Since the end of the 1990s,cryptosystems implemented on smart cards have had to deal with two main categories of attacks:side-channel attacks and fault injection attacks.Countermeasures have been developed and validat...Since the end of the 1990s,cryptosystems implemented on smart cards have had to deal with two main categories of attacks:side-channel attacks and fault injection attacks.Countermeasures have been developed and validated against these two types of attacks,taking into account a well-defined attacker model.This work focuses on small vulnerabilities and countermeasures related to the Elliptic Curve Digital Signature Algorithm(ECDSA)algorithm.The work done in this paper focuses on protecting the ECDSA algorithm against fault-injection attacks.More precisely,we are interested in the countermeasures of scalar multiplication in the body of the elliptic curves to protect against attacks concerning only a few bits of secret may be sufficient to recover the private key.ECDSA can be implemented in different ways,in software or via dedicated hardware or a mix of both.Many different architectures are therefore possible to implement an ECDSA-based system.For this reason,this work focuses mainly on the hardware implementation of the digital signature ECDSA.In addition,the proposed ECDSA architecture with and without fault detection for the scalar multiplication have been implemented on Xilinxfield programmable gate arrays(FPGA)platform(Virtex-5).Our implementation results have been compared and discussed.Our area,frequency,area overhead and frequency degradation have been compared and it is shown that the proposed architecture of ECDSA with fault detection for the scalar multiplication allows a trade-off between the hardware overhead and the security of the ECDSA.展开更多
With the continuous expansion of the Industrial Internet of Things(IIoT),more andmore organisations are placing large amounts of data in the cloud to reduce overheads.However,the channel between cloud servers and smar...With the continuous expansion of the Industrial Internet of Things(IIoT),more andmore organisations are placing large amounts of data in the cloud to reduce overheads.However,the channel between cloud servers and smart equipment is not trustworthy,so the issue of data authenticity needs to be addressed.The SM2 digital signature algorithm can provide an authentication mechanism for data to solve such problems.Unfortunately,it still suffers from the problem of key exposure.In order to address this concern,this study first introduces a key-insulated scheme,SM2-KI-SIGN,based on the SM2 algorithm.This scheme boasts strong key insulation and secure keyupdates.Our scheme uses the elliptic curve algorithm,which is not only more efficient but also more suitable for IIoT-cloud environments.Finally,the security proof of SM2-KI-SIGN is given under the Elliptic Curve Discrete Logarithm(ECDL)assumption in the random oracle.展开更多
In this paper, a scheme which can be used in multi-user quantum digital signature is proposed. The scheme of signature and verification is based on the characters of GHZ (Greenberger-Horne-Zeilinger) states and cont...In this paper, a scheme which can be used in multi-user quantum digital signature is proposed. The scheme of signature and verification is based on the characters of GHZ (Greenberger-Horne-Zeilinger) states and controlled quantum teleportation. Different from the digital signatures based on computational complexity, this scheme is unconditional secure, and compared to the former presented quantum signature scheme, it does not rely on an arbitrator to verify the signature and realize a message can be signed by multi-user together.展开更多
Digital signature has recently played an increasingly important role in cyberspace security.Most of them are based on the public key cryptography.Public key cryptography is a mainstream cryptographic algorithm system ...Digital signature has recently played an increasingly important role in cyberspace security.Most of them are based on the public key cryptography.Public key cryptography is a mainstream cryptographic algorithm system that has been widely used in cyberspace security in recent years.The most classic public key cryptography algorithm is RSA and its difficulty is based on the large integer decomposition problem.In 2017,ISRSAC was proposed by M.Thangaval.ISRSAC has made security improvements to the RSA algorithm by increasing the complexity in factoring the value of modulus‘n’.A digital signature algorithm based on ISRSAC algorithm was completed in this paper,and furthermore,a proxy signature algorithm based on ISRSAC and two kinds of multi-signature algorithms were presented,which include sequential multi-signature and broadcasting multi-signature.展开更多
Two signature systems based on smart cards and fingerprint features are proposed. In one signature system, the cryptographic key is stored in the smart card and is only accessible when the signer's extracted fingerpr...Two signature systems based on smart cards and fingerprint features are proposed. In one signature system, the cryptographic key is stored in the smart card and is only accessible when the signer's extracted fingerprint features match his stored template. To resist being tampered on public channel, the user's message and the signed message are encrypted by the signer's public key and the user's public key, respectively. In the other signature system, the keys are generated by combining the signer's fingerprint features, check bits, and a rememberable key, and there are no matching process and keys stored on the smart card. Additionally, there is generally more than one public key in this system, that is, there exist some pseudo public keys except a real one.展开更多
