Re: [viff-devel] FW: Bug in ViFF
Thanks for your early feedback. I am running ViFF 0.6 so I will upgrade right now and tell you whether the problem is still there. Sebastiaan -Original Message- From: Martin Geisler [mailto:[EMAIL PROTECTED] Sent: woensdag 1 oktober 2008 9:39 To: Hoogh, S.J.A. de Cc: viff-devel@viff.dk Subject: Re: FW: Bug in ViFF Hoogh, S.J.A. de [EMAIL PROTECTED] writes: Hi Sebastiaan, Thanks for giving VIFF some exercise! :-) Tomas Toft and I are using ViFF to analyze Toft's secure Linear Programming protocol. At the first sight everything seemed to work nicely, but when trying to increase the number of participants and the threshold we've found an annoying fact about ViFF: The threshold should be given explicitly when creating the runtime in any ViFF program. ViFF doesn't check whether this threshold matches with the parameters given in the configuration files. Wouldn't it be nicer if the threshold is read by create_runtime(id, players, threshold, options, Toft05Runtime) automatically? You mean that the threshold should be put in the player-X.ini files? I guess that is a good idea... As it is now, VIFF simply trusts you to get everything right -- it lets you pretend that you know what you are doing :-) The threshold used when generating config files determines the threshold for PRSS, whereas the threshold given to create_runtime determines the threshold for Shamir sharings. Now that I think of it, it seems natural to put both thresholds in the config files and unite them at the same time. Now doing this consistently and setting #players =3 and threshold =1 works and setting #players=5 and threshold=2 also works. However, there seems to be some bug somewhere when trying #players=5 and threshold=1. I've altered the millionaires.py such that it deals with 5 players instead of three and it provides correct output if threshold=2 but correct output for the participants 1, 2 and 3 only (and junk for players 4 and 5) if threshold=1... Hmm, that is bad... did you generalize millionaires.py so that there can be 4, 5, ... millionaires? How did you sort the inputs -- like it is done in sort.py? In addition, if I create the config-files with 5 players and threshold=1 and if I put threshold=2 in the millionaires program, it works again, i.e., provides correct output Hopefully, this information helps you finding the bug. If anything needs some clarification I'm happy to provide you more details... Is this with version 0.7, which was just released? Also, can you send us the modified millionaires.py program? I have recently tested multiplications with (n, t) = (25, 8) and it ran fine, but I must admit that I did not check that the results were correct, I only made sure that the benchmarks could be run. -- Martin Geisler millionaires-5.py Description: millionaires-5.py ___ viff-devel mailing list (http://viff.dk/) viff-devel@viff.dk http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk
Re: [viff-devel] FW: Bug in ViFF
Nope, Also with version 0.7 exactly the same problem occurs. Sincerely, Sebastiaan -Original Message- From: Martin Geisler [mailto:[EMAIL PROTECTED] Sent: woensdag 1 oktober 2008 9:39 To: Hoogh, S.J.A. de Cc: viff-devel@viff.dk Subject: Re: FW: Bug in ViFF Hoogh, S.J.A. de [EMAIL PROTECTED] writes: Hi Sebastiaan, Thanks for giving VIFF some exercise! :-) Tomas Toft and I are using ViFF to analyze Toft's secure Linear Programming protocol. At the first sight everything seemed to work nicely, but when trying to increase the number of participants and the threshold we've found an annoying fact about ViFF: The threshold should be given explicitly when creating the runtime in any ViFF program. ViFF doesn't check whether this threshold matches with the parameters given in the configuration files. Wouldn't it be nicer if the threshold is read by create_runtime(id, players, threshold, options, Toft05Runtime) automatically? You mean that the threshold should be put in the player-X.ini files? I guess that is a good idea... As it is now, VIFF simply trusts you to get everything right -- it lets you pretend that you know what you are doing :-) The threshold used when generating config files determines the threshold for PRSS, whereas the threshold given to create_runtime determines the threshold for Shamir sharings. Now that I think of it, it seems natural to put both thresholds in the config files and unite them at the same time. Now doing this consistently and setting #players =3 and threshold =1 works and setting #players=5 and threshold=2 also works. However, there seems to be some bug somewhere when trying #players=5 and threshold=1. I've altered the millionaires.py such that it deals with 5 players instead of three and it provides correct output if threshold=2 but correct output for the participants 1, 2 and 3 only (and junk for players 4 and 5) if threshold=1... Hmm, that is bad... did you generalize millionaires.py so that there can be 4, 5, ... millionaires? How did you sort the inputs -- like it is done in sort.py? In addition, if I create the config-files with 5 players and threshold=1 and if I put threshold=2 in the millionaires program, it works again, i.e., provides correct output Hopefully, this information helps you finding the bug. If anything needs some clarification I'm happy to provide you more details... Is this with version 0.7, which was just released? Also, can you send us the modified millionaires.py program? I have recently tested multiplications with (n, t) = (25, 8) and it ran fine, but I must admit that I did not check that the results were correct, I only made sure that the benchmarks could be run. -- Martin Geisler ___ viff-devel mailing list (http://viff.dk/) viff-devel@viff.dk http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk
