The security and performance of Mixnets depends on the trustworthiness of the
Mixnodes in the network. The challenge is to limit the adversary’s influence on
which Mixnodes operate in the network. A trusted party (such as the Mixnet
operator) may ensure this, however, it is a single point of failure in the
event of corruption or coercion. Therefore, we study the problem of how to
select a subset of Mixnodes in a distributed way for Mixnet construction. We
present VeraSel, a scheme that enables Mixnodes to be chosen according to their
weights in a distributed, unbiased, and verifiable fashion using Verifiable
Random Functions (VRFs). It is shown that VeraSel enables any party to learn
and verify which nodes has been selected based on the commitments and proofs
generated by each Mixnode with VRF.
