A weakness of unforgeability is found in Ma and Chen scheme, and the root cause is the susceptive linear design in the scheme. In order to avoid the weakness and susceptive linear design, an improvement by means of tw...A weakness of unforgeability is found in Ma and Chen scheme, and the root cause is the susceptive linear design in the scheme. In order to avoid the weakness and susceptive linear design, an improvement by means of two mechanisms including quadratic residue and composite discrete logarithm is proposed, which can defeat the forgery attacks in Ma and Chen scheme. The new scheme remains good confidentiality, public verifiability and efficiency.展开更多
Through cryptanalysis of the improved scheme of a generalized group-oriented threshold signcryption schemes,it is found that the improved scheme can effectively resist conspiracy attack and forgery attack,but does not...Through cryptanalysis of the improved scheme of a generalized group-oriented threshold signcryption schemes,it is found that the improved scheme can effectively resist conspiracy attack and forgery attack,but does not have semantic security and public verification function,and sends threshold signcryption by the secret secure channel,which increases the communication costs and potential safety hazards of the system.A new group-oriented publicly verifiable threshold signcryption scheme is proposed on the basis of the improved scheme,the new scheme overcomes the drawbacks of the improved scheme,which not only provides with semantic security and public verification function,but also can send threshold signcryption by the public channel.展开更多
Since Libert and Quisquater's identity based signcryption scheme cannot provide public verifiability after research, the paper proposes a new identity based signcryption scheme. The scheme uses quadratic residue a...Since Libert and Quisquater's identity based signcryption scheme cannot provide public verifiability after research, the paper proposes a new identity based signcryption scheme. The scheme uses quadratic residue and pairings over elliptic curves to realize public verifiability. By analysis the scheme is proved to be more efficient than Libert and Quisquater's scheme. Moreover, a security proof of the original scheme is presented in the random oracle model.展开更多
In this paper, we point out that Libert and Quisquater’s signcryption scheme cannot provide public verifiability. Then we present a new identity based signcryption scheme using quadratic residue and pairings over ell...In this paper, we point out that Libert and Quisquater’s signcryption scheme cannot provide public verifiability. Then we present a new identity based signcryption scheme using quadratic residue and pairings over elliptic curves. It combines the functionalities of both public verifiability and forward security at the same time. Under the Bilinear Diffie-Hellman and quadratic residue assumption, we describe the new scheme that is more secure and can be some-what more efficient than Libert and Quisquater’s one.展开更多
Signcryption has been a rapidly emerging efficient approach to achieve authenticity and confidentiality within a logic single step. However, it is still a difficult problem to realize public verifiability of signcrypt...Signcryption has been a rapidly emerging efficient approach to achieve authenticity and confidentiality within a logic single step. However, it is still a difficult problem to realize public verifiability of signcryption in an efficient and secure way. Here, we present a generic solution to realize public verifiability based on quadratic residue.展开更多
In recent years, with the development of quantum cryptography, quantum signature has also made great achievement. However,the effectiveness of all the quantum signature schemes reported in the literature can only be v...In recent years, with the development of quantum cryptography, quantum signature has also made great achievement. However,the effectiveness of all the quantum signature schemes reported in the literature can only be verified by a designated person.Therefore, its wide applications are limited. For solving this problem, a new quantum proxy signature scheme using EPR quantumentanglement state and unitary transformation to generate proxy signature is presented. Proxy signer announces his public key whenhe generates the final signature. According to the property of unitary transformation and quantum one-way function, everyone canverify whether the signature is effective or not by the public key. So the quantum proxy signature scheme in our paper can be publicverified. The quantum key distribution and one-time pad encryption algorithm guarantee the unconditional security of this scheme.Analysis results show that this new scheme satisfies strong non-counterfeit and strong non-disavowal.展开更多
In a blind signcryption, besides the functions of digital signature and encryption algorithm for authentication and confidentiality, a user can delegates another user＇s capability with the anonymity of the participan...In a blind signcryption, besides the functions of digital signature and encryption algorithm for authentication and confidentiality, a user can delegates another user＇s capability with the anonymity of the participants guaranteed. Some blind signcryptions were proposed but without a blind signcryption with public public verifiability. In this paper, verifiability that is proved to be efficient and secure is proposed. Through the security analysis, we proved that the scheme can offer confidentiality, integrity, unforgeability, non-repudiation and public verifiability. The coming research direction is also summarized.展开更多
Chosen Ciphertext Attack （CCA） security on the standard model is widely accepted as the standard security notion for the public key cryptosystem. The existing CCA-secure public key cryptosystems on the standard mode...Chosen Ciphertext Attack （CCA） security on the standard model is widely accepted as the standard security notion for the public key cryptosystem. The existing CCA-secure public key cryptosystems on the standard model are expensive in terms of efficiency and practicality. In this paper, an efficient and practical public key cryptosystem is presented over the group of signed quadratic residues. It is provably secure against CCA on the standard model. Furthermore, public verifiability for this scheme is also realized in the way that projects the verification privacy key into public key on trapdoor pretending. It will be useful to devise efficient CCA-secure threshold and proxy re-encryption schemes on the standard model.展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.60273049 and 90104005).
