SIMPLE ENCRYPTION USING XOR
[needs checking]
************************************************************
function Encrypt(const S: String; Key: Word): String;
var
I: byte;
begin
Result[0] := S[0]; //*******
for I := 1 to Length(S) do begin
Result[I] := char(byte(S[I]) xor (Key shr 8));
Key := (byte(Result[I]) + Key) * C1 + C2;
end;
end;
function Decrypt(const S: String; Key: Word): String;
var
I: byte;
temp : string;
begin
temp[0] := S[0];
for I := 1 to Length(S) do begin
temp[I] := char(byte(S[I]) xor (Key shr 8));
Key := (byte(S[I]) + Key) * C1 + C2;
end;{for}
result := temp;
end;
possibly replace the asterisked line above with this line:
SetLength(Result, Length(S));
Since "If you leave that out, you will get problems.
Without it, your Result string has either a random length
or a length of 0 (I don't remember which right now).
So your Result[I] lines will try to change a non-existent
character and raise an error".
************************************************************
see also code in Richards Writer's Toolkit
************************************************************
At 10:28 12/09/00 +0000, you wrote:
>Hi!
>
>Could anyone tell, where to find a component for encrypting/decrypting text.
>Please HELP!...
Hi Tomislav,
I recently spent hours looking around the 'Net and evaluating different
cryptography components. There is an excellent collection at
http://www.efg2.com/Lab/Library/Delphi/MathFunctions/Cryptography.htm
I found the "Delphi Encryption Compendium" listed on this page to be the best
collection of tools for what I wanted. It took a little painful work to get
them up and running, but it was well worth the effort.
hth,
Chris.
=====================================================
Intelligent Irrigation Systems Ph: 03 9739 4422
3/5 Clarke St Fax: 03 9739 4455
Lilydale Vic 3140 Mob: 0419 355 565
Australia http://www.cohort.com.au
=====================================================
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> Could anyone tell, where to find a component for encrypting/decrypting text.
> Please HELP!...
Try
http://www.scramdisk.clara.net
HTH
Martin Jambor
------------------------
Martin Jambor
Independent Developer
JamborM@iname.com
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> Try HyperString
http://efd.home.mindspring.com/tools.htm
Glenn Crouch mailto:glenn@esbconsult.com.au ICQ:36017076
ESB Consultancy, http://www.esbconsult.com.au
Home of ESBPCS, ESBStats, ESBPDF Analysis & ESBCalc
Kalgoorlie-Boulder, Western Australia
(TeamND, TeamOE, Addict Support, eLists.org Management)
****************************************************************
An excellent, free encryption library:
DCPcrypt:
http://www.scramdisk.clara.net/
(click on the Delphi link)
****************************************************************
Check
http://www.multimania.com/sirius29/algos.html