Graham Banks wrote:
Andrej Sidorov:
Its interesting that Rajlich doesn't have and doesn't want to read sources of Strelka that Osipov offered to send him.
Tony Thomas:
He said that without even looking at the sources. What a pity.
Thanks Graham, that works.
To Tony and Andrej:
You have a point there, but I think a chessprogram author like Vas, who is working on his program practically every night and day, probably knows it better than he knows his own mind. If Strelka is really a completely re-engineered Rybka, the 'new'
sources would probably not make much sense to even Vas, let alone if some of its inner working are deliberately obfuscated to look like tables of some sort, but really aren't.
It is also possible that taken from Rybka are only some parts that were really new or different, real but maybe small breakthroughs, and that this was combined with other parts, from other programs. Hiding the crucial parts would possibly not be very difficult if it was some small piece of code.
That other programs were combined I believe seems obvious enough if you look at some of the original output of Strelka 1.0 and 1.8, but is difficult to prove and not really relevant to the cloning of Rybka code. Some of this was evident from the sources I suppose and from what Dann Corbit told us, parts of Beowulf for instance are in the Winboard interface.
But in other words: Vasik would probably be able to say much more by watching how Strelka actually plays, he is a strong chessplayer himself and he would certainly know what to look for. You can "obfuscate" all you want but the final program still has to play chess.
The second point of attack; Vasik could have learnt more if he took the trouble of looking at Strelkas machinecode, as this would necessarily not be encrypted anymore once running and some keyparts would certainly be recognizable for him. But I don't even think that Vasik did this, the way the program plays and the output that in some instances was still
very much like Rybka, we all know that, would have been enough I think. For Vasik it would be.
My best,
Eelco