Lack of efficiency in the initial key generation process is a serious shortcoming of Merkle tree signature scheme with a large number of possible signatures. Based on two kinds of Merkle trees, a new tree type signatu...Lack of efficiency in the initial key generation process is a serious shortcoming of Merkle tree signature scheme with a large number of possible signatures. Based on two kinds of Merkle trees, a new tree type signature scheme is constructed, and it is provably existentially unforgeable under adaptive chosen message attack. By decentralizing the initial key generation process of the original scheme within the signature process, a large Merkle tree with 6.87×10^10 possible signatures can be initialized in 590 milliseconds. Storing some small Merkle trees in hard disk and memory can speed up Merkle tree signature scheme. Mekle tree signature schemes are fit for trusted computing platform in most scenarios.展开更多
Due to the rapid growth of online transactions on the Internet, authentication, non-repudiation and integrity are very essential security requirements for a secure transaction. To achieve these security goals, digital...Due to the rapid growth of online transactions on the Internet, authentication, non-repudiation and integrity are very essential security requirements for a secure transaction. To achieve these security goals, digital signature is the most efficient cryptographic primitive. Many authors have proposed this scheme and prove their security and evaluate the efficiency. In our paper, we present comprehensive study of conventional digital signature schemes based on RSA, DSA and ECDSA (Elliptic Curve Digital Signature Algorithm) and the improved version of these scheme.展开更多
Visual cryptography is a cryptographic technique which emerges in the information security domain in recent years. Each of the sharing sub-keys may be a stochastic noise image or a significative image with no informat...Visual cryptography is a cryptographic technique which emerges in the information security domain in recent years. Each of the sharing sub-keys may be a stochastic noise image or a significative image with no information on the original key. But a mass of sub-keys have to be saved actually, which faces the problem of inconvenient discrimination and management. This paper presents a visual cryptography scheme based on the digital signature for image discrimination and management, applying the digital signature and the time-stamp technology to the visual cryptography scheme. The scheme both solves the problem on the storage and management of the sharing sub-keys, increases the verification of image contents, thus enhances the validity of storage and management without security effect.展开更多
The paper proposes a new sequential digital multi-signature scheme based on Knapsack public-key cryptosystem,which is different from the existing scheme.The advantages of this scheme over the existing schemes are that...The paper proposes a new sequential digital multi-signature scheme based on Knapsack public-key cryptosystem,which is different from the existing scheme.The advantages of this scheme over the existing schemes are that it simplifies the signature generation process and speeds up the signature verification process.What’s more,the scheme reduces the cost of communication and redundancy operation, and improves efficiency,and can avoid cheating by signer efficiently,so the scheme has very broad application prospects.展开更多
Objective Focusing on the s ecurity problem of authentication and confidentiality in the context of computer networks, a digital signature scheme was proposed based on the public key crypt osystem. Methods Firstly...Objective Focusing on the s ecurity problem of authentication and confidentiality in the context of computer networks, a digital signature scheme was proposed based on the public key crypt osystem. Methods Firstly, the course of digital signature based on the public key cryptosystem was given. Then, RSA and ELGamal schemes were de scribed respectively. They were the basis of the proposed scheme. Generalized EL Gamal type signature schemes were listed. After comparing with each other, one s cheme, whose Signature equation was (m+r)x=j+s modΦ(p) , was adopted in the des igning. Results Based on two well-known cryptographic assumpti ons, the factorization and the discrete logarithms, a digital signature scheme w as presented. It must be required that s' was not equal to p'q' in the signing p rocedure, because attackers could forge the signatures with high probabilities i f the discrete logarithms modulo a large prime were solvable. The variable publi c key “e” is used instead of the invariable parameter “3” in Harn's signatu re scheme to enhance the security. One generalized ELGamal type scheme made the proposed scheme escape one multiplicative inverse operation in the signing proce dure and one modular exponentiation in the verification procedure. Concl usion The presented scheme obtains the security that Harn's scheme was originally claimed. It is secure if the factorization and the discrete logarithm s are simultaneously unsolvable.展开更多
Based on the analysis of elliptic curve digital signature algorithm(ECDSA),aiming at multilevel proxy signature in which the original signer delegates the digital signature authority to several proxies and its secur...Based on the analysis of elliptic curve digital signature algorithm(ECDSA),aiming at multilevel proxy signature in which the original signer delegates the digital signature authority to several proxies and its security demands, a new multilevel proxy signature scheme based on elliptic curve discrete logarithm problem (ECDLP) is presented and its security are proved.展开更多
