We address the cryptographic topic of proxy re-encryption （PRE）, which is a special public-key cryptosystem. A PRE scheme allows a special entity, known as the proxy, to transform a message encrypted with the public...We address the cryptographic topic of proxy re-encryption （PRE）, which is a special public-key cryptosystem. A PRE scheme allows a special entity, known as the proxy, to transform a message encrypted with the public key of a delegator （say Alice）, into a new ciphertext that is protected under the public key of a delegatee （say Bob）, and thus the same message can then be recovered with Bob＇s private key. In this paper, in the identity-based setting, we first investigate the relationship between so called mediated encryption and unidirectional PRE. We provide a general framework which converts any secure identity-based unidirectional PRE scheme into a secure identity-based mediated encryption scheme, and vice versa. Concerning the security for unidirectional PRE schemes, Ateniese et al. previously suggested an important property known as the master secret security, which requires that the coalition of the proxy and Bob cannot expose Alice＇s private key. In this paper, we extend the notion to the identity-based setting, and present an identity-based unidirectional PRE scheme, which not only is provably secure against the chosen eiphertext attack in the standard model but also achieves the master secret security at the same time.展开更多
Certificateless public key cryptography （CL- PKC） can solve the problems of certificate management in a public key infrastructure （PKI） and of key escrows in identity-based public key cryptography （ID-PKC）. In C...Certificateless public key cryptography （CL- PKC） can solve the problems of certificate management in a public key infrastructure （PKI） and of key escrows in identity-based public key cryptography （ID-PKC）. In CL- PKC, the key generation center （KGC） does not know the private keys of all users, and their public keys need not be cer- tificated by certification authority （CA）. At present, however, most certificateless encryption schemes are based on large in- teger factorization and discrete logarithms that are not secure in a quantum environment and the computation complexity is high. To solve these problems, we propose a new certificate- less encryption scheme based on lattices, more precisely, us- ing the hardness of the learning with errors （LWE） problem. Compared with schemes based on large integer factoriza- tion and discrete logarithms, the most operations are matrix- vector multiplication and inner products in our scheme, our approach has lower computation complexity. Our scheme can be proven to be indistinguishability chosen ciphertext attacks （IND-CPA） secure in the random oracle model.展开更多
Remote authentication is a safe and verifiable mechanism.In the Internet of Things (loT),remote hosts need to verify the legitimacy of identity of terminal devices.However,embedded devices can hardly afford sufficient...Remote authentication is a safe and verifiable mechanism.In the Internet of Things (loT),remote hosts need to verify the legitimacy of identity of terminal devices.However,embedded devices can hardly afford sufficient resources for the necessary trusted hardware components.Software authentication with no hardware guarantee is generally vulnerable to various network attacks.In this paper,we propose a lightweight remote verification protocol.The protocol utilizes the unique response returned by Physical Unclonable Function (PUF) as legitimate identity basis of the terminal devices and uses quadratic residues to encrypt the PUF authentication process to perform a double identity verification scheme.Our scheme is secure against middleman attacks on the attestation response by preventing conspiracy attacks from forgery authentication.展开更多
A recent proposal by Adams integrates the digital credentials (DC) technology of Brands with the identity-based encryption (IBE) technology of Boneh and Franklin to create an IBE scheme that demonstrably enhances priv...A recent proposal by Adams integrates the digital credentials (DC) technology of Brands with the identity-based encryption (IBE) technology of Boneh and Franklin to create an IBE scheme that demonstrably enhances privacy for users. We refer to this scheme as a privacy-preserving identity-based encryption (PP-IBE) construction. In this paper, we discuss the concrete implementation considerations for PP-IBE and provide a detailed instantiation (based on q-torsion groups in supersingular elliptic curves) that may be useful both for proof-of-concept purposes and for pedagogical purposes.展开更多
