Cloud computing has reached the peak of Gartner hype cycle,and now the focus of the whole telecom industry is the ability to scale data storage with minimal investment.But data privacy and communication issues will oc...Cloud computing has reached the peak of Gartner hype cycle,and now the focus of the whole telecom industry is the ability to scale data storage with minimal investment.But data privacy and communication issues will occur with the increment of the cloud data storage.The key privacy concern for scalability is caused by the dynamic membership allocation and multi-owner data sharing.This paper addresses the issues faced by multiple owners through a mutual authentication mechanism using the Enhanced Elliptic Curve Diffie-Hellman(EECDH)key exchange protocol along with the Elliptic Curve Digital Signature Algorithm(ECDSA).The proposed EECDH scheme is used to exchange the secured shared key among multiple owners and also to eliminate the Man-In-The-Middle(MITM)attacks with less computational complexity.By leveraging these algorithms,the integrity of data sharing among multiple owners is ensured.The EECDH improves the level of security only slightly increasing the time taken to encrypt and decrypt the data,and it is secured against the MITM attacks,which is experimented using the AVISPA tool.展开更多
Certificateless public key cryptography is a new paradigm introduced by Al-Riyami and Paterson.It eliminates the need of the certificates in traditional public key cryptosystems and the key escrow problem in IDentity-...Certificateless public key cryptography is a new paradigm introduced by Al-Riyami and Paterson.It eliminates the need of the certificates in traditional public key cryptosystems and the key escrow problem in IDentity-based Public Key Cryptography(ID-PKC).Due to the advantages of the certificateless public key cryptography,a new efficient certificateless pairing-based signature scheme is presented,which has some advantages over previous constructions in computational cost.Based on this new signature scheme,a certificateless blind signature scheme is proposed.The security of our schemes is proven based on the hardness of computational Diffie-Hellman problem.展开更多
The design and analysis of authenticated key exchange protocol is an important problem in information security area. At present, extended Canetti-Krawczyk (eCK) model provides the strongest definition of security for ...The design and analysis of authenticated key exchange protocol is an important problem in information security area. At present, extended Canetti-Krawczyk (eCK) model provides the strongest definition of security for two party key agreement protocol, however most of the current secure protocols can not be prove to secure without Gap assumption. To avoid this phenomenon, by using twinning key technology we propose a new two party key agreement protocol TUP which is obtained by modifying the UP protocol, then in conjunction with the trapdoor test, we prove strictly that the new protocol is secure in eCK model. Compared with previous protocols, the security assumption of new proposal is more standard and weaker, and it also solves an open problem in ProvSec'09.展开更多
In 1999, Seo and Sweeney proposed a simple authenticated key agreement protocol that was designed to act as a Diffie-Hellman key agreement protocol with user authentication.Various attacks on this protocol are describ...In 1999, Seo and Sweeney proposed a simple authenticated key agreement protocol that was designed to act as a Diffie-Hellman key agreement protocol with user authentication.Various attacks on this protocol are described and enhanced in the literature. Recently, Ku and Wang proposed an improved authenticated key agreement protocol, where they asserted the protocol could withstand the existing attacks. This paper shows that Ku and Wang's protocol is still vulnerable to the modification attack and presents an improved authenticated key agreement protocol to enhance the security of Ku and Wang's protocol. The protocol has more efficient performance by replacing exponentiation operations with message authentication code operations.展开更多
In current cloud computing system, large amounts of sensitive data are shared to other cloud users. To keep these data confidentiality, data owners should encrypt their data before outsourcing. We choose proxy reencry...In current cloud computing system, large amounts of sensitive data are shared to other cloud users. To keep these data confidentiality, data owners should encrypt their data before outsourcing. We choose proxy reencryption (PRE) as the cloud data encryption technique. In a PRE system, a semi-trusted proxy can transform a ciphertext under one public key into a ciphertext of the same message under another public key, but the proxy cannot gain any information about the message. In this paper, we propose a certificateless PRE (CL-PRE) scheme without pairings. The security of the proposed scheme can be proved to be equivalent to the computational Dire- Hellman (CDH) problem in the random oracle model. Compared with other existing CL-PRE schemes, our scheme requires less computation cost and is significantly more efficient. The new scheme does not need the public key certificates to guarantee validity of public keys and solves the key escrow problem in identity-based public key cryptography.展开更多
In this paper, based on the verifiable pair and identity-based threshold cryptography, a novel identity-based (ID-based) threshold decryption scheme (IDTDS) is proposed, which is provably secure against adaptive c...In this paper, based on the verifiable pair and identity-based threshold cryptography, a novel identity-based (ID-based) threshold decryption scheme (IDTDS) is proposed, which is provably secure against adaptive chosen cipbertext attack under the computational bilinear Diffie-Hellman (CBDH) problem assumption in the random oracle. The pubic cheekability of ciphertext in the IDTDS is given by simply creating a signed E1Gamal encryption instead of a noninteractive zero-knowledge proof. Furthermore, we introduce a modified verifiable pairing to ensure all decryption shares are consistent. Our scheme is more efficient in verification than the schemes considered previously.展开更多