Fair exchange of digital signatures is an important tool for signing digital contracts, e-payment and other electronic commerce actions. An ID-based scheme of fair exchange of digital signature is proposed in this pap...Fair exchange of digital signatures is an important tool for signing digital contracts, e-payment and other electronic commerce actions. An ID-based scheme of fair exchange of digital signature is proposed in this paper. The protocol relies on a trusted third party, but is "optimistic", in that the third party is only needed in cases where one player attempts to cheat or simply crashes. The proposed scheme has properties of short signature, low computation and verification cost. It can realize exchange of digital signatures fairly and effic, iently. A key feature of our scheme is that it is identity-based, which needs no certificates and has a simple key management. To our best knowledge, this is the first identity based scheme of fair exchange of digital signatures.展开更多
In this paper, two improved digital signature schemes are presented based on the design of directed signature scheme. The peculiarity of the system is that only if the scheme is specific recipient, the signature is au...In this paper, two improved digital signature schemes are presented based on the design of directed signature scheme. The peculiarity of the system is that only if the scheme is specific recipient, the signature is authenticated. Since the scheme adds the screen of some information parameters, the difficulty of deciphered keys and the security of digital signature system are increased.展开更多
This paper describes and compares a variety of algorithms for secure transmission of information via open communication channels based on the discrete logarithm problem that do not require search for a generator (prim...This paper describes and compares a variety of algorithms for secure transmission of information via open communication channels based on the discrete logarithm problem that do not require search for a generator (primitive element). Modifications that simplify the cryptosystem are proposed, and, as a result, accelerate its performance. It is shown that hiding information via exponentiation is more efficient than other seemingly simpler protocols. Some of these protocols also provide digital signature/sender identification. Numeric illustrations are provided.展开更多
This article presents a new signcryption scheme which is based on the Schnorr digital signature algorithm. The new scheme represents my personal contribution to signcryption area. I have implemented the algorithm in a...This article presents a new signcryption scheme which is based on the Schnorr digital signature algorithm. The new scheme represents my personal contribution to signcryption area. I have implemented the algorithm in a program and here are provided the steps of the algorithm, the results and some examples. The paper also contains the presentation of the original Signcryption scheme, based on ElGamal digital signature and discusses the practical applications of Signcryption in real life. The purpose of the study is to combine the public key encryption with Schnorr digital signature in order to obtain less computational and communicational costs. Signcryption primitive is a better approach then Encrypt-then-Sign or Sign-then-Encrypt methods regarding the costs. All these algorithms offer the possibility to transmit a message over an insecure channel providing both authenticity and confidentiality.展开更多
Fail-stop signature schemes provide security for a signer against forgeries of an enemy with unlimited computational power by enabling the signer to provide a proof of forgery when a forgery happens. Chang et al propo...Fail-stop signature schemes provide security for a signer against forgeries of an enemy with unlimited computational power by enabling the signer to provide a proof of forgery when a forgery happens. Chang et al proposed a robust fail-stop blind signature scheme based on bilinear pairings. However, in this paper, it will be found that there are several mistakes in Chang et al's fail-stop blind signature scheme. Moreover, it will be pointed out that this scheme doesn't meet the property of a fail-stop signature: unconditionally secure for a signer. In Chang et al's scheme, a forger can forge a valid signature that can't be proved by a signer using the "proof of forgery". The scheme also doesn't possess the unlinkability property of a blind signature.展开更多
The concept of proxy signature introduced by Mambo, Usuda, and Okamoto allows a designated person, called a proxy signer, to sign on behalf of an original signer in 1996. However, most existing proxy signature schemes...The concept of proxy signature introduced by Mambo, Usuda, and Okamoto allows a designated person, called a proxy signer, to sign on behalf of an original signer in 1996. However, most existing proxy signature schemes does not support nonrepudiation. In this paper, we propose two secure nonrepudiable proxy signature schemes, which overcome disadvantages of M U O and K P W proxy signature schemes, respectively. The schemes proposed can withstand public key substitution attack and forge attack. In addition, our new schemes have some other advantages such as proxy signature key generation and updating using insecure channels. Our approach can also be applied to other ElGamal like proxy signature schemes.展开更多
An identity-based proxy blind signature scheme from bilinear pairings isintroduced, which combines the advantages of proxy signature and blind signature. Furthermore, ourscheme can prevent the original signer from gen...An identity-based proxy blind signature scheme from bilinear pairings isintroduced, which combines the advantages of proxy signature and blind signature. Furthermore, ourscheme can prevent the original signer from generating the proxy blind signature, thus the profitsof the proxy signer are guaranteed. We introduce bilinear pairings to minimize computationaloverhead and to improve the related performance of our scheme. In addition, the proxy blindsignature presented is non-repudiable and it fulfills perfectly the security requirements of a proxyblind signature.展开更多
基金The funding was provided by the Deanship of Scientific Research at King Khalid University through Research Group Project[grant number RGP.1/157/42].
