In cryptography, the anonymous veto network (or AV-net) is a multi-party secure computation protocol to compute the boolean-OR function.
It was first proposed by Feng Hao and Piotr Zieliński in 2006.
[1] This protocol presents an efficient solution to the Dining cryptographers problem.
A related protocol that securely computes a boolean-count function is open vote network (or OV-net).
All participants agree on a group
{\displaystyle \scriptstyle G}
with a generator
{\displaystyle \scriptstyle g}
of prime order
in which the discrete logarithm problem is hard.
For example, a Schnorr group can be used.
For a group of
participants, the protocol executes in two rounds.
Round 1: each participant
selects a random value
and publishes the ephemeral public key
together with a zero-knowledge proof for the proof of the exponent
A detailed description of a method for such proofs is found in RFC 8235.
After this round, each participant computes: Round 2: each participant
publishes
and a zero-knowledge proof for the proof of the exponent
Here, the participants chose
if they want to send a "0" bit (no veto), or a random value if they want to send a "1" bit (veto).
After round 2, each participant computes
If no one vetoed, each will obtain
On the other hand, if one or more participants vetoed, each will have
The protocol is designed by combining random public keys in such a structured way to achieve a vanishing effect.
In this case,
For example, if there are three participants, then
A similar idea, though in a non-public-key context, can be traced back to David Chaum's original solution to the Dining cryptographers problem.