Quote from: ShadowOfHarbringer on October 07, 2013, 02:45:52 PM

So for practical usage it has not yet been really achieved. That's what i wanted to say.

Anyway, it would be extremely cool to have homomorphic encryption as it would enable ultimate blockchain compression (there was a topic here claiming that).

Actually Gentry and his colleagues didn't stop after 2009. There have been big advances in the efficiency of FHE since then. Also people are exploring hardware acceleration for it. I'm talking very vaguely because I sort of scan read some of the papers and let the general gist digest in my mind, but the maths is extremely advanced and I'm not actually a mathematician.

If you're interested in such topics, the best place to follow crypto research is here:

http://eprint.iacr.org/eprint-bin/search.pl?last=31&title=1

It's a rolling archive of crypto research, updated every few days. For example, here's a recent paper on the speed of FHE when combined with FPGAs:

http://eprint.iacr.org/2013/624.pdf

They get a 26x speedup for integer based FHE, which is itself orders of magnitude better than Gentry's lattice based scheme.

However I don't think it will be interesting for Bitcoin any time soon. It's important not to underestimate the incredible value Bitcoin derives from using simple, totally ordinary cryptographic constructs that any first-year CS student can understand.