Self-Generated-Certificate Public Key Cryptography(SGC-PKC) ,is the enhanced version of Certificateless Public Key Cryptography(CL-PKC) . It preserves all advantages of CL-PKC. Similar to CL-PKC,every user is given a ...Self-Generated-Certificate Public Key Cryptography(SGC-PKC) ,is the enhanced version of Certificateless Public Key Cryptography(CL-PKC) . It preserves all advantages of CL-PKC. Similar to CL-PKC,every user is given a partial private key by the KGC and generates his own private key and corresponding public key. In addition,it can defend against the Denial-of-Decryption(DoD) Attack. In this paper,we propose a new approach to construction SGC-PKE scheme that derived from a new application of chameleon hash and give a concrete scheme. It is the first scheme which has flexible public key and reaches Girault's trusted level 3,the same level as is enjoyed in a traditional PKI.展开更多
Public Key Encryption with Keyword Search (PEKS), an indispensable part of searchable encryption, is stock-in- trade for both protecting data and providing operability of encrypted data. So far most of PEKS schemes ...Public Key Encryption with Keyword Search (PEKS), an indispensable part of searchable encryption, is stock-in- trade for both protecting data and providing operability of encrypted data. So far most of PEKS schemes have been established on Identity-Based Cryptography (IBC) with key escrow problem inherently. Such problem severely restricts the promotion of IBC-based Public Key Infrastructure including PEKS component. Hence, Certificateless Public Key Cryptography (CLPKC) is efficient to remove such problem. CLPKC is introduced into PEKS, and a general model of Certificateless PEKS (CLPEKS) is formalized. In addition, a practical CLPEKS scheme is constructed with security and efficiency analyses. The proposal is secure channel free, and semantically secure against adaptive chosen keyword attack and keyword guessing attack. To illustrate the superiority, massive experiments are conducted on Enron Email dataset which is famous in information retrieval field. Compared with existed constructions, CLPEKS improves the efficiency in theory and removes the key escrow problem.展开更多
Certificateless public key cryptography was introduced to overcome the key escrow limitation of the identity-based cryptography. It combines the advantages of the identity-based cryptography and the traditional PKI. M...Certificateless public key cryptography was introduced to overcome the key escrow limitation of the identity-based cryptography. It combines the advantages of the identity-based cryptography and the traditional PKI. Many certificateless public key encryption and signature schemes have been proposed. However, the key agreement in CL-PKE is seldom discussed. In this paper, we present a new certificateless two party authentication key agreement protocol and prove its security attributes. Compared with the existing protocol, our protocol is more efficient.展开更多
An efficient authenticated key agreement protocol is proposed, which makesuse of bilinear pairings and self-certificd public keys. Its security is based on the securityassumptions of the bilinear Diff ie-Hellman probl...An efficient authenticated key agreement protocol is proposed, which makesuse of bilinear pairings and self-certificd public keys. Its security is based on the securityassumptions of the bilinear Diff ie-Hellman problem and the computational Diffie-Hellman problem.Users can choose their private keys independently. The public keys and identities of users can beverified implicitly when the session key being generating in a logically single step. A trusted KeyGeneration Center is no longer requiredas in the ID-based authenticated key agreement protocolsCompared with existing authenticated key agreement protocols from pairings, the. new proposedprotocol is more efficient and secure.展开更多
A new public key encryption scheme is proposed in this paper, which is based on a hard problem over ergodic matrices. The security of this scheme is equal to the MQ-problem: multivariate quadratic equations over fini...A new public key encryption scheme is proposed in this paper, which is based on a hard problem over ergodic matrices. The security of this scheme is equal to the MQ-problem: multivariate quadratic equations over finite fields. This problem has been shown to be NP-complete and can't be solved with polynomial time algorithm.展开更多
A proxy signature scheme with message recovery using self-certified public key is proposed, which withstands public key substitution attacks, active attacks, and forgery attacks. The proposed scheme accomplishes the t...A proxy signature scheme with message recovery using self-certified public key is proposed, which withstands public key substitution attacks, active attacks, and forgery attacks. The proposed scheme accomplishes the tasks of public key verification, proxy signature verification, and message recovery in a logically single step. In addition, the proposed scheme satisfies all properties of strong proxy signature and does not use secure channel in the communication between the original signer and the proxy signature signer.展开更多
