Group Signature Scheme Research Articles

A Secure and Efficient Off-line Electronic Payment System forWireless Networks

An electronic cash system allows the exchange of digital coins with value assured by the bank’s signature and with concealed user identity. In an electronic cash system, a user can withdraw coins from the bank and then spends each coin anonymously and unlinkably. In this paper we propose a secure and efficient off-line electronic payment system based on bilinear pairings and group signature schemes. The anonymity of the customer is revocable by a trustee in case of a dispute. Because the amount of communication in the payment protocol is about 480 bits, the proposed off-line electronic payment system can be used in wireless networks with limited bandwidth.

On the Security of Two Group Signature Schemes with Forward Security

On the Security of Two Group Signature Schemes with Forward Security

An Efficient Anonymous Authentication Protocol for Secure Vehicular Communications

As vehicular communications bring the promise of improved road safety and optimized road traffic through cooperative systems applications, it becomes a prerequisite to make vehicular communications secure for the successful deployment of vehicular ad hoc networks. In this paper, we propose an efficient authentication protocol with anonymous public key certificates for secure vehicular communications. The proposed protocol follows a system model to issue on-the-fly anonymous public key certificates to vehicles by road-side units. In order to design an efficient authentication protocol, we consider a key-insulated signature scheme for certifying anonymous public keys of vehicles to the system model. We demonstrate experimental results to confirm that the proposed protocol has better performance than other protocols based on group signature schemes.

A group signature scheme based on quantum teleportation

In this paper, we present a group signature scheme using quantum teleportation. Different from classical group signature and current quantum signature schemes, which could only deliver either group signature or unconditional security, our scheme guarantees both by adopting quantum key preparation, quantum encryption algorithm and quantum teleportation. Security analysis proved that our scheme has the characteristics of group signature, non-counterfeit, non-disavowal, blindness and traceability. Our quantum group signature scheme has a foreseeable application in the e-payment system, e-government, e-business, etc.

Backward Unlinkability and Verifier-Local Revocation Group Signature Scheme with Lower Cost

In the current group signature schemes with backward unlinkability and verifier-local revocation (BU-VLR), the size of the public key is linear with the total number of time intervals, and the size of the revocation list (RL) is linear with the total number of time intervals and revoked members. Therefore, the cost is high not only in memory space but also in revocation token computation and revocation check. This paper proposes a BU-VLR group signature scheme under the DTDH assumption and the q-SDH assumption, which has short public key and RL to reduce the overheads in previous schemes. Moreover, it also has shorter signature length and smaller computation in signing.

Anonymous IEEE802.1X Authentication System Using Group Signatures

Recently, ubiquitous Internet-access services have been provided by Internet service providers (ISPs) by deploying wireless local area networks (LANs) in public spaces including stations, hotels, and coffee shops. The IEEE802.1X protocol is usually used for user authentications to allow only authorized users to access services. Then, although user personal information of access locations, services, and operations can be easily collected by ISPs and thus, their strict management has been demanded, it becomes very difficult when multiple ISPs provide roaming services by their corporations. In this paper, we present an anonymous IEEE802.1X authentication system using a group signature scheme to allow user authentication without revealing their identities. Without user identities, ISPs cannot collect personal information. As an efficient revocable group signature scheme, we adopt the verifier-local revocation (VLR) type with some modifications for use of the fast pairing computation. We show the implementation of our proposal and evaluation results where the practicality of our system is confirmed for up to 1, 000 revoked users.

Revocable Group Signature Schemes with Constant Costs for Signing and Verifying

Lots of revocable group signature schemes have been proposed so far. In one type of revocable schemes, signing and/or verifying algorithms have O(N) or O(R) complexity, where N is the group size and R is the number of revoked members. On the other hand, in Camenisch-Lysyanskaya scheme and the followers, signing and verifying algorithms have O(1) complexity. However, before signing, the updates of the secret key are required. The complexity is O(R) in the worst case. In this paper, we propose a revocable scheme with signing and verifying of O(1) complexity, where any update of secret key is not required. The compensation is the long public key of O(N). In addition, we extend it to the scheme with O( VN)-size public key, where signing and verifying have constant extra costs.

