[viff-devel] Confusing behaviour?

2009-03-23 Thread Thomas P Jakobsen
Hi all, When I execute the attached VIFF protocol on three servers I would expect all three to ask me to press enter. When all three servers have done that, I would expect the computation of c to start and that the servers will eventually finish. I've run the protocol several times on Linux and

Re: [viff-devel] Confusing behaviour?

2009-03-24 Thread Thomas P Jakobsen
Thanks for the reply. However, your problem probably could be fixed by synchronizing before blocking: sync = runtime.synchronize() sync.schedule_callback(blocking_code()) Yes, I was thinking the same thing. Another way of avoiding the problem is to place initial local computations outside

Re: [viff-devel] Confusing behaviour?

2009-03-26 Thread Thomas P Jakobsen
Thanks for the clarification. I erroneously assumed that blocking stuff was ok in Twisted as long as it happens before any communication. But it makes good sense that one should avoid this anywhere in a Twisted program. Regards, Thomas 2009/3/26 Martin Geisler m...@daimi.au.dk: Thomas P

[viff-devel] A bug in VIFF?

2009-06-12 Thread Thomas P Jakobsen
Hi VIFF guys, I've implemented a VIFF application involving two binary searches. A typical trace from one of the players during excecution looks like this: search for p1 search for p1: [-1, 4000] search for p2 search for p2: [0, 4001] search for p1: [-1, 4000] search for p2: [0, 4001] search for

Re: [viff-devel] A bug in VIFF?

2009-06-16 Thread Thomas P Jakobsen
Problem seems to be fixed. I used addCallback several places where I should instead have used schedule_callback. The new changes to VIFF somehow triggered this bug. Best regards, Thomas ___ viff-devel mailing list (http://viff.dk/) viff-devel@viff.dk

Re: [viff-devel] A java implementation of VIFF

2009-08-18 Thread Thomas P Jakobsen
Nice work! It would be interesting to see how it performs compared to VIFF. Best regards, Thomas ___ viff-devel mailing list (http://viff.dk/) viff-devel@viff.dk http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk

Re: [viff-devel] Query from the University of Surrey

2010-02-23 Thread Thomas P Jakobsen
When I run the Millionaires example (again with --no-ssl option)  with the Path set to point to Python 2.6.4, I get the following error message. Traceback (most recent call last):  File generate-config-files.py, line 57, in module    from viff.config import generate_configs ImportError:

[viff-devel] Fairplay -- VIFF compiler

2010-07-06 Thread Thomas P Jakobsen
Hi all, In the CACE project (http://www.cace-project.eu) we've just created a compiler that can translate MPC programs written for FairplayMP to VIFF programs. VIFF and Fairplay each have their benefits. If you write your MPC program in the Fairplay language, you can now freely decide which MPC

Re: [viff-devel] VIFF and random numbers

2010-07-06 Thread Thomas P Jakobsen
to use the wrong kind of PRG, it should be fixed as soon as possible. But do we know that os.urandom will be OK on any platform, or is this OS -dependent at the end of the day? - Ivan On 06/07/2010, at 15.22, Thomas P Jakobsen wrote: VIFF itself as well as most protocols implemented in VIFF uses

Re: [viff-devel] VIFF and random numbers

2010-07-06 Thread Thomas P Jakobsen
I agree that tests should be reproducible. But it is also very important to use a cryptographically secure PRNG. I don't know whether these two requirements can be satisfied by the same number generator. If not, the best solution is to have two modes of operation: - A test mode where the

[viff-devel] Securely running the same VIFF program multiple times

2010-08-12 Thread Thomas P Jakobsen
Hi all, As you may or may not know, running the same VIFF program more than once using the same set of player configuration files is insecure when the runtime relies on pseudo-random secret sharing. This is the case for e.g. the PassiveRuntime. This is not a bug, but rather a consequence of the

[viff-devel] [issue83] Use cryptographically secure prng

2010-08-12 Thread Thomas P Jakobsen
New submission from Thomas P Jakobsen t...@cs.au.dk: Currently, VIFF uses a pseudo-random number generator with weak security properties (Mersenne-Twister). We should rather use a cryptographically strong prng. See discussion at http://article.gmane.org/gmane.comp.cryptography.viff.devel/834