Cloud computing, a recently emerged paradigm faces major challenges in achieving the privacy of migrated data, network security, etc. Too many cryptographic technologies are raised to solve these issues based on ident...Cloud computing, a recently emerged paradigm faces major challenges in achieving the privacy of migrated data, network security, etc. Too many cryptographic technologies are raised to solve these issues based on identity, attributes and prediction algorithms yet;these techniques are highly prone to attackers. This would raise a need of an effective encryption technique, which would ensure secure data migration. With this scenario, our proposed methodology Efficient Probabilistic Public Key Encryption(EPPKE) is optimized with Covariance Matrix Adaptation Evolution Strategies(CMA-ES). It ensures data integrity through the Luhn algorithm with BLAKE 2b encapsulation. This enables an optimized security to the data which is migrated through cloud. The proposed methodology is implemented in Open Stack with Java Language. It achieves better results by providing security compared to other existing techniques like RSA, IBA, ABE, PBE, etc.展开更多
Internet key exchange (IKE) is an automated key exchange mechanism that is used to facilitate the transfer of IPSec security associations (SAs). Public key infrastructure (PKI) is considered as a key element for provi...Internet key exchange (IKE) is an automated key exchange mechanism that is used to facilitate the transfer of IPSec security associations (SAs). Public key infrastructure (PKI) is considered as a key element for providing security to new distributed communication networks and services. In this paper, we concentrate on the properties of the protocol of Phase 1 IKE. After investigating IKE protocol and PKI technology, we combine IKE protocol and PKI and present an implementation scheme of the IKE based on PKI. Then, we give a logic analysis of the proposed protocol with the BAN-logic and discuss the security of the protocol. The result indicates that the protocol is correct and satisfies the security requirements of Internet key exchange.展开更多
This paper presents a multivariate public key cryptographic scheme over a finite field with odd prime characteristic.The idea of embedding and layering is manifested in its construction.The security of the scheme is a...This paper presents a multivariate public key cryptographic scheme over a finite field with odd prime characteristic.The idea of embedding and layering is manifested in its construction.The security of the scheme is analyzed in detail,and this paper indicates that the scheme can withstand the up to date differential cryptanalysis.We give heuristic arguments to show that this scheme resists all known attacks.展开更多
Modular arithmetic is a fundamental operation and plays an important role in public key cryptosystem. A new method and its theory evidence on the basis of modular arithmetic with large integer modulus-changeable modul...Modular arithmetic is a fundamental operation and plays an important role in public key cryptosystem. A new method and its theory evidence on the basis of modular arithmetic with large integer modulus-changeable modulus algorithm is proposed to improve the speed of the modular arithmetic in the presented paper. For changeable modulus algorithm, when modular computation of modulo n is difficult, it can be realized by computation of modulo n-1 and n-2 on the perquisite of easy modular computations of modulo n-1 and modulo n-2. The conclusion is that the new method is better than the direct method by computing the modular arithmetic operation with large modulus. Especially, when computations of modulo n-1 and modulo n-2 are easy and computation of modulo n is difficult, this new method will be faster and has more advantages than other algorithms on modular arithmetic. Lastly, it is suggested that the proposed method be applied in public key cryptography based on modular multiplication and modular exponentiation with large integer modulus effectively展开更多
The idempotent semirings Rmax and Rmin play a crucial role in several areas of mathematics and their applications such as discrete mathematics, algebraic geometry, computer science, computer languages, linguistic prob...The idempotent semirings Rmax and Rmin play a crucial role in several areas of mathematics and their applications such as discrete mathematics, algebraic geometry, computer science, computer languages, linguistic problems, optimization theory, discrete event systems, fuzzy logics. In this paper we consider the expansion of the semirings Rmax and Rmin with residuals and describe how to use these expended semirings in public key cryptography.展开更多
In order to ensure the security of cloud storage, on the basis of the analysis of cloud storage security requirements, this paper puts forward a kind of" hidden mapping hyper-combined public key management scheme...In order to ensure the security of cloud storage, on the basis of the analysis of cloud storage security requirements, this paper puts forward a kind of" hidden mapping hyper-combined public key management scheme based on the hyperelliptic curve crypto system, which is applicable to the distributed cloud storage. A series of operation processes of the key management are elaborated, including key distribution, key updating and key agreement, etc. Analysis shows that the scheme can solve the problem of large-scale key management and storage issues in cloud storage effectively. The scheme feathers high efficiency and good scalability. It is able to resist collusion attack and ensure safe and reliable service provided by the cloud storaee system展开更多
