[GNU Crypto] My public domain Tiger hash implementation

[Philippe Verdy]

Note that I have spent some time to maximize the speed of the Tiger hash
function, and I wrote my own version nearly two years ago, that I published in a
Yahoo Group as a public domain version.

Recently I have reworked on it to find other possible optimizations and now it
really outperforms all existing implementations in Java (including the current
GNU Crypto version, and the commercial Cryptix version).

Also I developed a complete test and benchmark for it.
You may see it there:
http://groups.yahoo.com/group/the_gdf/files/Proposals/Working%20Proposals/HUGE/com.bitzi.util/

The two files are Tiger.java and TigerTest.java (which just contains a public
main() method).

You are allowed to change the package name or to change the internal API to
match with your class hierarchy.
Most of the optimizations present are there to maximize the reuse of local
variables, minimize accesses to member variables, and allow the java compiler to
use shorter bytecode instructions.
The interesting part for you will be the computeBlock() method which you could
copy.

I wrote it for the public domain, so you can integrate it and licence it with
the GNU Crypto GPL as a compatible derivative work. There's no company interest
in it, and this class is already used (in its past version) by several GPL'ed
projects.