encryption

[Anon]

Not actually PHP but in fact Perl/CGI. I'm just asking this question here because I couldn't get an answer anywhere else and I figured that most PHP programmers are CGI veterans.

Lately I've been playing around with data encryption using XOR. However when certain pairs of characters are XORed:

b - 01100010
x - 01111000

c - 01100011
y - 01111001

• - 00110000
  0 - 00101010

just to name a few, they all produce a result of:

• 00011010

and this character almost seems to act as a marker for the termination of any document. When decrypting a document that contains this character it will translate everything but that character and everything after it. It does the same thing if put into a perl script.

print '';

this will give an error because it can't find the string terminator. it basically seems to end the document from where ever it is. I've tried using pieces of code to escape this character without actually using it (to no success), such as:

$var =~ s/(b ^ x)/(b ^ (b ^ x))/g;

$var =~ s/(should produce )/(should translate into whatever character it should decrypt to, in this case 'x')/g;

I don't suppose anyone would have any idea of how to fix this problem of mine?

[kparker]

You aren't perhaps suffering this sad fate under Windows, are you? The ascii value you mention just happens to be ^Z, which Windows, following DOS, following CP/M, (perhaps here too following RT-11) takes as an end-of-file marker in text files.

If you're going to encrypt in that manner, you must make sure everything understands it's dealing with binary data (00000000 is another possible bit pattern that might get strange treatment from things like C fgets!)