Trapdoor is a key component of public key cryptography design which is the essential security foundation of modern cryptography.Normally,the traditional way in designing a trapdoor is to identify a computationally har...Trapdoor is a key component of public key cryptography design which is the essential security foundation of modern cryptography.Normally,the traditional way in designing a trapdoor is to identify a computationally hard problem,such as the NPC problems.So the trapdoor in a public key encryption mechanism turns out to be a type of limited resource.In this paper,we generalize the methodology of adversarial learning model in artificial intelligence and introduce a novel way to conveniently obtain sub-optimal and computationally hard trapdoors based on the automatic information theoretic search technique.The basic routine is constructing a generative architecture to search and discover a probabilistic reversible generator which can correctly encoding and decoding any input messages.The architecture includes a trapdoor generator built on a variational autoencoder(VAE)responsible for searching the appropriate trapdoors satisfying a maximum of entropy,a random message generator yielding random noise,and a dynamic classifier taking the results of the two generator.The evaluation of our construction shows the architecture satisfying basic indistinguishability of outputs under chosen-plaintext attack model(CPA)and high efficiency in generating cheap trapdoors.展开更多
In the proposed photo certificate, the principal component is the image, for example, the user's photo. User-related fields, such as the subject's name, the issuer's name, and the expiration period, which are meani...In the proposed photo certificate, the principal component is the image, for example, the user's photo. User-related fields, such as the subject's name, the issuer's name, and the expiration period, which are meaningful to users, are embedded into the surface of the photo by using a visible watermark algorithm, so that the reader can capture this information without the requirement for special software. The remaining fields in the certificate are embedded into a marked photo. Later, the whole photo certificate is eryptographically signed by certification authority (CA) private key to guarantee the integrity of our photo certificate. By such arrangement, the eertificate's verification is divided into two layers. The first layer is human visual system oriented and the second layer is the software-oriented. User can determine whether the user's photo and its subject's name are consistent and cheek whether the expired period is valid first. The second layer's verification is lunched only when the first layer's verification is passed. To sum up, the proposed photo certificate not only inherits the functions of a traditional certificate, but also provides a friendlier operational environment of X.509 certificate.展开更多
A best algorithm generated scheme is proposed in the paper by making use of the thought of evolutionary algorithm, which can generate dynamically the best algorithm of generating primes in RSA cryptography under diffe...A best algorithm generated scheme is proposed in the paper by making use of the thought of evolutionary algorithm, which can generate dynamically the best algorithm of generating primes in RSA cryptography under different conditions. Taking into account the factors of time, space and security integrated, this scheme possessed strong practicability. The paper also proposed a model of multi-degree parallel evolutionary algorithm to evaluate synthetically the efficiency and security of the public key cryptography. The model contributes to designing public key cryptography system too.展开更多
External direct product of some low layer groups such as braid groups and general Artin groups, with a kind of special group action on it, provides a secure cryptographic computation platform, which can keep secure in...External direct product of some low layer groups such as braid groups and general Artin groups, with a kind of special group action on it, provides a secure cryptographic computation platform, which can keep secure in the quantum computing epoch. Three hard problems on this new platform, Subgroup Root Problem, Multi-variant Subgroup Root Problem and Subgroup Action Problem are presented and well analyzed, which all have no relations with conjugacy. New secure public key encryption system and key agreement protocol are designed based on these hard problems. The new cryptosystems can be implemented in a general group environment other than in braid or Artin groups.展开更多
To prevent active attack, we propose a new threshold signature scheme usingself-certified public keys, which makes use of hash function and discrete logarithm problem. Thescheme has less commutnication and computation...To prevent active attack, we propose a new threshold signature scheme usingself-certified public keys, which makes use of hash function and discrete logarithm problem. Thescheme has less commutnication and computation cost than previous schemes. Furthermore, the signatmeprocess of the proposed scheme is non-interactive.展开更多
This paper compares two types of access methods in 3G telecommunication systems, registration based access method and alternative access method. Through analyzing their common ground, we establish a public-key based u...This paper compares two types of access methods in 3G telecommunication systems, registration based access method and alternative access method. Through analyzing their common ground, we establish a public-key based uniform access framework, which combines different access methods into one unified model and provides more scalability and flexibility. Then an improved wireless authentication protocol is introduced into the framework, which gives an example of how unification is obtained by using public key technology. Since original protocol has flaws, an improved one is proposed based on security investigation. Improved authentication protocol overcomes the weakness of the original one, and maintains all the security features owned by old protocol. Finally, the feasibility of this framework is analyzed with consideration of current development in mobile telecommunication fields and the future trend of 3G systems. The result shows that public key technology has a promising future in 3G and Beyond 3G systems. It points out a new way for key management in future telecommunication systems.展开更多
