Proxy re-encryption is a cryptographic primitive developed to delegate the decryption right from one party (the delegator) to another (the delegatee). So far, research efforts have only been devoted to the intra-domain setting, where the delegator and the delegatee are registered in the same domain. In this paper, we investigate the proxy re-encryption in the inter-domain setting, where the delegator and the delegatee are from different domains, and focus on the identity-based case. We analyze the trust relationships and possible threats to the plaintext privacy, and provide rigorous security definitions. We propose a new inter-domain identity-based proxy re-encryption scheme and prove its security in our security model. An interesting property of the proposed scheme is that, to achieve the chosen plaintext security for the delegator, the delegatee's IBE only needs to be one-way.
Tang et al. in Reference REF presented an inter-domain identity-based proxy re-encryption (IBPRE) scheme, which achieves secure data sharing between users in different domains.
Inter-domain Identity-based Proxy Re-encryption
Inscrypt
Computer Science