Attribute revocation is inevitable and al- so important for Attribute-Based Encryption （ABE） in practice. However, little attention has been paid to this issue, and it retrains one of the rmin obsta-cles for the app...Attribute revocation is inevitable and al- so important for Attribute-Based Encryption （ABE） in practice. However, little attention has been paid to this issue, and it retrains one of the rmin obsta-cles for the application of ABE. Most of existing ABE schemes support attribute revocation work under indirect revocation model such that all the users＇ private keys will be affected when the revo-cation events occur. Though some ABE schemes have realized revocation under direct revocation model such that the revocation list is embedded in the ciphertext and none of the users＇ private keys will be affected by revocation, they mostly focused on the user revocation that revokes the user＇s whole attributes, or they can only be proven to be selectively secure. In this paper, we first define a model of adaptively secure ABE supporting the at- tribute revocation under direct revocation model. Then we propose a Key-Policy ABE （KP-ABE） scheme and a Ciphertext-Policy ABE （CP-ABE） scheme on composite order bilinear groups. Finally, we prove our schemes to be adaptively secure by employing the methodology of dual system eno cryption.展开更多
Attribute-based encryption is drawing more attention with its inherent attractive properties which are potential to be widely used in the newly developing cloud computing. However, one of the main obstacles for its ap...Attribute-based encryption is drawing more attention with its inherent attractive properties which are potential to be widely used in the newly developing cloud computing. However, one of the main obstacles for its application is how to revoke the attributes of the users, though some ABE schemes have realized revocation, they mostly focused on the user revocation that revokes the user＇s whole attributes, or attribute revocation under the indirect revocation model such that all the users＇ private keys will be affected by the revocation. In this paper, we define the model of CP-ABE supporting the attribute revocation under the direct revocation model, in which the revocation list is embed in the ciphertext and none of the users＇ private keys will be affected by the revocation process. Then we propose a generic construction, and prove its security with the decision q-BDHE assumption.展开更多
Access control is a key mechanism to secure outsourced data in mobile clouds. Some existing solutions are proposed to enforce flexible access control on outsourced data or reduce the computations performed by mobile d...Access control is a key mechanism to secure outsourced data in mobile clouds. Some existing solutions are proposed to enforce flexible access control on outsourced data or reduce the computations performed by mobile devices. However, less attention has been paid to the efficiency of revocation when there are mobile devices needed to be revoked. In this paper, we put forward a new solution, referred to as flexible access control with outsourceable revocation(FACOR) for mobile clouds. The FACOR applies the attribute-based encryption to enable flexible access control on outsourced data, and allows mobile users to outsource the time-consuming encryption and decryption computations to proxies, with only requiring attributes authorization to be fully trusted. As an advantageous feature, FACOR provides an outsourceable revocation for mobile users to reduce the complicated attribute-based revocation operations. The security analysis shows that our FACOR scheme achieves data security against collusion attacks and unauthorized accesses from revoked users. Both theoretical and experimental results confirm that our proposed scheme greatly reliefs the mobile devices from heavy encryption and decryption computations, as well as the complicated revocation of access rights in mobile clouds.展开更多
Attribute-based encryption(ABE) supports the fine-grained sharing of encrypted data.In some common designs,attributes are managed by an attribute authority that is supposed to be fully trustworthy.This concept implies...Attribute-based encryption(ABE) supports the fine-grained sharing of encrypted data.In some common designs,attributes are managed by an attribute authority that is supposed to be fully trustworthy.This concept implies that the attribute authority can access all encrypted data,which is known as the key escrow problem.In addition,because all access privileges are defined over a single attribute universe and attributes are shared among multiple data users,the revocation of users is inefficient for the existing ABE scheme.In this paper,we propose a novel scheme that solves the key escrow problem and supports efficient user revocation.First,an access controller is introduced into the existing scheme,and then,secret keys are generated corporately by the attribute authority and access controller.Second,an efficient user revocation mechanism is achieved using a version key that supports forward and backward security.The analysis proves that our scheme is secure and efficient in user authorization and revocation.展开更多
With the advent of cloud storage, users can share their own data in the remote cloud as a group. To ensure the security of stored data and the normal operation of public auditing, once a user is revoked from the user ...With the advent of cloud storage, users can share their own data in the remote cloud as a group. To ensure the security of stored data and the normal operation of public auditing, once a user is revoked from the user group, the data files he signed should be resigned by other legal users in the group. In this paper, we propose a new re-signature scheme utilizing backup files to rebuild data which can resist the collusion between the cloud and revoked users, and we use Shamir Secret Sharing Scheme to encrypt data in the multi-managers system which can separate the authority of the group managers. Moreover, our scheme is more practical because we do not need managers to be online all the time. Performance evaluation shows that our mechanism can improve the efficiency of the process of data re-signature.展开更多
