QMDS:QKD-based multi-index data secure sharing solution on blockchain

Aiming at the privacy leakage of user data in cloud storage, secure search of encrypted data in cloud storage has become a research hotspot. Most of the current schemes suffer from the problems of assuming secure key distribution channels and considering only one-to-one search mode. In this paper, we propose QMDS, QKD-based(Quantum key distribution-based) multi-index data secure sharing solution on blockchain. To ensure secure key sharing among multiple data owners and data users, we use an actual quantum key distribution network to generate theoretically absolutely secure symmetric quantum keys and encrypt files using quantum keys to achieve secure file storage. To achieve secure sharing of parameters among users, we use zero-knowledge to prove the legal identity of users’ keys. Combined with the Merkle tree, we propose the Merkle XOR tree(MXT). The multi-index structure containing high-priority keywords is extracted in MXT to achieve one-to-many secure retrieval. Meanwhile, we use smart contracts to reliably search and achieve a search time complexity of O(1). Based on the Decisional Diffie-Hellman(DDH) difficult problem assumption, it is proved that the scheme can guarantee the security of keyword index and trapdoor. The correctness and efficiency of the scheme are proved by a large number of actual data experiments.