Identity-Based Encryption (IBE) has seen limited adoption, largely due to the absolute trust that must be placed in the private key generator (PKG)—an authority that computes the private keys for all the users in the...Identity-Based Encryption (IBE) has seen limited adoption, largely due to the absolute trust that must be placed in the private key generator (PKG)—an authority that computes the private keys for all the users in the environment. Several constructions have been proposed to reduce the trust required in the PKG (and thus preserve the privacy of users), but these have generally relied on unrealistic assumptions regarding non-collusion between various entities in the system. Unfortunately, these constructions have not significantly improved IBE adoption rates in real-world environments. In this paper, we present a construction that reduces trust in the PKG without unrealistic non-collusion assumptions. We achieve this by incorporating a novel combination of digital credential technology and bilinear maps, and making use of multiple randomly-chosen entities to complete certain tasks. The main result and primary contribution of this paper are a thorough security analysis of this proposed construction, examining the various entity types, attacker models, and collusion opportunities in this environment. We show that this construction can prevent, or at least mitigate, all considered attacks. We conclude that our construction appears to be effective in preserving user privacy and we hope that this construction and its security analysis will encourage greater use of IBE in real-world environments.展开更多
为使移动设备更加方便快捷地解密存储于云端的外包数据,根据基于身份的广播加密(IBBE)系统和基于身份的加密(IBE)系统,使用Green等提出的解密外包的技术(GREEN M,HOHENBERGER S,WATERS B.Outsourcing the decryption of ABE ciphertexts...为使移动设备更加方便快捷地解密存储于云端的外包数据,根据基于身份的广播加密(IBBE)系统和基于身份的加密(IBE)系统,使用Green等提出的解密外包的技术(GREEN M,HOHENBERGER S,WATERS B.Outsourcing the decryption of ABE ciphertexts.Proceedings of the 20th USENIX Conference on Security.Berkeley:USENIX Association,2011:34),提出一种改进的非对称跨加密系统的代理重加密(MACPRE)方案。该方案更适合计算能力有限的移动设备安全共享云端数据。移动用户在解密重加密后的数据时,运行一次指数运算和一次配对运算便可以将明文恢复,大大提高了移动用户解密的效率,降低了移动用户的能耗。该方案的安全性可以归约到底层的IBE方案和IBBE方案的安全性。理论分析和实验结果表明,该方案使得移动设备花费较少的时间便可以将存储在云端的数据解密,缓解了移动设备计算能力的不足,实用性较强。展开更多
基金partially supported by the National Natural Science Foundation of China under Grant No.60873229Shanghai Rising-Star Program under Grant No.09QA1403000the Office of Research,Singapore Management University
文摘We address the cryptographic topic of proxy re-encryption （PRE）, which is a special public-key cryptosystem. A PRE scheme allows a special entity, known as the proxy, to transform a message encrypted with the public key of a delegator （say Alice）, into a new ciphertext that is protected under the public key of a delegatee （say Bob）, and thus the same message can then be recovered with Bob＇s private key. In this paper, in the identity-based setting, we first investigate the relationship between so called mediated encryption and unidirectional PRE. We provide a general framework which converts any secure identity-based unidirectional PRE scheme into a secure identity-based mediated encryption scheme, and vice versa. Concerning the security for unidirectional PRE schemes, Ateniese et al. previously suggested an important property known as the master secret security, which requires that the coalition of the proxy and Bob cannot expose Alice＇s private key. In this paper, we extend the notion to the identity-based setting, and present an identity-based unidirectional PRE scheme, which not only is provably secure against the chosen eiphertext attack in the standard model but also achieves the master secret security at the same time.
基金This work was supported by the National Natural Science Foundations of China （Grant Nos. 61173151, 61173152 and 61100229） and Huawei Technologies Co., Ltd., （YBCB2011116）.