文摘Since the end of the 1990s,cryptosystems implemented on smart cards have had to deal with two main categories of attacks:side-channel attacks and fault injection attacks.Countermeasures have been developed and validated against these two types of attacks,taking into account a well-defined attacker model.This work focuses on small vulnerabilities and countermeasures related to the Elliptic Curve Digital Signature Algorithm(ECDSA)algorithm.The work done in this paper focuses on protecting the ECDSA algorithm against fault-injection attacks.More precisely,we are interested in the countermeasures of scalar multiplication in the body of the elliptic curves to protect against attacks concerning only a few bits of secret may be sufficient to recover the private key.ECDSA can be implemented in different ways,in software or via dedicated hardware or a mix of both.Many different architectures are therefore possible to implement an ECDSA-based system.For this reason,this work focuses mainly on the hardware implementation of the digital signature ECDSA.In addition,the proposed ECDSA architecture with and without fault detection for the scalar multiplication have been implemented on Xilinxfield programmable gate arrays(FPGA)platform(Virtex-5).Our implementation results have been compared and discussed.Our area,frequency,area overhead and frequency degradation have been compared and it is shown that the proposed architecture of ECDSA with fault detection for the scalar multiplication allows a trade-off between the hardware overhead and the security of the ECDSA.
基金This work was supported in part by the National Natural Science Foundation of China(Nos.62072074,62076054,62027827,62002047)the Sichuan Science and Technology Innovation Platform and Talent Plan(Nos.2020JDJQ0020,2022JDJQ0039)+2 种基金the Sichuan Science and Technology Support Plan(Nos.2020YFSY0010,2022YFQ0045,2022YFS0220,2023YFG0148,2021YFG0131)the YIBIN Science and Technology Support Plan(No.2021CG003)the Medico-Engineering Cooperation Funds from University of Electronic Science and Technology of China(Nos.ZYGX2021YGLH212,ZYGX2022YGRH012).
文摘With the continuous expansion of the Industrial Internet of Things(IIoT),more andmore organisations are placing large amounts of data in the cloud to reduce overheads.However,the channel between cloud servers and smart equipment is not trustworthy,so the issue of data authenticity needs to be addressed.The SM2 digital signature algorithm can provide an authentication mechanism for data to solve such problems.Unfortunately,it still suffers from the problem of key exposure.In order to address this concern,this study first introduces a key-insulated scheme,SM2-KI-SIGN,based on the SM2 algorithm.This scheme boasts strong key insulation and secure keyupdates.Our scheme uses the elliptic curve algorithm,which is not only more efficient but also more suitable for IIoT-cloud environments.Finally,the security proof of SM2-KI-SIGN is given under the Elliptic Curve Discrete Logarithm(ECDL)assumption in the random oracle.
基金Supported by the National Natural Science Foundation of China (60572035, 10505005) the Foundation of Beijing Municipality Key Laboratory of Communication and Information System (JD100040513)
文摘In this paper, a scheme which can be used in multi-user quantum digital signature is proposed. The scheme of signature and verification is based on the characters of GHZ (Greenberger-Horne-Zeilinger) states and controlled quantum teleportation. Different from the digital signatures based on computational complexity, this scheme is unconditional secure, and compared to the former presented quantum signature scheme, it does not rely on an arbitrator to verify the signature and realize a message can be signed by multi-user together.
基金This work has been performed in National Natural Science Foundation of China(No.61772047,61372069)the Fundamental Research Funds for the Central Universities(No.328201902)+2 种基金National Defense Pre-research Foundation,SRF for ROCS,SEM(JY0600090102)111 project(No.B08038)China Civil Aviation Information Technology Research Base Funded Project(CAAC-ITRB-201705).
