基于格的公钥加密与证书基加密

Public-key encryption and certificate-based encryption from lattice

证书基加密(CBE)结合了基于身份加密和公钥基础设施的各自优点,然而基于传统数学假设的CBE不能有效抵御量子算法的攻击.为此构建了一个基于格的CBE方案,可有效抵御量子算法的攻击.首先构建出一个基于格的公钥加密(PKE)方案,之后利用该PKE构建出基于格的CBE方案.该方案可被规约为格上的学习误差(LWE)问题,因此得到的CBE为随机不可区分选择明文攻击安全的.该方案是目前为止已知的第一个基于格的CBE方案.

Certificate-based encryption （CBE） combines the advantages of identity-based en- cryption and that of public key infrastructure. However, CBE based on traditional mathematical assumptions cannot defeat quantum attacks. This paper aims at constructing a lattice-based CBE which is post-quantum： First constructed a lattice-based public key encryption （PKE） ; then used this PKE to construct a lattice-based CBE. Finally, it was proved that the ciphertexts generated by our CBE are indistinguishable from random against chosen-plaintext attacks （namely, INDr- CBE-CPA secure） by assuming that the learning with errors （LWE） problem is hard. This scheme is the first known lattice-based CBE so far.