Among several post quantum primitives proposed in the past few decades, lattice-based cryptography is considered as the most promising one, due to its underlying rich combinatorial structure, and the worst-case to ave...Among several post quantum primitives proposed in the past few decades, lattice-based cryptography is considered as the most promising one, due to its underlying rich combinatorial structure, and the worst-case to average-case reductions. The first lattice-based group signature scheme with verifier-local revocation(VLR) is treated as the first quantum-resistant scheme supported member revocation, and was put forward by Langlois et al. This VLR group signature(VLR-GS) has group public key size of O(nm log N log q), and a signature size of O(tm log N log q log β). Nguyen et al. constructed a simple efficient group signature from lattice, with significant advantages in bit-size of both the group public key and the signature. Based on their work, we present a VLR-GS scheme with group public key size of O(nm log q) and signature size of O(tm log q). Our group signature has notable advantages: support of membership revocation, and short in both the public key size and the signature size.展开更多
Vehicular Ad-hoc NETworks(VANETs)enable cooperative behaviors in vehicular environments and are seen as an integral component of Intelligent Transportation Systems(ITSs).The security of VANETs is crucial for their suc...Vehicular Ad-hoc NETworks(VANETs)enable cooperative behaviors in vehicular environments and are seen as an integral component of Intelligent Transportation Systems(ITSs).The security of VANETs is crucial for their successful deployment and widespread adoption.A critical aspect of preserving the security and privacy of VANETs is the efficient revocation of the ability of misbehaving or malicious vehicles to participate in the network.This is usually achieved by revoking the validity of the digital certificates of the offending nodes and by maintaining and distributing an accurate Certificate Revocation List(CRL).The immediate revocation of misbehaving vehicles is of prime importance for the safety of other vehicles and users.In this paper,we present a decentralized revocation approach based on Shamir’s secret sharing to revoke misbehaving vehicles with very low delays.Besides enhancing VANETs’security,our proposed protocol limits the size of the revocation list to the number of the revoked vehicles.Consequently,the authentication process is more efficient,and the communication overhead is reduced.We experimentally evaluate our protocol to demonstrate that it provides a reliable solution to the scalability,efficiency and security of VANETs.展开更多
Up to now, how to construct an efficient secure group signature scheme, which needs not to reset the system when some group members' signing keys are exposed, is still a difficult problem. A construction concernin...Up to now, how to construct an efficient secure group signature scheme, which needs not to reset the system when some group members' signing keys are exposed, is still a difficult problem. A construction concerning revocation of group members is an ideal one if it satisfies forward security which makes it more attractive for not sacrificing the security of past signatures of deleted members. This paper analyses the problem and gives a construction in which the group manager can be un-trustworthy. The scheme is efficient even when the number of revoked members is large.展开更多
How to find efficient and secure member- ship revocation algorithms is one of the most important issues standing in the way of real-world applications of group signatures. In this paper, the proof of knowledge of divi...How to find efficient and secure member- ship revocation algorithms is one of the most important issues standing in the way of real-world applications of group signatures. In this paper, the proof of knowledge of divisibility is given and a novel membership revocation method in ACJT group signature scheme is proposed： the group manager issues the product E of the public keys of current members in the group, when a group member wants to sign, he should not only proves that he has a membership certificate, but also proves that the public key in his certificate divides exactly the public key product E with zero knowledge. The proposed method is efficient since the group manager only needs one division and one exponentiation when a group member is deleted, while the signing and verifying procedure are independent of the number of current group members and excluded members, as well as the original group public key and membership certificates needn＇t be changed.展开更多
In recent years,several random key pre-distribution schemes have been proposed to bootstrap keys for encryption,but the problem of key and node revocation has received relatively little attention.In this paper,based o...In recent years,several random key pre-distribution schemes have been proposed to bootstrap keys for encryption,but the problem of key and node revocation has received relatively little attention.In this paper,based on a random key pre-distribution scheme using clustering,we present a novel random key revoca-tion protocol,which is suitable for large scale networks greatly and removes compromised information efficiently.The revocation protocol can guarantee network security by using less memory consumption and communication load,and combined by centralized and distributed revoca-tion,having virtues of timeliness and veracity for revoca-tion at the same time.展开更多
A new group key management scheme against the unreliable wireless communication channel and unsafe environment was proposed for wireless sensor network(WSN).In the proposed scheme,broadcast polynomial, generated over ...A new group key management scheme against the unreliable wireless communication channel and unsafe environment was proposed for wireless sensor network(WSN).In the proposed scheme,broadcast polynomial, generated over finite field F_q based on the secret sharing,was employed to revoke compromised sensor nodes.In order to tolerate key-update message loss,group session keys were generated as one-way hash chain sequence and distributed in advance.The analysis showes that the scheme has better performance in terms of the computation and communication overhead.展开更多