文摘A weakness of unforgeability is found in Ma and Chen scheme, and the root cause is the susceptive linear design in the scheme. In order to avoid the weakness and susceptive linear design, an improvement by means of two mechanisms including quadratic residue and composite discrete logarithm is proposed, which can defeat the forgery attacks in Ma and Chen scheme. The new scheme remains good confidentiality, public verifiability and efficiency.
基金Supported by the National Natural Science Foundation of China(No.61179026)the Fundamental Research funds for the Centeral Universities(No.3122013K001)
文摘Through cryptanalysis of the improved scheme of a generalized group-oriented threshold signcryption schemes,it is found that the improved scheme can effectively resist conspiracy attack and forgery attack,but does not have semantic security and public verification function,and sends threshold signcryption by the secret secure channel,which increases the communication costs and potential safety hazards of the system.A new group-oriented publicly verifiable threshold signcryption scheme is proposed on the basis of the improved scheme,the new scheme overcomes the drawbacks of the improved scheme,which not only provides with semantic security and public verification function,but also can send threshold signcryption by the public channel.
文摘Since Libert and Quisquater's identity based signcryption scheme cannot provide public verifiability after research, the paper proposes a new identity based signcryption scheme. The scheme uses quadratic residue and pairings over elliptic curves to realize public verifiability. By analysis the scheme is proved to be more efficient than Libert and Quisquater's scheme. Moreover, a security proof of the original scheme is presented in the random oracle model.
文摘In this paper, we point out that Libert and Quisquater’s signcryption scheme cannot provide public verifiability. Then we present a new identity based signcryption scheme using quadratic residue and pairings over elliptic curves. It combines the functionalities of both public verifiability and forward security at the same time. Under the Bilinear Diffie-Hellman and quadratic residue assumption, we describe the new scheme that is more secure and can be some-what more efficient than Libert and Quisquater’s one.
基金Supported by the National Natural Science Foun-dation of China (60273049 ,60303026 ,90104005)
文摘Signcryption has been a rapidly emerging efficient approach to achieve authenticity and confidentiality within a logic single step. However, it is still a difficult problem to realize public verifiability of signcryption in an efficient and secure way. Here, we present a generic solution to realize public verifiability based on quadratic residue.
基金supported by the National Science and Technology Key Project (Grant No. 2010ZX03003-003-01)the National Basic Research Program of China (Grant No. 2007CB311203)
文摘In recent years, with the development of quantum cryptography, quantum signature has also made great achievement. However,the effectiveness of all the quantum signature schemes reported in the literature can only be verified by a designated person.Therefore, its wide applications are limited. For solving this problem, a new quantum proxy signature scheme using EPR quantumentanglement state and unitary transformation to generate proxy signature is presented. Proxy signer announces his public key whenhe generates the final signature. According to the property of unitary transformation and quantum one-way function, everyone canverify whether the signature is effective or not by the public key. So the quantum proxy signature scheme in our paper can be publicverified. The quantum key distribution and one-time pad encryption algorithm guarantee the unconditional security of this scheme.Analysis results show that this new scheme satisfies strong non-counterfeit and strong non-disavowal.
基金Supported by the Ministry of Railways Foundation of Science and Technology Development (2007X001-E)
文摘In a blind signcryption, besides the functions of digital signature and encryption algorithm for authentication and confidentiality, a user can delegates another user＇s capability with the anonymity of the participants guaranteed. Some blind signcryptions were proposed but without a blind signcryption with public public verifiability. In this paper, verifiability that is proved to be efficient and secure is proposed. Through the security analysis, we proved that the scheme can offer confidentiality, integrity, unforgeability, non-repudiation and public verifiability. The coming research direction is also summarized.
基金supported by the National Natural Science Foundation of China (Nos. 61272492, 61103231, 61103230, 61402530, and 61202492)the Natural Science Foundation of Shaanxi Provience (Nos. 2013JM8012 and 2014JQ8301)
文摘Chosen Ciphertext Attack （CCA） security on the standard model is widely accepted as the standard security notion for the public key cryptosystem. The existing CCA-secure public key cryptosystems on the standard model are expensive in terms of efficiency and practicality. In this paper, an efficient and practical public key cryptosystem is presented over the group of signed quadratic residues. It is provably secure against CCA on the standard model. Furthermore, public verifiability for this scheme is also realized in the way that projects the verification privacy key into public key on trapdoor pretending. It will be useful to devise efficient CCA-secure threshold and proxy re-encryption schemes on the standard model.
