格上基于RLWE难题的身份基代理重加密方案

针对目前基于格的身份基代理重加密方案存在的加/解密效率低和密文、密钥尺寸过长的问题,采用原像抽样和对偶加密技术,重新构造了一个基于格的身份基代理重加密方案。该方案采用原像抽样技术提取用户私钥,用对偶加密算法对消息进行加密,利用代理重加密密钥进行重加密,并用用户的私钥进行解密。安全分析表明,在标准模型下,基于ring learning with errors困难假设,该方案满足IND-aID-CPA安全。效率分析表明,该方案可以有效缩短密文和密钥尺寸,提高加/解密效率。

Identity-based proxy re-encryption scheme based on RLWE problem

Aiming at the problems of low encryption and decryption efficiency and too long ciphertext and key size of the current lattice-based identity-based proxy re-encryption scheme,this paper used the pre-image sampling and dual encryption technology to reconstruct a lattice-based identity-based proxy re-encryption scheme.The scheme utilized the pre-image sampling technique and dual encryption algorithm to extract the user’s private key and encrypt the message respectively,then used the agent re-encryption key and the user’s private key to re-encrypt and decrypt separately.Security analysis shows that under the standard model,based on the difficult assumption of ring learning with errors,this scheme meets IND-aID-CPA security.Efficiency analysis shows that proposed scheme can effectively shorten the ciphertext and key size,and improve the encryption and decryption efficiency.