Read Me

For discussion about security of tinycrypt, see http://eprint.iacr.org/2002/067.

TinyCrypt was written by Bill Cox, and placed into the public domain.  Feel free to use it without
any copyright worries.  However, be sure to realize that MiniLZO uses the GNU copyright!  See
COPYING in the minilzo directory.

To build TinyCrypt, just un-tar and un-zip the tinycrypt archive, go to the tinycrypt directory,
and type:

    make

The three executables are tinycrypt, testARC4, and modcrypt.  TestARC4 just verifies that the
lower-level ARC4 ("alleged RC4") implementation works.  Tinycrypt, in comparison, compresses the
file, obfuscates it, and then applies the SimpleCrypt encryption algorithm.  This should be secure
enough for commercial use.  Modcrypt is my own modified version of ARC4 which I hope performs
better and encrypts better, but which has and probably never will be well verified.

To use tinycrypt, type:

    tinycrypt file

It will ask you for your password twice, just to confirm the spelling, and then create file.enc.
This file is a binary encrypted file.  The original plain-text file is not deleted.

To decrypt a .enc file, just type:

    tinycrypt file.enc

Again, it will ask for a password, but only once.  It will create 'file' without the '.enc'
extension, but it will not delete the encrypted file.

TinyCrypt does the following to help be more secure than plain ARC4:

- Includes a nonce value of 20 bytes (from /dev/urandom)
- Discards 768 bytes

As a fun challenge, consider trying to decrypt challenge.enc, encrypted with the original
modcrypt.  I'm not rich enough to offer any decent prize, but I'll send you $200, and can the
algorithm!