lightweight encryption of text file

[Nobody]

On Sun, 10 Jan 2010 15:30:12 +0000, Steven D'Aprano wrote:

>> Thanks, this looks very simple too, but where is the decryption code?
>> Wikipedia seems to suggest that encryption and decryption are both the
>> same but running crypt on the output of crypt doesn't give back the
>> original string. So probably I'm misunderstanding something.
> 
> Yes, the nature of a stream cipher :)

It isn't limited to stream ciphers. You would have the same issue for
a block cipher with chaining (i.e. *not* ECB mode).