Using lattice basis delegation in a fixed dimension, we propose an efficient lattice-based hierarchical identity based encryption（HIBE） scheme in the standard model whose public key size is only（dm^2＋ mn） log q b...Using lattice basis delegation in a fixed dimension, we propose an efficient lattice-based hierarchical identity based encryption（HIBE） scheme in the standard model whose public key size is only（dm^2＋ mn） log q bits and whose message-ciphertext expansion factor is only log q, where d is the maximum hierarchical depth and（n, m, q）are public parameters. In our construction, a novel public key assignment rule is used to averagely assign one random and public matrix to two identity bits, which implies that d random public matrices are enough to build the proposed HIBE scheme in the standard model, compared with the case in which 2d such public matrices are needed in the scheme proposed at Crypto 2010 whose public key size is（2dm^2＋ mn ＋ m） log q. To reduce the message-ciphertext expansion factor of the proposed scheme to log q, the encryption algorithm of this scheme is built based on Gentry＇s encryption scheme, by which m^2 bits of plaintext are encrypted into m^2 log q bits of ciphertext by a one time encryption operation. Hence, the presented scheme has some advantages with respect to not only the public key size but also the message-ciphertext expansion factor. Based on the hardness of the learning with errors problem, we demonstrate that the scheme is secure under selective identity and chosen plaintext attacks.展开更多
Hierarchical Identity-Based Broadcast Encryption （HIBBE） organizes users into a tree-like structure, and it allows users to delegate their decryption ability to subordinates and enable encryption to any subset of us...Hierarchical Identity-Based Broadcast Encryption （HIBBE） organizes users into a tree-like structure, and it allows users to delegate their decryption ability to subordinates and enable encryption to any subset of users while only intended users can decrypt. However, current HIBBE schemes do not support efficient revocation of private keys. Here, a new primitive called Revocable Hierarchical Identity-Based Broadcast Encryption （RHIBBE） is formalized that allows revocation of the HIBBE. Ciphertext indistinguishability is defined against the selectively Bounded Revocable Identity-Vector-Set and Chosen-Plaintext Attack （IND-sBRIVS-CPA）. An IND-sBRIVS-CPA secure RHIBBE scheme is constructed with efficient revocation on prime-order bilinear groups. The unbounded version of the scheme is also shown to be secure but a little weaker than the former under the decisional n-Weak Bilinear Diffie-Hellman inversion assumption.展开更多
According to the relation of an attribute set and its subset,the author presents a hierarchical attribute-based encryption scheme in which a secret key is associated with an attribute set.A user can delegate the priva...According to the relation of an attribute set and its subset,the author presents a hierarchical attribute-based encryption scheme in which a secret key is associated with an attribute set.A user can delegate the private key corresponding to any subset of an attribute set while he has the private key corresponding to the attribute set.Moreover,the size of the ciphertext is constant,but the size of private key is linear with the order of the attribute set in the hierarchical attribute-based encryption scheme.Lastly,we can also prove that this encryption scheme meets the security of IND-sSETCPA in the standard model.展开更多
结合属性树结构及分层IBE(Identity Based Encryption)加密机制,提出了一种基于属性树结构的分层隐藏证书模型。该模型使用属性树来组织敏感信息,并采用分层的隐藏证书来携带并传递双方交换的证书、访问控制策略、资源等信息,在保护了...结合属性树结构及分层IBE(Identity Based Encryption)加密机制,提出了一种基于属性树结构的分层隐藏证书模型。该模型使用属性树来组织敏感信息,并采用分层的隐藏证书来携带并传递双方交换的证书、访问控制策略、资源等信息,在保护了上述敏感信息的前提下,将属性从单一原子扩展为属性树,解决了基于属性访问控制策略所固有的网络开销大、证书往来过于频繁等缺点,同时也提高了隐藏证书系统的可用性和可扩展性。展开更多
针对传统的身份基全同态加密(IBFHE)方案无法对不同身份标识(ID)下的密文进行同态运算的问题,提出一个基于误差学习(LWE)问题的分层身份基多用户全同态加密方案。该方案利用Clear等(CLEAR M, McGOLDRICK C. Multi-identity and multi-ke...针对传统的身份基全同态加密(IBFHE)方案无法对不同身份标识(ID)下的密文进行同态运算的问题,提出一个基于误差学习(LWE)问题的分层身份基多用户全同态加密方案。该方案利用Clear等(CLEAR M, McGOLDRICK C. Multi-identity and multi-key leveled FHE from learning with errors. Proceedings of the 2015 Annual Cryptology Conference, LNCS 9216. Berlin:Springer, 2015:630-656)在2015年提出的身份基多用户全同态加密方案(方案)的转化机制,结合Cash等(CASH D, HOFHEINZ D, KILTZ E, et al. Bonsai trees, or how to delegate a lattice basis. Proceedings of the 2010 Annual International Conference on the Theory and Applications of Cryptographic Techniques, LNCS 6110. Berlin:Springer, 2010:523-552)在2010年提出的身份基加密(IBE)方案■方案),实现了不同身份标识下的密文同态运算,应用前景更加广阔,在随机预言机模型下为基于身份匿名的选择明文攻击下的不可区分性(IND-ID-CPA)安全。与方案相比,该方案在公钥规模、私钥规模、密文尺寸、分层性质和密钥更新周期方面都具有优势。展开更多
基金Project supported by the National Natural Science Foundation of China（Nos.61303198,61471409,61472470,and 61402112） the Natural Science Foundation of Shandong Province,China（No.ZR2013FQ031）
文摘Using lattice basis delegation in a fixed dimension, we propose an efficient lattice-based hierarchical identity based encryption（HIBE） scheme in the standard model whose public key size is only（dm^2＋ mn） log q bits and whose message-ciphertext expansion factor is only log q, where d is the maximum hierarchical depth and（n, m, q）are public parameters. In our construction, a novel public key assignment rule is used to averagely assign one random and public matrix to two identity bits, which implies that d random public matrices are enough to build the proposed HIBE scheme in the standard model, compared with the case in which 2d such public matrices are needed in the scheme proposed at Crypto 2010 whose public key size is（2dm^2＋ mn ＋ m） log q. To reduce the message-ciphertext expansion factor of the proposed scheme to log q, the encryption algorithm of this scheme is built based on Gentry＇s encryption scheme, by which m^2 bits of plaintext are encrypted into m^2 log q bits of ciphertext by a one time encryption operation. Hence, the presented scheme has some advantages with respect to not only the public key size but also the message-ciphertext expansion factor. Based on the hardness of the learning with errors problem, we demonstrate that the scheme is secure under selective identity and chosen plaintext attacks.
