There are basically two hashing algorithms for cryptocurrencies: SHA-256 and scrypt. SHA-256 is the one used for Bitcoin and its derivatives. Litecoin uses t

There are basically two hashing algorithms for cryptocurrencies: SHA-256 and scrypt. SHA-256 is the one used for Bitcoin and its derivatives. Litecoin uses the scrypt algorithm, as does its derivatives, like Worldcoin. There are a handful of other proof of work algorithms as well used by a few other currencies. Side note, check out namecoin: http://en.wikipedia.org/wiki/Namecoin http://en.wikipedia.org/wiki/Namecoin. It's based on SHA-256. scrypt uses the SHA-256 algorithm for hashing the blocks, but the caveat is that it also uses a high number of read/writes to RAM. In fact, there is very nearly parity to the number of compute cycles to read/writes cycles. Here's the paper on it: http://www.tarsnap.com/scrypt/scrypt.pdf http://www.tarsnap.com/scrypt/scrypt.pdf. In order to build an ASIC miner for Litecoin, one would have to build a circuit that had a massive number of CPUs encrusted with a fairly massive amount of fast RAM. As this more or less describes a video card, whoever designs an ASIC for Litecoin will have a nice challenge in front of them. Edit: Working URLs