Public Key Infrastructure (PKI) is a comprehensive information security framework for providing secure information and communication over the internet. Its need and use has grown over the years and continually grows. ...Public Key Infrastructure (PKI) is a comprehensive information security framework for providing secure information and communication over the internet. Its need and use has grown over the years and continually grows. This research work examines the current PKI framework’s validation process as operated by vendors and subscribers to identify the drawbacks and propose enhanced approaches to its validation mechanism. Using an approach of reviewing secondary data, critical weaknesses of integrity, proof of trust and single point-of-failure were identified with the current PKI framework. This study therefore advances proposed solutions to address the identified weaknesses by specifically introducing multiple Certificate Authorities, storage, visibility and searchability of subscriber information in public repository. A comprehensive detail of its implementation is proposed to address the identified weaknesses of uncertain integrity, trust for certificate authorities and prevent a single point of failure. Furthermore, the proposed enhancements are validated with the protection motivation theory and a framework for empirically testing the enhancements is suggested. Further research would be required to factor in multi-factor authentication without compromising performance.展开更多
Image secret sharing(ISS)is gaining popularity due to the importance of digital images and its wide application to cloud-based distributed storage and multiparty secure computing.Shadow image authentication generally ...Image secret sharing(ISS)is gaining popularity due to the importance of digital images and its wide application to cloud-based distributed storage and multiparty secure computing.Shadow image authentication generally includes shadow image detection and identification,and plays an important role in ISS.However,traditional dealer-participatory methods,which suffer from significant pixel expansion or storing auxiliary information,authenticate the shadow image mainly during the decoding phase,also known as unidirectional authentication.The authentication of the shadow image in the distributing(encoding)phase is also important for the participant.In this study,we introduce a public key based bidirectional shadow image authentication method in ISS without pixel expansion for a(k,n)threshold.When the dealer distributes each shadow image to a corresponding participant,the participant can authenticate the received shadow image with his/her private key.In the decoding phase,the dealer can authenticate each received shadow image with a secret key;in addition,the dealer can losslessly decode the secret image with any k or more shadow images.The proposed method is validated using theoretical analyses,illustrations,and comparisons.展开更多
基金supported by the Natural Science Foundation of China(Grant No.10990011 & No.60763009)
文摘Self-Generated-Certificate Public Key Cryptography(SGC-PKC) ,is the enhanced version of Certificateless Public Key Cryptography(CL-PKC) . It preserves all advantages of CL-PKC. Similar to CL-PKC,every user is given a partial private key by the KGC and generates his own private key and corresponding public key. In addition,it can defend against the Denial-of-Decryption(DoD) Attack. In this paper,we propose a new approach to construction SGC-PKE scheme that derived from a new application of chameleon hash and give a concrete scheme. It is the first scheme which has flexible public key and reaches Girault's trusted level 3,the same level as is enjoyed in a traditional PKI.
基金This research was supported by the National Science Foundation of China for Funding Projects (61173089,61472298) and National Statistical Science Program of China(2013LZ46).
文摘Public Key Encryption with Keyword Search (PEKS), an indispensable part of searchable encryption, is stock-in- trade for both protecting data and providing operability of encrypted data. So far most of PEKS schemes have been established on Identity-Based Cryptography (IBC) with key escrow problem inherently. Such problem severely restricts the promotion of IBC-based Public Key Infrastructure including PEKS component. Hence, Certificateless Public Key Cryptography (CLPKC) is efficient to remove such problem. CLPKC is introduced into PEKS, and a general model of Certificateless PEKS (CLPEKS) is formalized. In addition, a practical CLPEKS scheme is constructed with security and efficiency analyses. The proposal is secure channel free, and semantically secure against adaptive chosen keyword attack and keyword guessing attack. To illustrate the superiority, massive experiments are conducted on Enron Email dataset which is famous in information retrieval field. Compared with existed constructions, CLPEKS improves the efficiency in theory and removes the key escrow problem.
