Daily Shaarli
March 19, 2025
A non-interactive zero-knowledge proof scheme: The prover commits (shuffle+lock) the graph N times: s[0..N]
. He then calculate r=hash(s[0] || s[1] || .. || s[N])
. And then he use the random bits in r
generate N
pseduorandom numbers c[0..N]
. For each i=0..N
, use c[i]
to select a fixed edge in s[i]
and reveal the keys k[i][0]
and k[i][1]
for the two nodes of the edge. The final message consists of s[0..N]
and k[0..N][0..1]
. The verifier is able to use these information to replay the steps to verify the prover's claim.
Another thing I learned from the video is how to "lock" messages cryptographically and allow the verifier to verify any message without revealing the others. First, the prover calculate h[i] = hash(m[i] || nounce[i])
and send h[0..N]
to the verifier. The verify choose any integer t
between 0
and N
and send to prover. The prover will then send back (m[t], nounce[t])
to the verifier that h[t]
is indeed calculated from m[t]
. Here h[t]
is the locked message m[t]
and nounce[t]
is the key.