Decentralized Multi-authority Accurate Matchmaking Encryption Scheme for Mobile Social Networks

Mobile social networks (MSNs) are integral to the digital era, but the current architectures raise fundamental challenges to user privacy and security. First, these systems rely on a trusted authority, which causes the single point of failure and raises concerns about data leakage. Second, there is a lack of cryptographic mechanisms to enforce bilateral access control, which ensures mutual consent communication by both senders and receivers. Therefore, it's necessary to design a system to eliminate single-point trust and accurate consent-based matchmaking access control between users. To address these issues, we propose a decentralized multi-authority identity-based matchmaking encryption (DMA-IBME) scheme, including its formal syntax and security definitions. This primitive enables bilateral access control, which ensures both data privacy and user authenticity. Moreover, we formally prove the security of our scheme in the random oracle model under the standard bilinear Diffie-Hellman (BDH) assumption. Performance evaluation demonstrates the efficiency of our scheme. Compared to existing works, our construction reduces the setup time by approximately 50% and the encryption key generation time by 30%. Furthermore, the storage costs for public parameters, encryption keys, and ciphertexts are reduced by approximately 30%, 30%, and 88%, respectively.