基金Supported by the National Natural Science Foundation of China (19501032)
文摘Certificateless public key cryptography was introduced to overcome the key escrow limitation of the identity-based cryptography. It combines the advantages of the identity-based cryptography and the traditional PKI. Many certificateless public key encryption and signature schemes have been proposed. However, the key agreement in CL-PKE is seldom discussed. In this paper, we present a new certificateless two party authentication key agreement protocol and prove its security attributes. Compared with the existing protocol, our protocol is more efficient.
文摘An efficient authenticated key agreement protocol is proposed, which makesuse of bilinear pairings and self-certificd public keys. Its security is based on the securityassumptions of the bilinear Diff ie-Hellman problem and the computational Diffie-Hellman problem.Users can choose their private keys independently. The public keys and identities of users can beverified implicitly when the session key being generating in a logically single step. A trusted KeyGeneration Center is no longer requiredas in the ID-based authenticated key agreement protocolsCompared with existing authenticated key agreement protocols from pairings, the. new proposedprotocol is more efficient and secure.
基金Supported bythe Specialized Research Fundfor the Doctoral Programof Higher Education of China (20050183032) the Science Foundation Project of Jilin Province Education Office(2005180 ,2005181)
文摘A new public key encryption scheme is proposed in this paper, which is based on a hard problem over ergodic matrices. The security of this scheme is equal to the MQ-problem: multivariate quadratic equations over finite fields. This problem has been shown to be NP-complete and can't be solved with polynomial time algorithm.
文摘A proxy signature scheme with message recovery using self-certified public key is proposed, which withstands public key substitution attacks, active attacks, and forgery attacks. The proposed scheme accomplishes the tasks of public key verification, proxy signature verification, and message recovery in a logically single step. In addition, the proposed scheme satisfies all properties of strong proxy signature and does not use secure channel in the communication between the original signer and the proxy signature signer.
文摘Cloud computing, a recently emerged paradigm faces major challenges in achieving the privacy of migrated data, network security, etc. Too many cryptographic technologies are raised to solve these issues based on identity, attributes and prediction algorithms yet;these techniques are highly prone to attackers. This would raise a need of an effective encryption technique, which would ensure secure data migration. With this scenario, our proposed methodology Efficient Probabilistic Public Key Encryption(EPPKE) is optimized with Covariance Matrix Adaptation Evolution Strategies(CMA-ES). It ensures data integrity through the Luhn algorithm with BLAKE 2b encapsulation. This enables an optimized security to the data which is migrated through cloud. The proposed methodology is implemented in Open Stack with Java Language. It achieves better results by providing security compared to other existing techniques like RSA, IBA, ABE, PBE, etc.
文摘Internet key exchange (IKE) is an automated key exchange mechanism that is used to facilitate the transfer of IPSec security associations (SAs). Public key infrastructure (PKI) is considered as a key element for providing security to new distributed communication networks and services. In this paper, we concentrate on the properties of the protocol of Phase 1 IKE. After investigating IKE protocol and PKI technology, we combine IKE protocol and PKI and present an implementation scheme of the IKE based on PKI. Then, we give a logic analysis of the proposed protocol with the BAN-logic and discuss the security of the protocol. The result indicates that the protocol is correct and satisfies the security requirements of Internet key exchange.
基金ACKNOWLEDGEMENT This work is supported by the National Natural Science Foundation of China under Grant No.61103210, the Mathematical Tianyuan Foundation of China under Grant No.11226274, the Fundamental Research Funds for the Central Universities: DKYPO 201301, 2014 XSYJ09, YZDJ1102 and YZDJ1103, the Fund of Beijing Electronic Science and Technology Institute: 2014 TD2OHW, and the Fund of BESTI Information Security Key Laboratory: YQNJ1005.
