Chosen Ciphertext Secure Keyed-Homomorphic Public-Key Encryption
Chosen Ciphertext Secure Keyed-Homomorphic Public-Key Encryption
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DOI：
10.1007/978-3-642-36362-7_3
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发表时间：
2013-02
期刊：
影响因子：
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通讯作者：
K. Emura;Goichiro Hanaoka;G. Ohtake;Takahiro Matsuda;Shota Yamada
中科院分区：
文献类型：
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作者：
K. Emura;Goichiro Hanaoka;G. Ohtake;Takahiro Matsuda;Shota Yamada
在同态加密方案中，任何人都可以执行同态操作，因此很难管理何时、何地和由谁执行这些操作。此外，任何人都可以自由地执行运算的性质不可避免地意味着密文是可塑性的，众所周知，自适应选择密文(CCA)安全性和同态性质永远不可能同时实现。本文证明了在能够对加密数据进行同态运算的用户(S)必须被控制/限制的情况下，CCA的安全性和同态性质是可以同时处理的，并提出了一种新的同态公钥加密的概念，我们称之为密钥同态公钥加密。通过引入用于同态运算的密钥，我们可以控制允许谁执行同态运算。为了构造KH-PKE方案，我们引入了同态过渡泛哈希族的概念，并通过哈希证明系统提出了一些KH-PKE方案。我们还给出了一个基于DDH假设的KH-PKE的实际构造。对于ℓ位安全性，我们的基于DDH的方案只产生比Cramer-Shoup PKE方案长ℓ位的密文长度。
In homomorphic encryption schemes, anyone can perform homomorphic operations, and therefore, it is difficult to manage when, where and by whom they are performed. In addition, the property that anyone can ‘‘freely” perform the operation inevitably means that ciphertexts are malleable, and it is well-known that adaptive chosen ciphertext (CCA) security and the homomorphic property can never be achieved simultaneously. In this paper, we show that CCA security and the homomorphic property can be simultaneously handled in situations that the user(s) who can perform homomorphic operations on encrypted data should be controlled/limited, and propose a new concept of homomorphic public-key encryption, which we callkeyed-homomorphic public-key encryption(KH-PKE). By introducing a secret key for homomorphic operations, we can control who is allowed to perform the homomorphic operation. To construct KH-PKE schemes, we introduce a new concept, ahomomorphic transitional universal hash family, and present a number of KH-PKE schemes through hash proof systems. We also present a practical construction of KH-PKE from the DDH assumption. For ℓ-bit security, our DDH-based scheme yields only ℓ-bit longer ciphertext size than that of the Cramer-Shoup PKE scheme.