文摘Digital signature has recently played an increasingly important role in cyberspace security.Most of them are based on the public key cryptography.Public key cryptography is a mainstream cryptographic algorithm system that has been widely used in cyberspace security in recent years.The most classic public key cryptography algorithm is RSA and its difficulty is based on the large integer decomposition problem.In 2017,ISRSAC was proposed by M.Thangaval.ISRSAC has made security improvements to the RSA algorithm by increasing the complexity in factoring the value of modulus‘n’.A digital signature algorithm based on ISRSAC algorithm was completed in this paper,and furthermore,a proxy signature algorithm based on ISRSAC and two kinds of multi-signature algorithms were presented,which include sequential multi-signature and broadcasting multi-signature.
基金This project was supported by the National Science Foundation of China (60763009)China Postdoctoral Science Foundation (2005038041)Hainan Natural Science Foundation (80528).
文摘Two signature systems based on smart cards and fingerprint features are proposed. In one signature system, the cryptographic key is stored in the smart card and is only accessible when the signer's extracted fingerprint features match his stored template. To resist being tampered on public channel, the user's message and the signed message are encrypted by the signer's public key and the user's public key, respectively. In the other signature system, the keys are generated by combining the signer's fingerprint features, check bits, and a rememberable key, and there are no matching process and keys stored on the smart card. Additionally, there is generally more than one public key in this system, that is, there exist some pseudo public keys except a real one.
基金Supported by the National Natural Science Foun-dation of China (60403027)
文摘Lack of efficiency in the initial key generation process is a serious shortcoming of Merkle tree signature scheme with a large number of possible signatures. Based on two kinds of Merkle trees, a new tree type signature scheme is constructed, and it is provably existentially unforgeable under adaptive chosen message attack. By decentralizing the initial key generation process of the original scheme within the signature process, a large Merkle tree with 6.87×10^10 possible signatures can be initialized in 590 milliseconds. Storing some small Merkle trees in hard disk and memory can speed up Merkle tree signature scheme. Mekle tree signature schemes are fit for trusted computing platform in most scenarios.
文摘Due to the rapid growth of online transactions on the Internet, authentication, non-repudiation and integrity are very essential security requirements for a secure transaction. To achieve these security goals, digital signature is the most efficient cryptographic primitive. Many authors have proposed this scheme and prove their security and evaluate the efficiency. In our paper, we present comprehensive study of conventional digital signature schemes based on RSA, DSA and ECDSA (Elliptic Curve Digital Signature Algorithm) and the improved version of these scheme.
文摘Visual cryptography is a cryptographic technique which emerges in the information security domain in recent years. Each of the sharing sub-keys may be a stochastic noise image or a significative image with no information on the original key. But a mass of sub-keys have to be saved actually, which faces the problem of inconvenient discrimination and management. This paper presents a visual cryptography scheme based on the digital signature for image discrimination and management, applying the digital signature and the time-stamp technology to the visual cryptography scheme. The scheme both solves the problem on the storage and management of the sharing sub-keys, increases the verification of image contents, thus enhances the validity of storage and management without security effect.
基金supported by the National Key Lab.of Integrated Service Networks of Xidian University(No.ISN7-01)National Natural Science Foundation of China(No.60642008)
文摘The paper proposes a new sequential digital multi-signature scheme based on Knapsack public-key cryptosystem,which is different from the existing scheme.The advantages of this scheme over the existing schemes are that it simplifies the signature generation process and speeds up the signature verification process.What’s more,the scheme reduces the cost of communication and redundancy operation, and improves efficiency,and can avoid cheating by signer efficiently,so the scheme has very broad application prospects.
文摘Objective Focusing on the s ecurity problem of authentication and confidentiality in the context of computer networks, a digital signature scheme was proposed based on the public key crypt osystem. Methods Firstly, the course of digital signature based on the public key cryptosystem was given. Then, RSA and ELGamal schemes were de scribed respectively. They were the basis of the proposed scheme. Generalized EL Gamal type signature schemes were listed. After comparing with each other, one s cheme, whose Signature equation was (m+r)x=j+s modΦ(p) , was adopted in the des igning. Results Based on two well-known cryptographic assumpti ons, the factorization and the discrete logarithms, a digital signature scheme w as presented. It must be required that s' was not equal to p'q' in the signing p rocedure, because attackers could forge the signatures with high probabilities i f the discrete logarithms modulo a large prime were solvable. The variable publi c key “e” is used instead of the invariable parameter “3” in Harn's signatu re scheme to enhance the security. One generalized ELGamal type scheme made the proposed scheme escape one multiplicative inverse operation in the signing proce dure and one modular exponentiation in the verification procedure. Concl usion The presented scheme obtains the security that Harn's scheme was originally claimed. It is secure if the factorization and the discrete logarithm s are simultaneously unsolvable.