文摘This paper presents a multivariate public key cryptographic scheme over a finite field with odd prime characteristic.The idea of embedding and layering is manifested in its construction.The security of the scheme is analyzed in detail,and this paper indicates that the scheme can withstand the up to date differential cryptanalysis.We give heuristic arguments to show that this scheme resists all known attacks.
基金Supported by the National Natural Science Foun-dation of China (60373087)
文摘Modular arithmetic is a fundamental operation and plays an important role in public key cryptosystem. A new method and its theory evidence on the basis of modular arithmetic with large integer modulus-changeable modulus algorithm is proposed to improve the speed of the modular arithmetic in the presented paper. For changeable modulus algorithm, when modular computation of modulo n is difficult, it can be realized by computation of modulo n-1 and n-2 on the perquisite of easy modular computations of modulo n-1 and modulo n-2. The conclusion is that the new method is better than the direct method by computing the modular arithmetic operation with large modulus. Especially, when computations of modulo n-1 and modulo n-2 are easy and computation of modulo n is difficult, this new method will be faster and has more advantages than other algorithms on modular arithmetic. Lastly, it is suggested that the proposed method be applied in public key cryptography based on modular multiplication and modular exponentiation with large integer modulus effectively
文摘The idempotent semirings Rmax and Rmin play a crucial role in several areas of mathematics and their applications such as discrete mathematics, algebraic geometry, computer science, computer languages, linguistic problems, optimization theory, discrete event systems, fuzzy logics. In this paper we consider the expansion of the semirings Rmax and Rmin with residuals and describe how to use these expended semirings in public key cryptography.
基金This work was supported in part by the National Science Foundation Project of P.R.China,the Fundamental Research Funds for the Central Universities under Grant No.FRF-TP-14-046A2
文摘In order to ensure the security of cloud storage, on the basis of the analysis of cloud storage security requirements, this paper puts forward a kind of" hidden mapping hyper-combined public key management scheme based on the hyperelliptic curve crypto system, which is applicable to the distributed cloud storage. A series of operation processes of the key management are elaborated, including key distribution, key updating and key agreement, etc. Analysis shows that the scheme can solve the problem of large-scale key management and storage issues in cloud storage effectively. The scheme feathers high efficiency and good scalability. It is able to resist collusion attack and ensure safe and reliable service provided by the cloud storaee system
基金the National Natural Science Foundation of China(No.61572521,U1636114)National Key Project of Research and Development Plan(2017YFB0802000)+2 种基金Natural Science Foundation of Shaanxi Province(2021JM-252)Innovative Research Team Project of Engineering University of APF(KYTD201805)Fundamental Research Project of Engineering University of PAP(WJY201910).
文摘Trapdoor is a key component of public key cryptography design which is the essential security foundation of modern cryptography.Normally,the traditional way in designing a trapdoor is to identify a computationally hard problem,such as the NPC problems.So the trapdoor in a public key encryption mechanism turns out to be a type of limited resource.In this paper,we generalize the methodology of adversarial learning model in artificial intelligence and introduce a novel way to conveniently obtain sub-optimal and computationally hard trapdoors based on the automatic information theoretic search technique.The basic routine is constructing a generative architecture to search and discover a probabilistic reversible generator which can correctly encoding and decoding any input messages.The architecture includes a trapdoor generator built on a variational autoencoder(VAE)responsible for searching the appropriate trapdoors satisfying a maximum of entropy,a random message generator yielding random noise,and a dynamic classifier taking the results of the two generator.The evaluation of our construction shows the architecture satisfying basic indistinguishability of outputs under chosen-plaintext attack model(CPA)and high efficiency in generating cheap trapdoors.
文摘In the proposed photo certificate, the principal component is the image, for example, the user's photo. User-related fields, such as the subject's name, the issuer's name, and the expiration period, which are meaningful to users, are embedded into the surface of the photo by using a visible watermark algorithm, so that the reader can capture this information without the requirement for special software. The remaining fields in the certificate are embedded into a marked photo. Later, the whole photo certificate is eryptographically signed by certification authority (CA) private key to guarantee the integrity of our photo certificate. By such arrangement, the eertificate's verification is divided into two layers. The first layer is human visual system oriented and the second layer is the software-oriented. User can determine whether the user's photo and its subject's name are consistent and cheek whether the expired period is valid first. The second layer's verification is lunched only when the first layer's verification is passed. To sum up, the proposed photo certificate not only inherits the functions of a traditional certificate, but also provides a friendlier operational environment of X.509 certificate.
