prime number (almost prime, in fact 23x4349) - to avoid as much collisions as possible.

Why 100027?

I wasn't going for code golf here, but yes, that would work too.

you could use alias instead of alias_method here (You are not going to subclass this class I hope) :)

Very nice. This code can even pass code review from Lead :)

What do you think about my solution? It doesn't need an information about salt.

Works with random salt.

not as fast as Bareiss, 'cause of float operations. can be rewritten to use lcm on columns, instead of division.

Almost Hash. But with Array, and using some field math.