How to encrypt and decrypt a C data at run time

[sweety]

Dear All,

I need to encrypt a C data file(Filled structure data and int, enums).
and make a bin file. The at anypoint of time i've to read this .bin
file and have to decrypt and have to read the structure ad enum values
back.

So, any help on writing an encryption and decryption methods can do for
C data's.

Quick help Would be great , sample encryption/decryption code will also
be a grt help.

Thanks,
Sweety.

[osmium]

"sweety" wrote:

I need to encrypt a C data file(Filled structure data and int, enums).
and make a bin file. The at anypoint of time i've to read this .bin
file and have to decrypt and have to read the structure ad enum values
back.

So, any help on writing an encryption and decryption methods can do for
C data's.

Quick help Would be great , sample encryption/decryption code will also
be a grt help.

I assume this is a student assignment. You might start here:

http://en.wikipedia.org/wiki/Vigen%C3%A8re_cipher

And after absorbing part of that do a Google search for <autokey vigenere>.
I would expect you to find some code after a while, but it would be more fun
to write it yourself. The computer part of it is no great mystery:make a
truth table for what the exclusive or operator does and apply the results..