Citat af Kyung-Wook Hwang <kwhw...@ee.columbia.edu>:
Hello, This is Kyung Hwang from Columbia University again. I have another question. Does Viff always need at least 3 participants? It seems to me it does.
That depends on the runtime you use. If you are using the default passive security runtime, this is based on Shamir secret-sharing. Therefore there must be at least 3 parties, and the threshold will always be < n/2.
There is in fact also a two-party runtime based on the Paillier cryptosystem. You can check it out if you want, it's in paillier.py.
But basically you have to select a runtime that gives you what you want. If you want 2-party MPC, you can't use the Shamir sharing based runtime.
I modified "beginner.py" for two players because that file was simplest to modify, but when I ran the two players, I got the following errors: kwhw...@kwhwang-sim1:~/viff-1.0/apps$ python beginner2.py player-2.ini 20 --no-ssl Seeding random generator with random seed 3781 /home/kwhwang/opt/lib/python/viff/prss.py:43: DeprecationWarning: the sha module is deprecated; use the hashlib module instead import sha I am player 2 and will input 20 Not using SSL Listening on port 9002 #### Starting reactor ### ---------------------------------------------------------------- Program started Error: [Failure instance: Traceback: <type 'exceptions.KeyError'>: 3 /home/kwhwang/opt/lib/python/viff/runtime.py:317:stringReceived /home/kwhwang/opt/lib/python/viff/runtime.py:456:identify_peer /usr/lib/python2.6/dist-packages/twisted/internet/defer.py:280:callback /usr/lib/python2.6/dist-packages/twisted/internet/defer.py:354:_startRunCallbacks --- <exception caught here> --- /usr/lib/python2.6/dist-packages/twisted/internet/defer.py:371:_runCallbacks beginner2.py:69:protocol /home/kwhwang/opt/lib/python/viff/passive.py:493:input /home/kwhwang/opt/lib/python/viff/passive.py:550:shamir_share /home/kwhwang/opt/lib/python/viff/runtime.py:785:_expect_share /home/kwhwang/opt/lib/python/viff/runtime.py:749:_expect_data /home/kwhwang/opt/lib/python/viff/runtime.py:754:_expect_data_with_pc
As you can see, it's using shamir_share. Shamir sharing requires at least 3 players.
I also modified equality.py for two players to see if it works for only two players because that file actually compared only two players' inputs but not the third player's so that file essentially needs two players. But it gaves errors too with two players. I think Viff only works with at least three players. Am I correct?
Same as above :) Regards, Mikkel Krøigård _______________________________________________ viff-devel mailing list (http://viff.dk/) firstname.lastname@example.org http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk