pub fn prove_threshold(
value: u64,
threshold: u64,
) -> Result<PredicateProof, String>Expand description
Prove, in zero knowledge, that a private value satisfies value >= threshold.
Returns a PredicateProof (compressed Groth16 proof + verifying key). Fails
with an Err if value < threshold — there is no satisfying witness, so the
honest prover cannot construct a proof (this is the soundness property: a
false statement is unprovable, not merely unverifiable).