基金supported by the National Key Research and Development Program of China (No. 2017YFB0802502)the National Natural Science Foundation of China (Nos. 61672083, 61370190, 61532021, 61472429, 61402029, 61702028, and 61571024)+3 种基金the National Cryptography Development Fund (No. MMJJ20170106)the Planning Fund Project of Ministry of Education (No. 12YJAZH136)the Beijing Natural Science Foundation (No. 4132056)the Fund of the State Key Laboratory of Information Security, the Institute of Information Engineering, and the Chinese Academy of Sciences (No. 2017-MS-02)
文摘Hierarchical Identity-Based Broadcast Encryption （HIBBE） organizes users into a tree-like structure, and it allows users to delegate their decryption ability to subordinates and enable encryption to any subset of users while only intended users can decrypt. However, current HIBBE schemes do not support efficient revocation of private keys. Here, a new primitive called Revocable Hierarchical Identity-Based Broadcast Encryption （RHIBBE） is formalized that allows revocation of the HIBBE. Ciphertext indistinguishability is defined against the selectively Bounded Revocable Identity-Vector-Set and Chosen-Plaintext Attack （IND-sBRIVS-CPA）. An IND-sBRIVS-CPA secure RHIBBE scheme is constructed with efficient revocation on prime-order bilinear groups. The unbounded version of the scheme is also shown to be secure but a little weaker than the former under the decisional n-Weak Bilinear Diffie-Hellman inversion assumption.
基金Supported by the National Natural Science Foundation of China(60903175,60703048)the Natural Science Foundation of Hubei Province(2009CBD307,2008CDB352)
文摘According to the relation of an attribute set and its subset,the author presents a hierarchical attribute-based encryption scheme in which a secret key is associated with an attribute set.A user can delegate the private key corresponding to any subset of an attribute set while he has the private key corresponding to the attribute set.Moreover,the size of the ciphertext is constant,but the size of private key is linear with the order of the attribute set in the hierarchical attribute-based encryption scheme.Lastly,we can also prove that this encryption scheme meets the security of IND-sSETCPA in the standard model.
文摘结合属性树结构及分层IBE(Identity Based Encryption)加密机制,提出了一种基于属性树结构的分层隐藏证书模型。该模型使用属性树来组织敏感信息,并采用分层的隐藏证书来携带并传递双方交换的证书、访问控制策略、资源等信息,在保护了上述敏感信息的前提下,将属性从单一原子扩展为属性树,解决了基于属性访问控制策略所固有的网络开销大、证书往来过于频繁等缺点,同时也提高了隐藏证书系统的可用性和可扩展性。
文摘针对传统的身份基全同态加密(IBFHE)方案无法对不同身份标识(ID)下的密文进行同态运算的问题,提出一个基于误差学习(LWE)问题的分层身份基多用户全同态加密方案。该方案利用Clear等(CLEAR M, McGOLDRICK C. Multi-identity and multi-key leveled FHE from learning with errors. Proceedings of the 2015 Annual Cryptology Conference, LNCS 9216. Berlin:Springer, 2015:630-656)在2015年提出的身份基多用户全同态加密方案(方案)的转化机制,结合Cash等(CASH D, HOFHEINZ D, KILTZ E, et al. Bonsai trees, or how to delegate a lattice basis. Proceedings of the 2010 Annual International Conference on the Theory and Applications of Cryptographic Techniques, LNCS 6110. Berlin:Springer, 2010:523-552)在2010年提出的身份基加密(IBE)方案■方案),实现了不同身份标识下的密文同态运算,应用前景更加广阔,在随机预言机模型下为基于身份匿名的选择明文攻击下的不可区分性(IND-ID-CPA)安全。与方案相比,该方案在公钥规模、私钥规模、密文尺寸、分层性质和密钥更新周期方面都具有优势。
