基于ideal-SIS(ideal small integer solution)的一个变种,改进了Damien Stehle的陷门生成算法。利用改进的陷门生成算法对Stehle的选择明文攻击(CPA)安全方案进行了改进,然后结合SWIFFT压缩函数,提出了一种在标准模型下达到适应性选择密文攻击下的不可区分性(IND-CCA2)安全的混合加密方案。在该陷门产生过程中节省了n log q bit的描述位;与原有方案相比,新方案一次加解密的字符长度从n log q bit提高到了m×n log q。基于上述改进,新方案在运行所需的时间和空间效率方面有了很大的提高。
This paper improved the classical generating trapdoor algorithm based on a variant of ideal-SIS( ideal small integer solution) by Damien Stehle. What's more,the new scheme improved a chosen-plaintext attacks security scheme by Damien Stehle. Then,combining with SWIFFT compression functions,it designed an indistinguishable against adaptive chosen-ciphertext attacks secure hybrid encryption scheme in the standard model. In this process,the new scheme required n log q less description bit. It could process string from n log q bit to m × n log q bit in the encryption and decryption processing. There is a huge improvement in key size and speed for these schemes.