Inner‐Product Matchmaking Encryption: Bilateral Access Control and Beyond Equality
Qiaohan Chu, Anmin Fu, Haifeng Qian, Jie Chen · IET Information Security · 2023
We present an inner‐product matchmaking encryption (IP‐ME) scheme achieving weak privacy and authenticity in prime‐order groups under symmetric external Diffie–Hellman (SXDH) assumption in the standard model. We further present an IP‐ME with Monotone Span Program Authenticity (IP‐ME with MSP Auth) scheme, where the chosen sender policy is upgraded to MSP, and the scheme also achieves weak privacy and authenticity in prime‐order groups under SXDH assumption in the standard model. Both of the schemes have more expressive functionalities than identity‐based matchmaking encryption (IB‐ME) scheme, and are simpler than Ateniese et al.’s modular ME scheme (Crypto’ 19). But our schemes only achieve a very limited flavor of security, which is reflected in the privacy.