and then stored the
resulting character. Since the same password (in my case a long phrase
that was very easy for ME to remember) is used both ways, a short
function can be used easily. I passed the function the string I wanted to
encode and a number which was the character position in the key to use as
a starting point. Each user had a person ID in the system which ended up
giving each their own starting point in the key. Later, I could decode
the encrypted data and determine WHO had stored it. This was NOT a
requirement of the system, only that a casual user not be able to see
anything meaningful and that one person could not decode certain
pieces of data stored by another in certain fields. I later modified the
field structure to add a few bits to not even show the data at all if the
user could not decode it. Again, not a requirement, but it cleaned up the
screen a lot.
--
Ralph
... and NO, I speak for no one else but me, myself and I, of course.
Ratz! "They" lost the contract! This address may no longer be in
service after 1600 PDT, June 16, 1995.

Encryption can be accomplished using NetLib for FoxPro (Pinnacle Publishing)

Subject: Encrypting FoxPro DBFs

Date: 25 May 1995 14:01:44 GMT

writes:

Quote:>Does anyone know of any third party software for encrypting security  
>access code files?  We have developed an executable but do not want to  
>put the file in the EXE because users will be added on a regular  
>basis.  Any help is appreciated.

NetLib for Windows and DOS, has a set of encryption routines.  You can
either encrypt
existing files or encrypt files as they are created, works with all file
types. You
have the ability to specify encryption keys.  I've designed an e-mail app
which
creates new user mailboxes on the fly, which are encrypted upon creation.
 The fact
that the file is encrypted is transparent to the user, decryption is
immediate upon
opening the file.

There are various libraries available depending on what you want to
do. A library called CIPHER is available on CI$ will encrypt string
values. NETLIB from pinnacle publishing allows .DBF encryption.

Hope this helps.

Menachem

+----------------------------------+
| Menachem Bzian, CPA              |
| Flash Creative Management, Inc.  |

+----------------------------------+

: There are various libraries available depending on what you want to
: do. A library called CIPHER is available on CI$ will encrypt string
: values. NETLIB from pinnacle publishing allows .DBF encryption.

i also found it at lenti.med.umn.edu in /pub/foxpro.

Check out Cryptor from Xitech in Orlando, Florida, phone 407-855-2250.