Thomas P Jakobsen <thomas....@gmail.com> writes: > 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 way in which we use > pseudo-random secret sharing. In order to maintain security, a new set > of player configuration files has to be generated for each run. > > In some practical settings this turns out to be inconvenient. So we > recently added a changeset (1538:9d4f9551644c) that fixes this. It > means that one no longer has to use fresh configuration files for each > run. Instead, there's now a command line option called computation-id, > e.g. > > python my_viff_program.py --computation-id=42 player-1.ini > > When using runtimes based on pseudo-random secret sharing, like > PassiveRuntime, one can then safely reuse the configuration files as > long as the computation ids are unique. That is, for each run with a > given set of configuration files, the players should agree on a > computation id that has not been used before for that set of > configuration files.
Would it not be fairly easy to let each of the players secret share a random integer, add all the shared numbers, open the result, and use that as the computation ID? That is, automate this so that you don't have to agree on a certain computation ID in advance. -- Martin Geisler aragost Trifork Professional Mercurial support http://aragost.com/mercurial/ _______________________________________________ viff-devel mailing list (http://viff.dk/) email@example.com http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk