We use cookies to improve your experience with our site.

推广的可调Even-Mansour密码及其应用

Generalized Tweakable Even-Mansour Cipher and Its Applications

  • 摘要: 这篇文章描述了一个推广的可调分组密码HPH,它是基于一个公共的随机置换P和一个带有密钥和调柄策略的泛哈希函数H。令K是一个随机选择的密钥,(t1,t2)是一个有效调柄,x是一个明文,则生成的密文可表示为y=HPH_K((t1,t2),x)。文章使用H-coefficients技术证明了HPH是一个安全的强可调伪随机置换。然后,聚焦HPH在多密钥、相关密钥攻击下的安全性,证明了HPH既实现了多密钥强可调伪随机置换安全又实现了相关密钥强可调伪随机置换安全。最后,将HPH拓展到更广泛的应用环境中。它可以直接应用在认证和认证加密工作模式中。应用到PMAC1方案和OPP方案,提出了改善的认证模式HPMAC和新的认证加密模式OPH,并证明了新提出的方案都实现了多密钥安全和相关密钥安全。

     

    Abstract: This paper describes a generalized tweakable blockcipher HPH (Hash-Permutation-Hash), which is based on a public random permutation P and a family of almost-XOR-universal hash functions H=HKKK as a tweak and key schedule, and defined as y=HP HK((t1, t2), x)=P (xHK(t1)) ⊕ HK(t2), where K is a key randomly chosen from a key space K, (t1, t2) is a tweak chosen from a valid tweak space T, x is a plaintext, and y is a ciphertext. We prove that HPH is a secure strong tweakable pseudorandom permutation (STPRP) by using H-coefficients technique. Then we focus on the security of HPH against multi-key and related-key attacks. We prove that HPH achieves both multi-key STPRP security and related-key STPRP security. HPH can be extended to wide applications. It can be directly applied to authentication and authenticated encryption modes. We apply HPH to PMAC1 and OPP, provide an improved authentication mode HPMAC and a new authenticated encryption mode OPH, and prove that the two modes achieve single-key security, multi-key security, and related-key security.

     

/

返回文章
返回