Accountable-Authority Identity-Based Matchmaking Encryption and Its Application

Identity-based matchmaking encryption (IB-ME) is a privacy technique that lets two parties securely communicate with mutual access control, but it has a major problem: a central authority can create encryption and decryption keys for any user, enabling key abuse and making it hard to hold anyone accountable. This paper proposes accountable-authority IB-ME (A-IB-ME), which adds accountability by allowing the creator of encryption or decryption keys to be identified if disputes arise, while maintaining the privacy and security features of regular IB-ME.