基金Supported by the Hi-Tech Research and Development Program of China(2002AA1Z1490)
文摘A best algorithm generated scheme is proposed in the paper by making use of the thought of evolutionary algorithm, which can generate dynamically the best algorithm of generating primes in RSA cryptography under different conditions. Taking into account the factors of time, space and security integrated, this scheme possessed strong practicability. The paper also proposed a model of multi-degree parallel evolutionary algorithm to evaluate synthetically the efficiency and security of the public key cryptography. The model contributes to designing public key cryptography system too.
基金Supported by the National Natural Science Funda-tion of China (60403027)
文摘External direct product of some low layer groups such as braid groups and general Artin groups, with a kind of special group action on it, provides a secure cryptographic computation platform, which can keep secure in the quantum computing epoch. Three hard problems on this new platform, Subgroup Root Problem, Multi-variant Subgroup Root Problem and Subgroup Action Problem are presented and well analyzed, which all have no relations with conjugacy. New secure public key encryption system and key agreement protocol are designed based on these hard problems. The new cryptosystems can be implemented in a general group environment other than in braid or Artin groups.
文摘To prevent active attack, we propose a new threshold signature scheme usingself-certified public keys, which makes use of hash function and discrete logarithm problem. Thescheme has less commutnication and computation cost than previous schemes. Furthermore, the signatmeprocess of the proposed scheme is non-interactive.
基金Sponsored by the National Natural Science Foundation of China (Grant No. 60203012).
文摘This paper compares two types of access methods in 3G telecommunication systems, registration based access method and alternative access method. Through analyzing their common ground, we establish a public-key based uniform access framework, which combines different access methods into one unified model and provides more scalability and flexibility. Then an improved wireless authentication protocol is introduced into the framework, which gives an example of how unification is obtained by using public key technology. Since original protocol has flaws, an improved one is proposed based on security investigation. Improved authentication protocol overcomes the weakness of the original one, and maintains all the security features owned by old protocol. Finally, the feasibility of this framework is analyzed with consideration of current development in mobile telecommunication fields and the future trend of 3G systems. The result shows that public key technology has a promising future in 3G and Beyond 3G systems. It points out a new way for key management in future telecommunication systems.
文摘Public Key Infrastructure (PKI) is a comprehensive information security framework for providing secure information and communication over the internet. Its need and use has grown over the years and continually grows. This research work examines the current PKI framework’s validation process as operated by vendors and subscribers to identify the drawbacks and propose enhanced approaches to its validation mechanism. Using an approach of reviewing secondary data, critical weaknesses of integrity, proof of trust and single point-of-failure were identified with the current PKI framework. This study therefore advances proposed solutions to address the identified weaknesses by specifically introducing multiple Certificate Authorities, storage, visibility and searchability of subscriber information in public repository. A comprehensive detail of its implementation is proposed to address the identified weaknesses of uncertain integrity, trust for certificate authorities and prevent a single point of failure. Furthermore, the proposed enhancements are validated with the protection motivation theory and a framework for empirically testing the enhancements is suggested. Further research would be required to factor in multi-factor authentication without compromising performance.
基金Project supported by the National Natural Science Foundation of China(No.62271496)。
文摘Image secret sharing(ISS)is gaining popularity due to the importance of digital images and its wide application to cloud-based distributed storage and multiparty secure computing.Shadow image authentication generally includes shadow image detection and identification,and plays an important role in ISS.However,traditional dealer-participatory methods,which suffer from significant pixel expansion or storing auxiliary information,authenticate the shadow image mainly during the decoding phase,also known as unidirectional authentication.The authentication of the shadow image in the distributing(encoding)phase is also important for the participant.In this study,we introduce a public key based bidirectional shadow image authentication method in ISS without pixel expansion for a(k,n)threshold.When the dealer distributes each shadow image to a corresponding participant,the participant can authenticate the received shadow image with his/her private key.In the decoding phase,the dealer can authenticate each received shadow image with a secret key;in addition,the dealer can losslessly decode the secret image with any k or more shadow images.The proposed method is validated using theoretical analyses,illustrations,and comparisons.