文摘Certificateless public key cryptography （CL- PKC） can solve the problems of certificate management in a public key infrastructure （PKI） and of key escrows in identity-based public key cryptography （ID-PKC）. In CL- PKC, the key generation center （KGC） does not know the private keys of all users, and their public keys need not be cer- tificated by certification authority （CA）. At present, however, most certificateless encryption schemes are based on large in- teger factorization and discrete logarithms that are not secure in a quantum environment and the computation complexity is high. To solve these problems, we propose a new certificate- less encryption scheme based on lattices, more precisely, us- ing the hardness of the learning with errors （LWE） problem. Compared with schemes based on large integer factoriza- tion and discrete logarithms, the most operations are matrix- vector multiplication and inner products in our scheme, our approach has lower computation complexity. Our scheme can be proven to be indistinguishability chosen ciphertext attacks （IND-CPA） secure in the random oracle model.
基金supported in part by the National Basic Research Program of China(973 Program)(No.2014CB340600)in part by the Wuhan Frontier Program of Application Foundation(No.2018010401011295)。
文摘Remote authentication is a safe and verifiable mechanism.In the Internet of Things (loT),remote hosts need to verify the legitimacy of identity of terminal devices.However,embedded devices can hardly afford sufficient resources for the necessary trusted hardware components.Software authentication with no hardware guarantee is generally vulnerable to various network attacks.In this paper,we propose a lightweight remote verification protocol.The protocol utilizes the unique response returned by Physical Unclonable Function (PUF) as legitimate identity basis of the terminal devices and uses quadratic residues to encrypt the PUF authentication process to perform a double identity verification scheme.Our scheme is secure against middleman attacks on the attestation response by preventing conspiracy attacks from forgery authentication.
文摘A recent proposal by Adams integrates the digital credentials (DC) technology of Brands with the identity-based encryption (IBE) technology of Boneh and Franklin to create an IBE scheme that demonstrably enhances privacy for users. We refer to this scheme as a privacy-preserving identity-based encryption (PP-IBE) construction. In this paper, we discuss the concrete implementation considerations for PP-IBE and provide a detailed instantiation (based on q-torsion groups in supersingular elliptic curves) that may be useful both for proof-of-concept purposes and for pedagogical purposes.
文摘Identity-Based Encryption (IBE) has seen limited adoption, largely due to the absolute trust that must be placed in the private key generator (PKG)—an authority that computes the private keys for all the users in the environment. Several constructions have been proposed to reduce the trust required in the PKG (and thus preserve the privacy of users), but these have generally relied on unrealistic assumptions regarding non-collusion between various entities in the system. Unfortunately, these constructions have not significantly improved IBE adoption rates in real-world environments. In this paper, we present a construction that reduces trust in the PKG without unrealistic non-collusion assumptions. We achieve this by incorporating a novel combination of digital credential technology and bilinear maps, and making use of multiple randomly-chosen entities to complete certain tasks. The main result and primary contribution of this paper are a thorough security analysis of this proposed construction, examining the various entity types, attacker models, and collusion opportunities in this environment. We show that this construction can prevent, or at least mitigate, all considered attacks. We conclude that our construction appears to be effective in preserving user privacy and we hope that this construction and its security analysis will encourage greater use of IBE in real-world environments.
文摘为使移动设备更加方便快捷地解密存储于云端的外包数据,根据基于身份的广播加密(IBBE)系统和基于身份的加密(IBE)系统,使用Green等提出的解密外包的技术(GREEN M,HOHENBERGER S,WATERS B.Outsourcing the decryption of ABE ciphertexts.Proceedings of the 20th USENIX Conference on Security.Berkeley:USENIX Association,2011:34),提出一种改进的非对称跨加密系统的代理重加密(MACPRE)方案。该方案更适合计算能力有限的移动设备安全共享云端数据。移动用户在解密重加密后的数据时,运行一次指数运算和一次配对运算便可以将明文恢复,大大提高了移动用户解密的效率,降低了移动用户的能耗。该方案的安全性可以归约到底层的IBE方案和IBBE方案的安全性。理论分析和实验结果表明,该方案使得移动设备花费较少的时间便可以将存储在云端的数据解密,缓解了移动设备计算能力的不足,实用性较强。
