关键词: 公钥加密, 关键字搜索, 代理重加密, 双线性对

Abstract: Public key encryption with keyword search(PEKS) is a practical cryptographic paradigm that enables one to search for the encrypted data without compromising the security of the original data. It provides a promising solution to the encrypted data retrieval issue in public key cryptosystems. As a combination of PEKS and proxy re-encryption(PRE), PRES allows a semi-trusted proxy to simultaneously re-encrypt and search a delegator’s encrypted data. In 2010, Shao et al. firstly presented a proxy re-encryption with keyword search scheme, but their scheme’s security is based on the premise of reducing computing efficiency. This paper solves this problem by presenting a new proxy re-encryption scheme with keyword search without bilinear pairings except the text algorithm. In the random oracle model, it is formally proved that the proposed scheme satisfies the trapdoor indistinguishability security and keyword ciphertext indistinguishability security. Comparison analysis shows that it is efficient and practical.

Key words:  public key encryption, keyword search, proxy re-encryption, bilinear pairing