单双钥混合体制的选择密文安全性

Chosen Ciphertext Security of Hybrid Schemes of Symmetric and Asymmetric Encryption

该文主要讨论单双钥混合体制的选择密文安全性IND-CCA的定义和相关结论。在对两种不同用途的单双 钥混合体制及其安全性的研究之后发现它们的IND-CCA定义中允许敌手访问的预言机不同,我们将其统一为:对 只能询问混合体制整体解密机的敌手的安全性,从而统一了混合体制的安全结论,为正确使用混合体制提供了依据。 我们提出了一种混合体制:REACT+,并证明了其IND-CCA安全性。

The definition and related conclusions of chosen ciphertext security IND-CCA (INDistinguishability against adaptive-Chosen Ciphertext Attack) of hybrid encryption of symmetric and asymmetric encryption are discussed. Having studied two kinds of hybrid encryptions of different use and their security definitions, it is found that there is a difference in the oracles. Then the definition of IND-CCA is unified as security for the adversaries can only access the whole decryption oracle of hybrid schemes, which makes the unification of security conclusions of hybrid schemes possible, and supplies the ground for proper use of hybrid schemes. A hybrid scheme called REACT+ has been proposed with its security proof.