An algebraic hash function, inspired by the paper Hashing with SL2 by Tillich and Zemor.
The hash function is based on matrix multiplication in the special linear group
of degree 2, over a Galois field of order 2^127, with all computations modulo
the polynomial x^127 + x^63 + 1.
This construction gives some nice properties, which traditional bit-scambling
hash functions don't possess, including it being composable. It holds:
hash (m1 <> m2) == hash m1 <> hash m2
Following that, the hash function is also parallelisable. If a message can be divided
into a list of chunks, the hash of the message can be calculated in parallel:
mconcat (parMap rpar hash chunks)
All operations in this package are implemented in a very efficient manner using SSE instructions.