基金Supported by the National Natural Science Foun-dation of China (70471031)
文摘Based on the analysis of elliptic curve digital signature algorithm(ECDSA),aiming at multilevel proxy signature in which the original signer delegates the digital signature authority to several proxies and its security demands, a new multilevel proxy signature scheme based on elliptic curve discrete logarithm problem (ECDLP) is presented and its security are proved.
基金Supported by the National Natural Science Foun-dation of China (60372046 ,60573043)
文摘Fair exchange of digital signatures is an important tool for signing digital contracts, e-payment and other electronic commerce actions. An ID-based scheme of fair exchange of digital signature is proposed in this paper. The protocol relies on a trusted third party, but is "optimistic", in that the third party is only needed in cases where one player attempts to cheat or simply crashes. The proposed scheme has properties of short signature, low computation and verification cost. It can realize exchange of digital signatures fairly and effic, iently. A key feature of our scheme is that it is identity-based, which needs no certificates and has a simple key management. To our best knowledge, this is the first identity based scheme of fair exchange of digital signatures.
基金the Natural Science Foundation of Fujian Province (No. A0010011).
文摘In this paper, two improved digital signature schemes are presented based on the design of directed signature scheme. The peculiarity of the system is that only if the scheme is specific recipient, the signature is authenticated. Since the scheme adds the screen of some information parameters, the difficulty of deciphered keys and the security of digital signature system are increased.
文摘This paper describes and compares a variety of algorithms for secure transmission of information via open communication channels based on the discrete logarithm problem that do not require search for a generator (primitive element). Modifications that simplify the cryptosystem are proposed, and, as a result, accelerate its performance. It is shown that hiding information via exponentiation is more efficient than other seemingly simpler protocols. Some of these protocols also provide digital signature/sender identification. Numeric illustrations are provided.
文摘This article presents a new signcryption scheme which is based on the Schnorr digital signature algorithm. The new scheme represents my personal contribution to signcryption area. I have implemented the algorithm in a program and here are provided the steps of the algorithm, the results and some examples. The paper also contains the presentation of the original Signcryption scheme, based on ElGamal digital signature and discusses the practical applications of Signcryption in real life. The purpose of the study is to combine the public key encryption with Schnorr digital signature in order to obtain less computational and communicational costs. Signcryption primitive is a better approach then Encrypt-then-Sign or Sign-then-Encrypt methods regarding the costs. All these algorithms offer the possibility to transmit a message over an insecure channel providing both authenticity and confidentiality.
文摘Fail-stop signature schemes provide security for a signer against forgeries of an enemy with unlimited computational power by enabling the signer to provide a proof of forgery when a forgery happens. Chang et al proposed a robust fail-stop blind signature scheme based on bilinear pairings. However, in this paper, it will be found that there are several mistakes in Chang et al's fail-stop blind signature scheme. Moreover, it will be pointed out that this scheme doesn't meet the property of a fail-stop signature: unconditionally secure for a signer. In Chang et al's scheme, a forger can forge a valid signature that can't be proved by a signer using the "proof of forgery". The scheme also doesn't possess the unlinkability property of a blind signature.
文摘The concept of proxy signature introduced by Mambo, Usuda, and Okamoto allows a designated person, called a proxy signer, to sign on behalf of an original signer in 1996. However, most existing proxy signature schemes does not support nonrepudiation. In this paper, we propose two secure nonrepudiable proxy signature schemes, which overcome disadvantages of M U O and K P W proxy signature schemes, respectively. The schemes proposed can withstand public key substitution attack and forge attack. In addition, our new schemes have some other advantages such as proxy signature key generation and updating using insecure channels. Our approach can also be applied to other ElGamal like proxy signature schemes.
文摘An identity-based proxy blind signature scheme from bilinear pairings isintroduced, which combines the advantages of proxy signature and blind signature. Furthermore, ourscheme can prevent the original signer from generating the proxy blind signature, thus the profitsof the proxy signer are guaranteed. We introduce bilinear pairings to minimize computationaloverhead and to improve the related performance of our scheme. In addition, the proxy blindsignature presented is non-repudiable and it fulfills perfectly the security requirements of a proxyblind signature.