Douglas F. Elznic and Lucky Green have both written saying that www.distributed.net will not be devoting their full effort to the DES II challenge. This is incorrect. www.distributed.net is a highly centralized effort, in which clients are almost completely controlled by the central site, with which they are in frequent communication. Over the past few weeks, the clients have been upgraded to a version containing dual search cores - they can search either rc5-64 or an arbitrary DES key. On the morning of the 13th, as soon as the DES II challenge data becomes available, their servers will stop issuing rc5-64 blocks and start issuing DES II blocks. The clients will all switch over to the DES II contest without any action by the owners of the client machines. I too would like to see a serious effort made at a 512 bit RSA key. However, the infrastructure for this is quite a bit more complex than a simple bruteforce against a symmetric key, and the organizers of d.n don't seem to be ready for it. My greatest fear with DES II is that if d.n finds the key early in the search, they may decide to sit on it until just before the 540 hour deadline. If they are the only group with a credible chance of finding the key (as far as I know, this is the case), then their payback is maximized by by this tactic, since the time limits for the June contest are determined by the speed with which the key is found in January. My personal impression is that d.n seems more motivated by the money, which they want to further their research on distributed computing, than they are by ideology. The above represent my personal, private views, and should neccesarily be attributed to my employer. Peter Trei trei@ziplink.net ptrei@hotmail.com (more reliable next week)