VIFF, the Virtual Ideal Functionality Framework
News from the changelog:
News from the mailing list:
- Re: softwares for viff 6 weeks ago by Marcel Keller
- Downloads/repository down 7 weeks ago by mikeazo< at >cableone.net
- softwares for viff 7 weeks ago by bharti gupta
- Millionaires example 12 weeks ago by Hongda Xiao
VIFF is a framework which allows you to specify secure multi-party computations in a clean and easy way. Current features include:
- arithmetic with shares from Zp or GF(28).
- secret sharing based on Shamir and pseudo-random secret sharing (PRSS).
- secure addition, multiplication, and exclusive-or of shares.
- comparison of secret shared Zp inputs, with secret Zp or GF(28) output.
- automatic parallel (asynchronous) execution.
- secure communication using SSL.
- cute mascot :-)
VIFF is implemented in Python using Twisted and should run on any platform where Python runs (succesfully tested on Linux, Windows, and Mac OS X). Please see the installation guide for details on the requirements.
VIFF is Free Software, licensed under the GNU LGPL. This means that you can download and use it for free and modify it to suit your needs. You are free to redistribute your modifications as long as you do it together with the modified source. You are allowed to build applications (commercial or not) that use VIFF without having to license them under the LGPL.
Use Cases
VIFF allows you to do secure multi-party computations, in which a number of parties (three or more at the moment) execute a cryptographic protocol to do some joint computation. The computation could be anything, but elections and auctions are good examples of what you would want to do with secure multi-party computations (SMPC or simply MPC if it is implied that the protocol is secure).
Using VIFF your protocol is run without the players revealing anything about their inputs. So three millionaires can determine among themselves who has, say, the most money without revealing how much they are worth to one another. So they all learn who is richest, but nothing else.
The techniques for doing this involves computations on secret shared values, but the programmer can mostly ignore this when using VIFF. Please see the example programs included in the distribution below.
Releases
The latest version of the VIFF source code can be obtained using Mercurial by the command:
hg clone http://hg.viff.dk/viff/
or by browsing the repository online. There you can also subscribe to a RSS or Atom feed with updates.
The repository should be mostly stable (you can check the BuildBot if you are unsure) and a snapshot can be downloaded here:
You can also download a release below:
viff-1.0: tar.bz2, tar.gz, zip, exe, released on December 14th, 2009.
We are happy to declare that we have reached VIFF version 1.0. The current code is useful, flexible and unlikely to change radically. The largest changes since 0.7.1 are summarized below.
The central class named Runtime was renamed to PassiveRuntime. All runtime classes now uses the common method names input and output for providing data to and retrieving data from the computation. A multiparty version of AES was added: it allows parties to encrypt a Shamir secret shared message under a secret shared AES key to obtain a secret shared ciphertext.
See the NEWS file for more details.
viff-0.7.1: tar.bz2, tar.gz, zip, exe, released on October 9th 2008.
A major bug was fixed in the passive multiplication protocol in the case where 2t + 1 != n. Unit tests were updated for Python 2.6.
See the NEWS file for more details.
viff-0.7: tar.bz2, tar.gz, zip, exe, released on September 21st 2008.
PyOpenSSL is now used instead of GnuTLS and this enables secure connections on Windows. The code dealing with starting a player has been made much more robust and players can now be started in any order. Players can now also be reliably shutdown. A new runtime based on homomorphic Paillier encryption supports just two players. Added a new protocol for equality testing with secret shared result.
See the NEWS file for more details.
viff-0.6: tar.bz2, tar.gz, zip, exe, released on May 28th 2008.
The average time for a secure comparison was reduced by 60-70%. Comparisons now work with an actively secure multiplication protocol. A memory leak was fixed. Converted documentation to new Sphinx format.
See the NEWS file for more details.
viff-0.5: tar.bz2, tar.gz, zip, exe, released on April 28th 2008.
Added preliminary support for preprocessing and an efficient multiplication protocol which is secure against active adversaries. The Runtime class has been split into several parts and two new mixin classes provide different comparison protocols. Several coercion problems were fixed. The Runtime.callback method was renamed to Runtime.schedule_callback. VIFF was tested on Python 2.6 and some small problems were fixed. If python-gnutls is unavailable, players now automatically fallback to TCP connections. The installation guide was updated for Windows Vista. A new example program was added and the documentation was updated.
See the NEWS file for more details.
viff-0.4: tar.bz2, tar.gz, zip, exe, released on March 12th 2008.
Implemented a reliable Bracha broadcast which is secure against active adversaries. Shamir sharings, pseudo-random as well as standard, can now be asymmetric which means that only a subset of the parties provide input. The open protocol is now also asymmetric, in the sense that only a subset of the parties receive the opened result. The behavior of field elements in Boolean expressions has been fixed. This means that GF256(0) and GF256(1) now returns GF256(0) instead of GF256(1). Added a modern implementation of the classic Yao millionaires example from 1982 which started this field of research.
See the NEWS file for more details.
viff-0.3: tar.bz2, tar.gz, zip, released on December 27th 2007.
Changes since 0.2: Secure communication between the players were implemented using TLS (the successor to SSL). An included Makefile can generate the needed certificates. The network layer was completely reimplemented, this breaks compatibility with programs written for VIFF version 0.2 or earlier.
viff-0.2: tar.bz2, tar.gz, zip, released on November 14th 2007.
Changes since 0.1.1: Implemented overloaded arithmetic operators, so w = x + y * z now adds and multiplies the three shares as expected. Updated API documentation. Released using a Distutils setup.py script.
viff-0.1.1: tar.bz2, tar.gz, zip, released on October 23rd 2007.
Changes since 0.1: Added API documentation and updated the installation instructions.
viff-0.1: tar.bz2, tar.gz, zip, released on October 16th 2007.
First public release. Implements basic functionality including addition, multiplication, exclusive-or, and comparison of shares. Shares can be made using Shamir sharing or PRSS. Includes a suite of unit tests and example programs.
Please see the installation guide and the VIFF API documentation in addition to the documentation included in the files above.
Contact
Please post your questions and comments on VIFF to the VIFF-devel mailing list. Any question can be sent there — VIFF is still a little rough around the edges, so please ask for help if you cannot get VIFF working! The list is archived locally, at Gmane (where you can read/post over NNTP using a newsreader) and at The Mail Archive.
VIFF is developed by a small development team. Other contributors are very welcome! Please come to the mailing list and talk to us if you want to help in any way.