Proxy signature schemes enable an entity to del- egate its signing rights to any other party, called proxy signer. As a variant of proxy signature primitive, proxy multi- signature allows a group of original signers t...Proxy signature schemes enable an entity to del- egate its signing rights to any other party, called proxy signer. As a variant of proxy signature primitive, proxy multi- signature allows a group of original signers to delegate their signing capabilities to a single proxy signer in such a way that the proxy signer can sign a message on behalf of the group of original signers. We propose a concrete ID-based proxy multi-signature scheme from bilinear pairings. The proposed scheme is existential unforgeable against adaptively chosen message and given ID-attack in random oracle model under the computational Diltie-Hellman (CDH) assumption. The fascinating property of new scheme is that the size of a proxy multi-signature is independent of the number of original sign- ers. Furthermore the proposed scheme is simple and com- putationally more efficient than other ID-based proxy multi- signature schemes.展开更多
Searchable public key encryption enables a storage server to retrieve the publicly encrypted data without revealing the original data contents.It offers a perfect cryptographic solution to encrypted data retrieval in ...Searchable public key encryption enables a storage server to retrieve the publicly encrypted data without revealing the original data contents.It offers a perfect cryptographic solution to encrypted data retrieval in encrypted data storage systems.Certificateless cryptography(CLC)is a novel cryptographic primitive that has many merits.It overcomes the key escrow problem in identity-based cryptosystems and the cumbersome certificate problem in conventional public key cryptosystems.Motivated by the appealing features of CLC,three certificateless encryption with keyword search(CLEKS)schemes were presented in the literature.However,all of them were constructed with the costly bilinear pairing and thus are not suitable for the devices that have limited computing resources and battery power.So,it is interesting and worthwhile to design a CLEKS scheme without using bilinear pairing.In this study,we put forward a pairing-free CLEKS scheme that does not exploit bilinear pairing.We strictly prove that the scheme achieves keyword ciphertext indistinguishability against adaptive chosen-keyword attacks under the complexity assumption of the computational Diffie-Hellman problem in the random oracle model.Efficiency comparison and the simulation show that it enjoys better performance than the previous pairing-based CLEKS schemes.In addition,we briefly introduce three extensions of the proposed CLEKS scheme.展开更多
文摘Cloud computing has reached the peak of Gartner hype cycle,and now the focus of the whole telecom industry is the ability to scale data storage with minimal investment.But data privacy and communication issues will occur with the increment of the cloud data storage.The key privacy concern for scalability is caused by the dynamic membership allocation and multi-owner data sharing.This paper addresses the issues faced by multiple owners through a mutual authentication mechanism using the Enhanced Elliptic Curve Diffie-Hellman(EECDH)key exchange protocol along with the Elliptic Curve Digital Signature Algorithm(ECDSA).The proposed EECDH scheme is used to exchange the secured shared key among multiple owners and also to eliminate the Man-In-The-Middle(MITM)attacks with less computational complexity.By leveraging these algorithms,the integrity of data sharing among multiple owners is ensured.The EECDH improves the level of security only slightly increasing the time taken to encrypt and decrypt the data,and it is secured against the MITM attacks,which is experimented using the AVISPA tool.
基金the National Natural Science Foundation of China (No.60673070)the Natural Science Foundation of Jiangsu Province (No.BK2006217)the Open Project of the Key Lab. on Computer Networks and Information Security (Xidian University) of Ministry of Education of China(No.20040105)
文摘Certificateless public key cryptography is a new paradigm introduced by Al-Riyami and Paterson.It eliminates the need of the certificates in traditional public key cryptosystems and the key escrow problem in IDentity-based Public Key Cryptography(ID-PKC).Due to the advantages of the certificateless public key cryptography,a new efficient certificateless pairing-based signature scheme is presented,which has some advantages over previous constructions in computational cost.Based on this new signature scheme,a certificateless blind signature scheme is proposed.The security of our schemes is proven based on the hardness of computational Diffie-Hellman problem.
文摘The design and analysis of authenticated key exchange protocol is an important problem in information security area. At present, extended Canetti-Krawczyk (eCK) model provides the strongest definition of security for two party key agreement protocol, however most of the current secure protocols can not be prove to secure without Gap assumption. To avoid this phenomenon, by using twinning key technology we propose a new two party key agreement protocol TUP which is obtained by modifying the UP protocol, then in conjunction with the trapdoor test, we prove strictly that the new protocol is secure in eCK model. Compared with previous protocols, the security assumption of new proposal is more standard and weaker, and it also solves an open problem in ProvSec'09.
