Seriously, Google.
Blowfish and 3DES are both encryption algorithms (block ciphers, working on blocks of input instead of streams of bits). 3DES is a variant of DES but using three 56-bit keys since DES with a single 56bit key is now insecure. 3DES hasn't been 'broken' but is to be replaced by the AES (advanced encryption standard), based on the Rijndael cipher.
Blowfish is open, license free and considered secure at the minute. It supports variable key lengths up to 448 bits (a keyspace some 2^280 times larger than 3DES).
MD5 is a hash algorithm. It takes in abitrary amounts of data and spits out a fixed-length representation of it. It, like all hash algorithms, is one way. That is to say that
- For a given hash h(m), it is computationally infeasible to find m (the pre-image of h(m))
- For a given hash h(m), it is computationally infeasible to find x such that h(x) = h(m) (2nd preimage)
- It is computationally infeasible to find two messages x1 and x2 such that h(x1) = h(x2) for x1 =/= x2 (collision resistance)
Google for the ISAAC one, that's just goddamn laziness. It's a random number generator, not a hash algorithm so not comparable. It's uses include crypto (initialisation vectors and the like, I would imagine) and Monte Carlo simulations.
Re: Encryption Algorithm
Linear Mode
