计算机工程

• 安全技术 • 上一篇    下一篇

理想格上高效的身份基加密方案

魏理豪,艾解清,刘生寒   

  1. (1.中国南方电网有限责任公司 信息化评测重点实验室,广州 510600; 2.广东电网有限责任公司 信息中心,广州 510600)
  • 收稿日期:2015-07-09 出版日期:2016-07-15 发布日期:2016-07-15
  • 作者简介:魏理豪(1978-),男,高级工程师,主研方向为信息安全;艾解清,高级工程师、博士;刘生寒,工程师、硕士。
  • 基金项目:
    广东省自然科学基金资助项目“后量子公钥密码关键技术研究”(S2013020011913)。

Efficient Identity-based Encryption Scheme over Ideal Lattice

WEI Lihao,AI Jieqing,LIU Shenghan   

  1. (1.Key Laboratory of Information Testing,China Southern Power Grid Company Limited,Guangzhou 510600,China; 2.Information Center,Guangdong Power Grid Company Limited,Guangzhou 510600,China)
  • Received:2015-07-09 Online:2016-07-15 Published:2016-07-15

摘要: 基于格的身份基加密方案是近年来密码学研究的热点之一,但是标准格上的身份基方案密钥大且密文扩张率高。为此,基于理想格构造一个密钥较小且密文扩展率较低的身份基加密方案。采用基于NTRU的数字签名与理想格上的对偶加密相结合的方法,在随机预言机模型下证明其安全性。分析结果表明,密钥生成中心的公钥和私钥分别只含有1个和4个环元素,用户的解密密钥只含有2个环元素,密文只含有2个环元素且密文扩张率较小,加密和解密分别只需要4次和2次多项式环上的乘法。与基于传统数论的身份基加密方案相比,提出方法的计算效率更高。

关键词: 理想格, 身份基加密方案, 可证明安全性, 差错学习, 高斯抽样, 对偶加密

Abstract: Recently,Identity-based Encryption(IBE) scheme based on lattices becomes one of the focuses of cryptographic research.But the IBE scheme based on standard lattice have large key size and high ciphertext expansion rate.So based on ideal lattices,this paper presents an efficient identity-based encryption scheme with small key size and low ciphertext expansion rate.The proposed scheme uses a method that combines the NTRU digital signature and the dual encryption based on ideal lattices.It is provably secure in the random oracle model.Analysis results show that the public key and the private key of key generation center contain one ring element and four ring elements respectively.The decryption key of each user is comprised of two ring elements.The ciphertext contains only two ring elements and the ciphertext expansion rate is a small constant.The encryption and decryption require four and two multiplications in the polynomial ring.Hence,the IBE scheme is more computationally efficient than that of traditional number theory based IBE scheme.

Key words: ideal lattice, Identity-based Encryption(IBE) scheme, provable security, learning with errors, Gaussian sampling;dual encryption

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