help for simple encryption and decryption? [For Mac]

hi all,

i m creating a html file in my application.

is there any classes in Cocoa for simple file encryption/decryption? I just need something I can point at a file on disk and do simple encryption without a password or key and then decode it later. Doesn't have to be fancy or even all that secure - just something simple and easy to use.

please help me for this.

if possible please provide me any example.

thanks in advance.