Cloud data sharing service,which allows a group of people to access and modify the shared data,is one of the most popular and efficient working styles in enterprises.Recently,there is an uprising trend that enterprise...Cloud data sharing service,which allows a group of people to access and modify the shared data,is one of the most popular and efficient working styles in enterprises.Recently,there is an uprising trend that enterprises tend to move their IT service from local to cloud to ease the management and reduce the cost.Under the new cloud environment,the cloud users require the data integrity verification to inspect the data service at the cloud side.Several recent studies have focused on this application scenario.In these studies,each user within a group is required to sign a data block created or modified by him.While a user is revoked,all the data previously signed by him should be resigned.In the existing research,the resigning process is dependent on the revoked user.However,cloud users are autonomous.They may exit the system at any time without notifying the system admin and even are revoked due to misbehaviors.As the developers in the cloud-based software development platform,they are voluntary and not strictly controlled by the system.Due to this feature,cloud users may not always follow the cloud service protocol.They may not participate in generating the resigning key and may even expose their secret keys after being revoked.If the signature is not resigned in time,the subsequent verification will be affected.And if the secret key is exposed,the shared data will be maliciously modified by the attacker who grasps the key.Therefore,forcing a revoked user to participate in the revocation process will lead to efficiency and security problems.As a result,designing a practical and efficient integrity verification scheme that supports this scenario is highly desirable.In this paper,we identify this challenging problem as the asynchronous revocation,in which the revocation operations(i.e.,re-signing key generation and resigning process)and the user's revocation are asynchronous.All the revocation operations must be able to be performed without the participation of the revoked user.Even more ambitiously,the revocation process should not rely on any special entity,such as the data owner or a trusted agency.To address this problem,we propose a novel public data integrity verification mechanism in which the data blocks signed by the revoked user will be resigned by another valid user.From the perspectives of security and practicality,the revoked user does not participate in the resigning process and the re-signing key generation.Our scheme allows anyone in the cloud computing system to act as the verifier to publicly and efficiently verify the integrity of the shared data using Homomorphic Verifiable Tags(HVTs).Moreover,the proposed scheme resists the collusion attack between the cloud server and the malicious revoked users.The numerical analysis and experimental results further validate the high efficiency and scalability of the proposed scheme.The experimental results manifest that re-signing 10,000 data blocks only takes 3.815 s and a user can finish the verification in 300 ms with a 99% error detection probability.展开更多
This work proposes authentication based on identity as a way to increase the efficiency and security of communications in vehicular ad-hoc networks. When using identity-based cryptography to achieve certificateless au...This work proposes authentication based on identity as a way to increase the efficiency and security of communications in vehicular ad-hoc networks. When using identity-based cryptography to achieve certificateless authentication, membership revocation is not a trivial problem. Thus, in order to improve the performance of revocation in such networks, the use of a dynamic authenticated data structure based on perfect k-ary hash trees combined with a duplex version of the new standard SHA-3 is here presented. Efficient algorithms in the used revocation trees allow reaching a refresh rate of at most simple updates per inserted node. Consequently, the proposal is especially useful for situations with frequent revocations, which are foreseeable when vehicular ad- hoc networks are widely deployed.展开更多
Fog computing is a concept that extends the paradigm of cloud computing to the network edge. The goal of fog computing is to situate resources in the vicinity of end users. As with cloud computing, fog computing provi...Fog computing is a concept that extends the paradigm of cloud computing to the network edge. The goal of fog computing is to situate resources in the vicinity of end users. As with cloud computing, fog computing provides storage services. The data owners can store their confidential data in many fog nodes, which could cause more challenges for data sharing security. In this paper, we present a novel architecture for data sharing in a fog environment. We explore the benefits of fog computing in addressing one-to-many data sharing applications. This architecture sought to outperform the cloud-based architecture and to ensure further enhancements to system performance, especially from the perspective of security. We will address the security challenges of data sharing, such as fine-grained access control, data confidentiality, collusion resistance, scalability, and the issue of user revocation. Keeping these issues in mind, we will secure data sharing in fog computing by combining attributebased encryption and proxy re-encryption techniques. Findings of this study indicate that our system has the response and processing time faster than classical cloud systems. Further, experimental results show that our system has an efficient user revocation mechanism, and that it provides high scalability and sharing of data in real time with low latency.展开更多
In order to resist some prisoner who have received rewards of commutation to implement some illegal or criminal behavior in the course of imprisonment, the system of commutation revocation must be established, which c...In order to resist some prisoner who have received rewards of commutation to implement some illegal or criminal behavior in the course of imprisonment, the system of commutation revocation must be established, which can advantage imprisonment and reduce the costs of imprisonment. The system of commutation revocation can obey to the criminal policy of temper justice with mercy and the principle of ＂collecting mistakes whenever discovered＂ and obtain the penalty goal of special prevention. In order to protect some prisoner＇ s benefit, the prisoner who be revoked the rewards of commutation can take part in the course of juice, the postbox which be opened only by the NPC and committee must be installed in prison. This will be advantage of some prisoner who be revoked the rewards of commutation appealing to the NPC and committee. Because of weakness of necessarily and execution, the system of commutation revocation cannot be established when the prisoner have been released currently.展开更多
