A Dynamic Type and Identity-Based Proxy Re-Encryption Scheme

Cloud storage is drawing tremendous attention in IT field. In it, an open challenge is to keep the privacy of users' outsourced data and securely share users' data. To address this challenge, proxy re-encryption (PRE) scheme is one of promising method. A dynamic type and identity-based PRE scheme will be proposed. This scheme not only obtains the traditional functions of PRE, but also allows a user to update the original types of his outsourced ciphertexts. Compared with the previous PRE scheme, the new feature makes the proposed PRE scheme more useful in practical applications.