CCA-Secure Identity-Based Matchmaking Encryption from Standard Assumptions

Identity-based Matchmaking Encryption (IB-ME) is a new form of encryption that enables anonymous communication by specifying identities for both sender and receiver. Its applications in network services put forward higher requirements for the security of IB-ME. According to existing research, the security definition of IB-ME against chosen-plaintext attacks or chosen-ciphertext attacks is still vague. In this paper, we give the first clear definition of CCA-security of IB-ME and propose the first CCA-secure IB-ME scheme under the standard assumptions in the standard model. We first construct a CCA-secure anonymous IBE scheme by combining anonymous hierarchical IBE with CHK CPA-CCA conversion at EUROCRYPT'04. Our proposed IB-ME scheme is a variant of two-level IBE, whose first level is this CCA-secure anonymous IBE, and the second level is a signature derived from this IBE. And its security is proven under standard assumptions and standard model.