基金Supported by the National Natural Science Foundation of China (No.60203004) Post-doctor Foundation of China (No.2003033155).
文摘In 1999, Seo and Sweeney proposed a simple authenticated key agreement protocol that was designed to act as a Diffie-Hellman key agreement protocol with user authentication.Various attacks on this protocol are described and enhanced in the literature. Recently, Ku and Wang proposed an improved authenticated key agreement protocol, where they asserted the protocol could withstand the existing attacks. This paper shows that Ku and Wang's protocol is still vulnerable to the modification attack and presents an improved authenticated key agreement protocol to enhance the security of Ku and Wang's protocol. The protocol has more efficient performance by replacing exponentiation operations with message authentication code operations.
基金the National Natural Science Foundation of China(No.61133014)
文摘In current cloud computing system, large amounts of sensitive data are shared to other cloud users. To keep these data confidentiality, data owners should encrypt their data before outsourcing. We choose proxy reencryption (PRE) as the cloud data encryption technique. In a PRE system, a semi-trusted proxy can transform a ciphertext under one public key into a ciphertext of the same message under another public key, but the proxy cannot gain any information about the message. In this paper, we propose a certificateless PRE (CL-PRE) scheme without pairings. The security of the proposed scheme can be proved to be equivalent to the computational Dire- Hellman (CDH) problem in the random oracle model. Compared with other existing CL-PRE schemes, our scheme requires less computation cost and is significantly more efficient. The new scheme does not need the public key certificates to guarantee validity of public keys and solves the key escrow problem in identity-based public key cryptography.
基金Supported by the National Natural Science Foundation of China (60970119, 60803149)the National Basic Research Program of China (973 Program) (2007CB311201)
文摘In this paper, based on the verifiable pair and identity-based threshold cryptography, a novel identity-based (ID-based) threshold decryption scheme (IDTDS) is proposed, which is provably secure against adaptive chosen cipbertext attack under the computational bilinear Diffie-Hellman (CBDH) problem assumption in the random oracle. The pubic cheekability of ciphertext in the IDTDS is given by simply creating a signed E1Gamal encryption instead of a noninteractive zero-knowledge proof. Furthermore, we introduce a modified verifiable pairing to ensure all decryption shares are consistent. Our scheme is more efficient in verification than the schemes considered previously.
文摘Proxy signature schemes enable an entity to del- egate its signing rights to any other party, called proxy signer. As a variant of proxy signature primitive, proxy multi- signature allows a group of original signers to delegate their signing capabilities to a single proxy signer in such a way that the proxy signer can sign a message on behalf of the group of original signers. We propose a concrete ID-based proxy multi-signature scheme from bilinear pairings. The proposed scheme is existential unforgeable against adaptively chosen message and given ID-attack in random oracle model under the computational Diltie-Hellman (CDH) assumption. The fascinating property of new scheme is that the size of a proxy multi-signature is independent of the number of original sign- ers. Furthermore the proposed scheme is simple and com- putationally more efficient than other ID-based proxy multi- signature schemes.
基金Project supported by the National Natural Science Foundation of China(Nos.61772009 and U1736112)the Fundamental Research Funds for the Central Universities,China(Nos.2016B10114 and 2017B17014)the Natural Science Foundation of Jiangsu Province,China(No.BK20181304)
文摘Searchable public key encryption enables a storage server to retrieve the publicly encrypted data without revealing the original data contents.It offers a perfect cryptographic solution to encrypted data retrieval in encrypted data storage systems.Certificateless cryptography(CLC)is a novel cryptographic primitive that has many merits.It overcomes the key escrow problem in identity-based cryptosystems and the cumbersome certificate problem in conventional public key cryptosystems.Motivated by the appealing features of CLC,three certificateless encryption with keyword search(CLEKS)schemes were presented in the literature.However,all of them were constructed with the costly bilinear pairing and thus are not suitable for the devices that have limited computing resources and battery power.So,it is interesting and worthwhile to design a CLEKS scheme without using bilinear pairing.In this study,we put forward a pairing-free CLEKS scheme that does not exploit bilinear pairing.We strictly prove that the scheme achieves keyword ciphertext indistinguishability against adaptive chosen-keyword attacks under the complexity assumption of the computational Diffie-Hellman problem in the random oracle model.Efficiency comparison and the simulation show that it enjoys better performance than the previous pairing-based CLEKS schemes.In addition,we briefly introduce three extensions of the proposed CLEKS scheme.