Since the enactment of the Civil Code,the creditor's right of revocation in China has undergone significant development and has become increasingly refined.However,in practical application,issues persist regarding...Since the enactment of the Civil Code,the creditor's right of revocation in China has undergone significant development and has become increasingly refined.However,in practical application,issues persist regarding the lack of consensus on the relationship between the creditor's right of revocation and the application of malicious collusion rules,the ambiguity in standards for determining the fraudulent nature of the debtor's actions,and the incomplete realization of the legal effects of the creditor's right of revocation.These issues can be addressed through a three-tiered structure of'norm selection,constituent elements,and legal effect realization'In norm selection,the focus should shift from substantive law to procedural law.Malicious collusion should be positioned as a defense that courts may invoke ex officio.It should be clearly established that the procedural application of the creditor's right of revocation follows malicious collusion in order of precedence.In terms of constituent elements,a dual standard should be adopted to assess the fraudulent nature of the debtor's actions.This standard should specifically address the determination of fraudulence at the time the debtor's actions are undertaken and at the time the creditor exercises their rights.In terms of legal effect realization,on the one hand,creditors should be granted the right to request the return of property from the counterparty and to apply for enforcement against the counterparty;on the other hand,in specific circumstances,the counterparty should be imposed with a notice obligation,requiring them to notify the creditor when returning property to the debtor.展开更多
With the popularity of the Internet of Vehicles(IoV),a large amount of data is being generated every day.How to securely share data between the IoV operator and various value-added service providers becomes one of the...With the popularity of the Internet of Vehicles(IoV),a large amount of data is being generated every day.How to securely share data between the IoV operator and various value-added service providers becomes one of the critical issues.Due to its flexible and efficient fine-grained access control feature,Ciphertext-Policy Attribute-Based Encryption(CP-ABE)is suitable for data sharing in IoV.However,there are many flaws in most existing CP-ABE schemes,such as attribute privacy leakage and key misuse.This paper proposes a Traceable and Revocable CP-ABE-based Data Sharing with Partially hidden policy for IoV(TRE-DSP).A partially hidden access structure is adopted to hide sensitive user attribute values,and attribute categories are sent along with the ciphertext to effectively avoid privacy exposure.In addition,key tracking and malicious user revocation are introduced with broadcast encryption to prevent key misuse.Since the main computation task is outsourced to the cloud,the burden of the user side is relatively low.Analysis of security and performance demonstrates that TRE-DSP is more secure and practical for data sharing in IoV.展开更多
Conditional proxy re-encryption(CPRE)is an effective cryptographic primitive language that enhances the access control mechanism and makes the delegation of decryption permissions more granular,but most of the attribu...Conditional proxy re-encryption(CPRE)is an effective cryptographic primitive language that enhances the access control mechanism and makes the delegation of decryption permissions more granular,but most of the attribute-based conditional proxy re-encryption(AB-CPRE)schemes proposed so far do not take into account the importance of user attributes.A weighted attribute-based conditional proxy re-encryption(WAB-CPRE)scheme is thus designed to provide more precise decryption rights delegation.By introducing the concept of weight attributes,the quantity of system attributes managed by the server is reduced greatly.At the same time,a weighted tree structure is constructed to simplify the expression of access structure effectively.With conditional proxy re-encryption,large amounts of data and complex computations are outsourced to cloud servers,so the data owner(DO)can revoke the user’s decryption rights directly with minimal costs.The scheme proposed achieves security against chosen plaintext attacks(CPA).Experimental simulation results demonstrated that the decryption time is within 6–9 ms,and it has a significant reduction in communication and computation cost on the user side with better functionality compared to other related schemes,which enables users to access cloud data on devices with limited resources.展开更多
It is secure for customers to store and share their sensitive data in the cryptographic cloud storage.However,the revocation operation is a sure performance killer in the cryptographic access control system.To optimiz...It is secure for customers to store and share their sensitive data in the cryptographic cloud storage.However,the revocation operation is a sure performance killer in the cryptographic access control system.To optimize the revocation procedure,we present a new efficient revocation scheme which is efficient,secure,and unassisted.In this scheme,the original data are first divided into a number of slices,and then published to the cloud storage.When a revocation occurs,the data owner needs only to retrieve one slice,and re-encrypt and re-publish it.Thus,the revocation process is accelerated by affecting only one slice instead of the whole data.We have applied the efficient revocation scheme to the ciphertext-policy attribute-based encryption(CP-ABE) based cryptographic cloud storage.The security analysis shows that our scheme is computationally secure.The theoretically evaluated and experimentally measured performance results show that the efficient revocation scheme can reduce the data owner's workload if the revocation occurs frequently.展开更多
文摘Attribute revocation is inevitable and al- so important for Attribute-Based Encryption （ABE） in practice. However, little attention has been paid to this issue, and it retrains one of the rmin obsta-cles for the application of ABE. Most of existing ABE schemes support attribute revocation work under indirect revocation model such that all the users＇ private keys will be affected when the revo-cation events occur. Though some ABE schemes have realized revocation under direct revocation model such that the revocation list is embedded in the ciphertext and none of the users＇ private keys will be affected by revocation, they mostly focused on the user revocation that revokes the user＇s whole attributes, or they can only be proven to be selectively secure. In this paper, we first define a model of adaptively secure ABE supporting the at- tribute revocation under direct revocation model. Then we propose a Key-Policy ABE （KP-ABE） scheme and a Ciphertext-Policy ABE （CP-ABE） scheme on composite order bilinear groups. Finally, we prove our schemes to be adaptively secure by employing the methodology of dual system eno cryption.
