Quantum Multi-Party Computation (QMPC) for Enhanced Blockchain Consensus

Fault-tolerant quantum computers threaten blockchains at both the signature layer (e.g., ECDSA) and the consensus layer (e.g., Grover-accelerated hash puzzles). Most 'post-quantum' proposals replace vulnerable primitives with Post Quantum Cryptography (PQC), leaving the consensus logic itself classical and quantum-accelerable. We present a quantumnative consensus protocol that uses multipartite entanglement to enforce core security properties at the level of physics. A post-quantum digital signature scheme is assumed only as a thin authentication layer for classical messages; the main logic resides in a Quantum Multi-Party Computation (QMPC) layer. Using distributed GHZ states and a sum-of-columns construction, nodes generate an information-theoretically secure random beacon and deterministically elect a round leader, after passing disturbance checks that detect tampering with high confidence. The beacon supports a standard BFT-style commit phase, yielding agreement, validity, and termination against a Quantum Polynomial Time (QPT) adversary corrupting fewer than one-third of the nodes. Quantum-circuit simulations of intercept-resend attacks validate the disturbance-detection mechanism and corroborate our theoretical analysis.