This is a collection of very simple number-theory related tools and a very simple RSA encryption and cracking tool.

'ntheory.rb' - this contains various simple utility algorithms.

• GCD, EGCD, Totient, Coprimality.
• Modular exponentiation (and a simple equivalent which handles this similarly to how it is done by hand.)
• Simple prime factorisation.
• Miller-Rabin primality test.

'rsaenc.rb' - this contains a simple RSA encryption tool. 'rsaenc-cmd' - this can be run to actually encrypt things.

'rsasolve.rb' - this is a simple solver for RSA (uses the tools above to decrypt messages with their public key).