文摘Attribute-based encryption is drawing more attention with its inherent attractive properties which are potential to be widely used in the newly developing cloud computing. However, one of the main obstacles for its application is how to revoke the attributes of the users, though some ABE schemes have realized revocation, they mostly focused on the user revocation that revokes the user＇s whole attributes, or attribute revocation under the indirect revocation model such that all the users＇ private keys will be affected by the revocation. In this paper, we define the model of CP-ABE supporting the attribute revocation under the direct revocation model, in which the revocation list is embed in the ciphertext and none of the users＇ private keys will be affected by the revocation process. Then we propose a generic construction, and prove its security with the decision q-BDHE assumption.
基金supported in part by National High-Tech Research and Development Program of China(“863” Program)under Grant No.2015AA016004National Natural Science Foundation of China under Grants No.61173154,61272451,61572380
文摘Access control is a key mechanism to secure outsourced data in mobile clouds. Some existing solutions are proposed to enforce flexible access control on outsourced data or reduce the computations performed by mobile devices. However, less attention has been paid to the efficiency of revocation when there are mobile devices needed to be revoked. In this paper, we put forward a new solution, referred to as flexible access control with outsourceable revocation(FACOR) for mobile clouds. The FACOR applies the attribute-based encryption to enable flexible access control on outsourced data, and allows mobile users to outsource the time-consuming encryption and decryption computations to proxies, with only requiring attributes authorization to be fully trusted. As an advantageous feature, FACOR provides an outsourceable revocation for mobile users to reduce the complicated attribute-based revocation operations. The security analysis shows that our FACOR scheme achieves data security against collusion attacks and unauthorized accesses from revoked users. Both theoretical and experimental results confirm that our proposed scheme greatly reliefs the mobile devices from heavy encryption and decryption computations, as well as the complicated revocation of access rights in mobile clouds.
基金supported by the NSFC(61173141,U1536206,61232016, U1405254,61373133,61502242,61572258)BK20150925+3 种基金Fund of Jiangsu Engineering Center of Network Monitoring(KJR1402)Fund of MOE Internet Innovation Platform(KJRP1403)CICAEETthe PAPD fund
文摘Attribute-based encryption(ABE) supports the fine-grained sharing of encrypted data.In some common designs,attributes are managed by an attribute authority that is supposed to be fully trustworthy.This concept implies that the attribute authority can access all encrypted data,which is known as the key escrow problem.In addition,because all access privileges are defined over a single attribute universe and attributes are shared among multiple data users,the revocation of users is inefficient for the existing ABE scheme.In this paper,we propose a novel scheme that solves the key escrow problem and supports efficient user revocation.First,an access controller is introduced into the existing scheme,and then,secret keys are generated corporately by the attribute authority and access controller.Second,an efficient user revocation mechanism is achieved using a version key that supports forward and backward security.The analysis proves that our scheme is secure and efficient in user authorization and revocation.
基金Supported by the National Natural Science Foundation of China(61572390)the National Key Research and Development Program of China(2017YFB0802000)+1 种基金the National Natural Science Foundation of Ningbo City(201601HJ-B01382)the Open Foundation of Key Laboratory of Cognitive Radio and Information Processing of Ministry of Education(Guilin University of Electronic Technology)(CRKL160202)
文摘With the advent of cloud storage, users can share their own data in the remote cloud as a group. To ensure the security of stored data and the normal operation of public auditing, once a user is revoked from the user group, the data files he signed should be resigned by other legal users in the group. In this paper, we propose a new re-signature scheme utilizing backup files to rebuild data which can resist the collusion between the cloud and revoked users, and we use Shamir Secret Sharing Scheme to encrypt data in the multi-managers system which can separate the authority of the group managers. Moreover, our scheme is more practical because we do not need managers to be online all the time. Performance evaluation shows that our mechanism can improve the efficiency of the process of data re-signature.
