Network-based evolving quantum secret sharing for general access structures with dynamic membership
Phys. Rev. A 114, 042604 – Published 5 October, 2026
DOI: https://doi.org/10.1103/ryxz-ltn9
Abstract
We introduce RAMPART-X, a quantum secret sharing framework that supports arbitrary dynamic membership under a general monotone access structure while preserving correctness, secrecy, and share invariance over time. Unlike existing approaches that treat dynamic membership, revocation, and access structure enforcement separately, our protocol integrates these features into a unified entanglement-based construction. The share generation mechanism partitions minimally qualified sets and distributes multipartite entangled states, ensuring that previously issued shares remain valid and information theoretically secure throughout system evolution. Reconstruction is achieved without secure classical channels by distributing generalized Bell states along access structure-induced paths, enabling secret recovery via chained entanglement swapping and local quantum operations. Participant revocation is modelled through partial trace, ensuring that newly formed forbidden sets obtain zero information about the secret. We further formalize a distributed dealer architecture in which the dealer generates shares and a combiner coordinates reconstruction, enhancing deployability in decentralized quantum networks. We prove correctness and unconditional security at every time epoch and show that partition independence prevents information leakage under arbitrary access-structure evolution. A proof-of-concept implementation in Python using the Cirq framework validates the protocol construction. To the best of our knowledge, RAMPART-X is the first quantum secret sharing framework to simultaneously support evolving general access structures, dynamic revocation, and entanglement-assisted reconstruction with provable information-theoretic security.
