User:Qed

Qed means Quod Erat Demonstrandum.

I maintain a couple websites worth visiting:


 * My personal website
 * The Better String Library

Pay no attention to the below. I have no idea where else to put a library of "editing tricks for Wikipedia".

Implementation tricks
When developing algorithms for Galois field computation on small Galois fields, a common performance optimization approach is to find a generator g and use the identity:


 * $$ab = g^{\log_g(ab)} = g^{\log_g (a)+\log_g (b)}$$

to implement multiplication as a sequence of table look ups for the logg(x) and g(x) functions and an integer addition operation. This exploits the property that all finite fields contain generators. In the Rijndael field example, the polynomial x + 1 (or {03}) is one such generator, since it is irreducible.