基金the National Natural Science Foundations of China(Nos.61472309,61672412,61572390and 61402353)the 111 Project(No.B08038)Research Program of Anhui Education Committee(Nos.KJ2016A626,KJ2016A627)
文摘Among several post quantum primitives proposed in the past few decades, lattice-based cryptography is considered as the most promising one, due to its underlying rich combinatorial structure, and the worst-case to average-case reductions. The first lattice-based group signature scheme with verifier-local revocation(VLR) is treated as the first quantum-resistant scheme supported member revocation, and was put forward by Langlois et al. This VLR group signature(VLR-GS) has group public key size of O(nm log N log q), and a signature size of O(tm log N log q log β). Nguyen et al. constructed a simple efficient group signature from lattice, with significant advantages in bit-size of both the group public key and the signature. Based on their work, we present a VLR-GS scheme with group public key size of O(nm log q) and signature size of O(tm log q). Our group signature has notable advantages: support of membership revocation, and short in both the public key size and the signature size.
文摘Vehicular Ad-hoc NETworks(VANETs)enable cooperative behaviors in vehicular environments and are seen as an integral component of Intelligent Transportation Systems(ITSs).The security of VANETs is crucial for their successful deployment and widespread adoption.A critical aspect of preserving the security and privacy of VANETs is the efficient revocation of the ability of misbehaving or malicious vehicles to participate in the network.This is usually achieved by revoking the validity of the digital certificates of the offending nodes and by maintaining and distributing an accurate Certificate Revocation List(CRL).The immediate revocation of misbehaving vehicles is of prime importance for the safety of other vehicles and users.In this paper,we present a decentralized revocation approach based on Shamir’s secret sharing to revoke misbehaving vehicles with very low delays.Besides enhancing VANETs’security,our proposed protocol limits the size of the revocation list to the number of the revoked vehicles.Consequently,the authentication process is more efficient,and the communication overhead is reduced.We experimentally evaluate our protocol to demonstrate that it provides a reliable solution to the scalability,efficiency and security of VANETs.
基金the National Natural Science Foundation of China (No.60673081)the National Grand Foundation Research 863 Program of China (No.2006 AA01Z417).
文摘Up to now, how to construct an efficient secure group signature scheme, which needs not to reset the system when some group members' signing keys are exposed, is still a difficult problem. A construction concerning revocation of group members is an ideal one if it satisfies forward security which makes it more attractive for not sacrificing the security of past signatures of deleted members. This paper analyses the problem and gives a construction in which the group manager can be un-trustworthy. The scheme is efficient even when the number of revoked members is large.
基金supported in part by the National Nature Science Foundation of China under Grant No. 60473027
文摘How to find efficient and secure member- ship revocation algorithms is one of the most important issues standing in the way of real-world applications of group signatures. In this paper, the proof of knowledge of divisibility is given and a novel membership revocation method in ACJT group signature scheme is proposed： the group manager issues the product E of the public keys of current members in the group, when a group member wants to sign, he should not only proves that he has a membership certificate, but also proves that the public key in his certificate divides exactly the public key product E with zero knowledge. The proposed method is efficient since the group manager only needs one division and one exponentiation when a group member is deleted, while the signing and verifying procedure are independent of the number of current group members and excluded members, as well as the original group public key and membership certificates needn＇t be changed.
基金supported by the Ministry of Education Doctor Foundation in China under Grant No. 20050699037
文摘In recent years,several random key pre-distribution schemes have been proposed to bootstrap keys for encryption,but the problem of key and node revocation has received relatively little attention.In this paper,based on a random key pre-distribution scheme using clustering,we present a novel random key revoca-tion protocol,which is suitable for large scale networks greatly and removes compromised information efficiently.The revocation protocol can guarantee network security by using less memory consumption and communication load,and combined by centralized and distributed revoca-tion,having virtues of timeliness and veracity for revoca-tion at the same time.
基金the National High Technology Researchand Development Program(863)of China(Nos.2006AA01Z436,2007AA01Z452,2007AA01Z473)
文摘A new group key management scheme against the unreliable wireless communication channel and unsafe environment was proposed for wireless sensor network(WSN).In the proposed scheme,broadcast polynomial, generated over finite field F_q based on the secret sharing,was employed to revoke compromised sensor nodes.In order to tolerate key-update message loss,group session keys were generated as one-way hash chain sequence and distributed in advance.The analysis showes that the scheme has better performance in terms of the computation and communication overhead.
