[viff-devel] [issue80] Broadcast
New submission from Janus Dam Nielsen janus.niel...@alexandra.dk: I would like to see a broadcast method in the Runtime class. The purpose of the broadcast method should be to distribute a public value among all parties (or some subset of parties). A case: All parties in a computation needs to read a value from standard in, and it is a different value for each party. We want to tell the value to everybody else. An example use could be like the input method: a,b,c = runtime.broadcast([1,2,3], value) Similarly, broadcast can be used in a conditional if only some subset of parties wants to distribute a value. -- assignedto: mg messages: 310 nosy: jdn, mas, mg status: chatting title: Broadcast type: wish VIFF Issue Tracker trac...@viff.dk http://tracker.viff.dk/issue80 ___ viff-devel mailing list (http://viff.dk/) viff-devel@viff.dk http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk
Re: [viff-devel] [issue80] Broadcast
Citat af Ivan Bjerre Damgård i...@cs.au.dk: It can definitely be useful to have a broadcast method, for instance to complete the implementation of the asynchronous maliciously secure protocol, we will need broadcast. But one needs to be careful about what kind of security we want. There is a whole jungle of protocols, depending on whether it is unconditional or computational security, synchronous or asynchronous network, and what number of players you assume can be corrupt. I think a protocol of Bracha has in fact already been implemented in VIFF Indeed it has. It's located in the active runtime (active.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] [issue80] Broadcast
In the simple case I want to shout out a number to everybody, even somebody who is eavesdropping. -- Janus Den 10/03/2009 kl. 12.23 skrev Ivan Bjerre Damgård: It can definitely be useful to have a broadcast method, for instance to complete the implementation of the asynchronous maliciously secure protocol, we will need broadcast. But one needs to be careful about what kind of security we want. There is a whole jungle of protocols, depending on whether it is unconditional or computational security, synchronous or asynchronous network, and what number of players you assume can be corrupt. I think a protocol of Bracha has in fact already been implemented in VIFF regards, Ivan Quoting Janus Dam Nielsen trac...@viff.dk: New submission from Janus Dam Nielsen janus.niel...@alexandra.dk: I would like to see a broadcast method in the Runtime class. The purpose of the broadcast method should be to distribute a public value among all parties (or some subset of parties). A case: All parties in a computation needs to read a value from standard in, and it is a different value for each party. We want to tell the value to everybody else. An example use could be like the input method: a,b,c = runtime.broadcast([1,2,3], value) Similarly, broadcast can be used in a conditional if only some subset of parties wants to distribute a value. -- assignedto: mg messages: 310 nosy: jdn, mas, mg status: chatting title: Broadcast type: wish VIFF Issue Tracker trac...@viff.dk http://tracker.viff.dk/issue80 ___ viff-devel mailing list (http://viff.dk/) viff-devel@viff.dk http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk ___ viff-devel mailing list (http://viff.dk/) viff-devel@viff.dk http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk ___ viff-devel mailing list (http://viff.dk/) viff-devel@viff.dk http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk
Re: [viff-devel] [issue80] Broadcast
Quoting Janus Dam Nielsen j...@cs.au.dk: In the simple case I want to shout out a number to everybody, even somebody who is eavesdropping. But secrecy of what you shout is not the real problem. The problem is to make sure everyone agrees on what was said. This is not obvious in the case where people may not follow the protocol. For instance, if you want a solution that does not depend on computational assumptions, then if a third or more of the players are corrupt, then there is NO solution. Think of 3 players A,B and C, where A wants to broadcast a message, say 0 or 1. One player may be corrupt. So A is supposed to send a bit b to both B and C. Say B hears 0 from A. He doesn't know if A said the same to C. He can ask C what he heard, but if C says A said 1 to me, there is no way to tell if A or C is lying.. regards, Ivan -- Janus Den 10/03/2009 kl. 12.23 skrev Ivan Bjerre Damgård: It can definitely be useful to have a broadcast method, for instance to complete the implementation of the asynchronous maliciously secure protocol, we will need broadcast. But one needs to be careful about what kind of security we want. There is a whole jungle of protocols, depending on whether it is unconditional or computational security, synchronous or asynchronous network, and what number of players you assume can be corrupt. I think a protocol of Bracha has in fact already been implemented in VIFF regards, Ivan Quoting Janus Dam Nielsen trac...@viff.dk: New submission from Janus Dam Nielsen janus.niel...@alexandra.dk: I would like to see a broadcast method in the Runtime class. The purpose of the broadcast method should be to distribute a public value among all parties (or some subset of parties). A case: All parties in a computation needs to read a value from standard in, and it is a different value for each party. We want to tell the value to everybody else. An example use could be like the input method: a,b,c = runtime.broadcast([1,2,3], value) Similarly, broadcast can be used in a conditional if only some subset of parties wants to distribute a value. -- assignedto: mg messages: 310 nosy: jdn, mas, mg status: chatting title: Broadcast type: wish VIFF Issue Tracker trac...@viff.dk http://tracker.viff.dk/issue80 ___ viff-devel mailing list (http://viff.dk/) viff-devel@viff.dk http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk ___ viff-devel mailing list (http://viff.dk/) viff-devel@viff.dk http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk ___ viff-devel mailing list (http://viff.dk/) viff-devel@viff.dk http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk ___ viff-devel mailing list (http://viff.dk/) viff-devel@viff.dk http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk
Re: [viff-devel] Mystery of the quadratic running time solved?
Hi Ivan, I just wanted to say that I think it would be great if you would implement a version of your proposed two-threaded solution. I do not have a firm grasp of all the programming details, but it does seem that the overall idea is converging, and that some time soon the best way to judge the idea is to go ahead and do it. OK, i will start doing it next Monday. Note that Alexandra is committed to using a non-trivial amount of resources on developing VIFF and related software. Although this may not mean that lots of man-hours are available just now, it might be possible that they could help you. It may also be more efficient that one guy does it in the first iteration, I'll leave this up to you. Since it doesn't seem that complicated to me, I will try it on my own first. But I keep that in mind for the case that I'm wrong. Note that myself, Martin and Jakob will not be at the meeting Thursday. Maybe we should postpone the meeting until next week? Me neither, I'm on holidays until the weekend. Therefore, I would agree to postpone the meeting. Best regards, Marcel ___ viff-devel mailing list (http://viff.dk/) viff-devel@viff.dk http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk
