VIFF is a general framework for doing secure multi-party computations. In a secure multi-party computation several parties jointly compute an agreed function without leaking any information on their inputs. This could be an election where the correct tally is computed without revealing any information on the individual votes. In a protocol with n players, the confidentiality of the inputs is ensured when up to n/2 of the players are corrupted.

VIFF is still under development, but it is nevertheless quite usable and offers the following features:

• secret sharing based on standard Shamir and pseudo-random secret sharing (PRSS).

• arithmetic with shares from Zp or GF(2^8): addition, multiplication, exclusive-or. Some support for actively secure multiplication.

• two comparison protocols which compare secret shared Zp inputs, with secret GF(2^8) or Zp output.

• reliable broadcast, even in the presence of active adversaries.

• computations with any number of players for which an honest majority can be found.

• optional support for encrypted TLS connections between the players.

All operations are automatically scheduled to run in parallel meaning that an operation starts as soon as the operands are ready.

The apps directory contains a number of example applications. They require player configuration files to be generated in advance, use apps/generate-config-files.py for that.

If you have installed the optional PyOpenSSL library, then run apps/generate-certificates.py to generate the keys and certificates for the players.

Finally, execute three players, starting with player 3, then player 2, and finally player 1.