基金partially supported by National Key Research and Development Project No.2020YFC1522602National Natural Science Foundation of China Nos.62072349,U1811263,61572378+5 种基金Technological Innovation Major Program of Hubei Province No.2019AAA072Tarim University President Fund Doctoral Foundation Research Project No.19/1117596Xinjiang Regional Innovation Guidance Project No.2017DB004Basic and Advanced Research Projects of CSTC No.cstc2019jcyj-zdxm0102Chongqing Science and Technology Innovation Leading Talent Support Program No.CSTCCXLJRC201908Science and Technology Research Program of Chongqing Municipal Education Commission No.KJZD-K201900605.
文摘Cloud data sharing service,which allows a group of people to access and modify the shared data,is one of the most popular and efficient working styles in enterprises.Recently,there is an uprising trend that enterprises tend to move their IT service from local to cloud to ease the management and reduce the cost.Under the new cloud environment,the cloud users require the data integrity verification to inspect the data service at the cloud side.Several recent studies have focused on this application scenario.In these studies,each user within a group is required to sign a data block created or modified by him.While a user is revoked,all the data previously signed by him should be resigned.In the existing research,the resigning process is dependent on the revoked user.However,cloud users are autonomous.They may exit the system at any time without notifying the system admin and even are revoked due to misbehaviors.As the developers in the cloud-based software development platform,they are voluntary and not strictly controlled by the system.Due to this feature,cloud users may not always follow the cloud service protocol.They may not participate in generating the resigning key and may even expose their secret keys after being revoked.If the signature is not resigned in time,the subsequent verification will be affected.And if the secret key is exposed,the shared data will be maliciously modified by the attacker who grasps the key.Therefore,forcing a revoked user to participate in the revocation process will lead to efficiency and security problems.As a result,designing a practical and efficient integrity verification scheme that supports this scenario is highly desirable.In this paper,we identify this challenging problem as the asynchronous revocation,in which the revocation operations(i.e.,re-signing key generation and resigning process)and the user's revocation are asynchronous.All the revocation operations must be able to be performed without the participation of the revoked user.Even more ambitiously,the revocation process should not rely on any special entity,such as the data owner or a trusted agency.To address this problem,we propose a novel public data integrity verification mechanism in which the data blocks signed by the revoked user will be resigned by another valid user.From the perspectives of security and practicality,the revoked user does not participate in the resigning process and the re-signing key generation.Our scheme allows anyone in the cloud computing system to act as the verifier to publicly and efficiently verify the integrity of the shared data using Homomorphic Verifiable Tags(HVTs).Moreover,the proposed scheme resists the collusion attack between the cloud server and the malicious revoked users.The numerical analysis and experimental results further validate the high efficiency and scalability of the proposed scheme.The experimental results manifest that re-signing 10,000 data blocks only takes 3.815 s and a user can finish the verification in 300 ms with a 99% error detection probability.
文摘This work proposes authentication based on identity as a way to increase the efficiency and security of communications in vehicular ad-hoc networks. When using identity-based cryptography to achieve certificateless authentication, membership revocation is not a trivial problem. Thus, in order to improve the performance of revocation in such networks, the use of a dynamic authenticated data structure based on perfect k-ary hash trees combined with a duplex version of the new standard SHA-3 is here presented. Efficient algorithms in the used revocation trees allow reaching a refresh rate of at most simple updates per inserted node. Consequently, the proposal is especially useful for situations with frequent revocations, which are foreseeable when vehicular ad- hoc networks are widely deployed.
文摘Fog computing is a concept that extends the paradigm of cloud computing to the network edge. The goal of fog computing is to situate resources in the vicinity of end users. As with cloud computing, fog computing provides storage services. The data owners can store their confidential data in many fog nodes, which could cause more challenges for data sharing security. In this paper, we present a novel architecture for data sharing in a fog environment. We explore the benefits of fog computing in addressing one-to-many data sharing applications. This architecture sought to outperform the cloud-based architecture and to ensure further enhancements to system performance, especially from the perspective of security. We will address the security challenges of data sharing, such as fine-grained access control, data confidentiality, collusion resistance, scalability, and the issue of user revocation. Keeping these issues in mind, we will secure data sharing in fog computing by combining attributebased encryption and proxy re-encryption techniques. Findings of this study indicate that our system has the response and processing time faster than classical cloud systems. Further, experimental results show that our system has an efficient user revocation mechanism, and that it provides high scalability and sharing of data in real time with low latency.
文摘In order to resist some prisoner who have received rewards of commutation to implement some illegal or criminal behavior in the course of imprisonment, the system of commutation revocation must be established, which can advantage imprisonment and reduce the costs of imprisonment. The system of commutation revocation can obey to the criminal policy of temper justice with mercy and the principle of ＂collecting mistakes whenever discovered＂ and obtain the penalty goal of special prevention. In order to protect some prisoner＇ s benefit, the prisoner who be revoked the rewards of commutation can take part in the course of juice, the postbox which be opened only by the NPC and committee must be installed in prison. This will be advantage of some prisoner who be revoked the rewards of commutation appealing to the NPC and committee. Because of weakness of necessarily and execution, the system of commutation revocation cannot be established when the prisoner have been released currently.
基金supported by Zhejiang Province Philosophy and Social Science Planning Project(Grant Number:21NDQN259YB).
文摘Since the enactment of the Civil Code,the creditor's right of revocation in China has undergone significant development and has become increasingly refined.However,in practical application,issues persist regarding the lack of consensus on the relationship between the creditor's right of revocation and the application of malicious collusion rules,the ambiguity in standards for determining the fraudulent nature of the debtor's actions,and the incomplete realization of the legal effects of the creditor's right of revocation.These issues can be addressed through a three-tiered structure of'norm selection,constituent elements,and legal effect realization'In norm selection,the focus should shift from substantive law to procedural law.Malicious collusion should be positioned as a defense that courts may invoke ex officio.It should be clearly established that the procedural application of the creditor's right of revocation follows malicious collusion in order of precedence.In terms of constituent elements,a dual standard should be adopted to assess the fraudulent nature of the debtor's actions.This standard should specifically address the determination of fraudulence at the time the debtor's actions are undertaken and at the time the creditor exercises their rights.In terms of legal effect realization,on the one hand,creditors should be granted the right to request the return of property from the counterparty and to apply for enforcement against the counterparty;on the other hand,in specific circumstances,the counterparty should be imposed with a notice obligation,requiring them to notify the creditor when returning property to the debtor.
基金supported by the National Natural Science Foundation of China(No.62272076)。
文摘With the popularity of the Internet of Vehicles(IoV),a large amount of data is being generated every day.How to securely share data between the IoV operator and various value-added service providers becomes one of the critical issues.Due to its flexible and efficient fine-grained access control feature,Ciphertext-Policy Attribute-Based Encryption(CP-ABE)is suitable for data sharing in IoV.However,there are many flaws in most existing CP-ABE schemes,such as attribute privacy leakage and key misuse.This paper proposes a Traceable and Revocable CP-ABE-based Data Sharing with Partially hidden policy for IoV(TRE-DSP).A partially hidden access structure is adopted to hide sensitive user attribute values,and attribute categories are sent along with the ciphertext to effectively avoid privacy exposure.In addition,key tracking and malicious user revocation are introduced with broadcast encryption to prevent key misuse.Since the main computation task is outsourced to the cloud,the burden of the user side is relatively low.Analysis of security and performance demonstrates that TRE-DSP is more secure and practical for data sharing in IoV.
基金Programs for Science and Technology Development of Henan Province,grant number 242102210152The Fundamental Research Funds for the Universities of Henan Province,grant number NSFRF240620+1 种基金Key Scientific Research Project of Henan Higher Education Institutions,grant number 24A520015Henan Key Laboratory of Network Cryptography Technology,grant number LNCT2022-A11.
文摘Conditional proxy re-encryption(CPRE)is an effective cryptographic primitive language that enhances the access control mechanism and makes the delegation of decryption permissions more granular,but most of the attribute-based conditional proxy re-encryption(AB-CPRE)schemes proposed so far do not take into account the importance of user attributes.A weighted attribute-based conditional proxy re-encryption(WAB-CPRE)scheme is thus designed to provide more precise decryption rights delegation.By introducing the concept of weight attributes,the quantity of system attributes managed by the server is reduced greatly.At the same time,a weighted tree structure is constructed to simplify the expression of access structure effectively.With conditional proxy re-encryption,large amounts of data and complex computations are outsourced to cloud servers,so the data owner(DO)can revoke the user’s decryption rights directly with minimal costs.The scheme proposed achieves security against chosen plaintext attacks(CPA).Experimental simulation results demonstrated that the decryption time is within 6–9 ms,and it has a significant reduction in communication and computation cost on the user side with better functionality compared to other related schemes,which enables users to access cloud data on devices with limited resources.
基金Project (Nos. 61070037,61070201,and 61103016) supported by the National Natural Science Foundation of China
文摘It is secure for customers to store and share their sensitive data in the cryptographic cloud storage.However,the revocation operation is a sure performance killer in the cryptographic access control system.To optimize the revocation procedure,we present a new efficient revocation scheme which is efficient,secure,and unassisted.In this scheme,the original data are first divided into a number of slices,and then published to the cloud storage.When a revocation occurs,the data owner needs only to retrieve one slice,and re-encrypt and re-publish it.Thus,the revocation process is accelerated by affecting only one slice instead of the whole data.We have applied the efficient revocation scheme to the ciphertext-policy attribute-based encryption(CP-ABE) based cryptographic cloud storage.The security analysis shows that our scheme is computationally secure.The theoretically evaluated and experimentally measured performance results show that the efficient revocation scheme can reduce the data owner's workload if the revocation occurs frequently.