Forward-Secure Group Signatures from Pairings

To reduce the damage of key exposures, forward-secure group signature schemes have been first proposed by Song. In the forward-secure schemes, a secret key of a group member is updated by a one-way function every interval and the previous secret key is erased. Thus, even if a secret key is exposed, the signatures produced by the secret keys of previous intervals remain secure. Since the previous forward-secure group signature schemes are based on the strong RSA assumption, the signatures are longer than pairing-based group signatures. In addition, the complexity of the key update or signing/verification is O(T), where T is the total number of intervals. In this paper, a forward-secure group signature scheme from pairings is proposed. The complexity of our key update and signing/verification is O(log T).

A robust and efficient anonymous authentication protocol in VANETs

Recently, Lu et al. proposed an efficient conditional privacy preservation protocol, named ECPP, based on group signature scheme for generating anonymous certificates from roadside units (RSUs). However, ECPP does not provide unlinkability and traceability when multiple RSUs are compromised. In this paper, we make up for the limitations and propose a robust and efficient anonymous authentication protocol without loss of efficiency as compared with ECPP. Furthermore, in the proposed protocol, RSUs can issue multiple anonymous certificates to an OBU to alleviate system overheads for mutual authentication between OBUs and RSUs. In order to achieve these goals, we consider a universal re-encryption scheme and identity-based key establishment scheme as our building blocks. Several simulations are conducted to verify the efficiency and effectiveness of the proposed protocol by comparing with those of the existing ECPP.

Two Group Signature Schemes with Multiple Strategies Based on Bilinear Pairings

A group signature scheme and a threshold group signature scheme based on Bilinear Paring are proposed, there are multiple security strategies in these two schemes. These schemes have forward security which minimizes the damage caused by the exposure of any group member's signing key, and does not affect the past signatures generated by this member; meanwhile, ahead signature generated by a group member before the joining date can be prevented via this strategy. Moreover, this scheme support the group member revocable function efficiently and further has no requirement for time period limits.

Short group signature with high efficiency under standard model

This paper constructed a two-level signature scheme based on BB signature based on SDH assumption. By making certain reasonable assumptions and applying the technique of non-interactive proof system, a full anonymous dynamic short group signature scheme with the standard model was presented. The scheme was proved to satisfy the secure request of BSZ model. Compared with the latest other schemes, the scheme is more efficient and of shorter length of group signature. It allows new member to join in the group dynamically, and the group manager cannot forge any member’s signature.

Security, privacy, and accountability in wireless access networks

The presence of ubiquitous connectivity provided by wireless communications and mobile computing has changed the way humans interact with information. At the same time, it has made communication security and privacy a hot-button issue. In this article we address the security and privacy concerns in wireless access networks. We first discuss the general cryptographic means to design privacy-preserving security protocols, where the dilemma of attaining both security and privacy goals, especially user accountability vs. user privacy, is highlighted. We then present a novel authentication framework that integrates a new key management scheme based on the principle of separation of powers and an adapted construction of Boneh and Shacham's group signature scheme, as an enhanced resort to simultaneously achieve security, privacy, and accountability in wireless access networks.

Leak-free mediated group signatures1

Group signatures are a useful cryptographic construct for privacy-preserving non-repudiable authentication, and there have been many group signature schemes. In this paper, we introduce a variant of group signatures that offers two new security properties called leak-freedom and immediate-revocation. Intuitively, the former ensures that an insider (i.e., an authorized but malicious signer) be unable to convince an outsider (e.g., a signature receiver) that she indeed signed a certain message; whereas the latter ensures that the authorization for a user to issue group signatures can be immediately revoked whenever the need arises (temporarily or permanently). These properties are not offered in existing group signature schemes, nor captured by their security definitions. However, these properties might be crucial to a large class of enterprise-centric applications because they are desirable from the perspective of the enterprises who adopt group signatures or are the group signatures liability-holders (i.e., will be held accountable for the consequences of group signatures). In addition to introducing these new security properties, we present a scheme that possesses both traditional and these newly introduced properties. Our scheme is constructed using an architectural approach where a mediation server is exploited to trade on-line communications for the extra security properties, which explains why the resulting scheme is called “leak-free mediated group signatures”.

Step-out group signatures

Group signature schemes enable to create digital signatures such that the signers are hidden in a group of potential signers. However, in a case of need it is possible to reveal the actual signer either by a group administrator or collectively by the group members. We design a new kind of signatures that we call step-out group signature where the situation is reversed: any member of the group except the signer may prove that he or she was not the signer. This is a dual solution that is useful in certain scenarios: in many cases it is unnecessary to find the signer, it suffices to eliminate some potential signers (e.g. during prosecutions and court procedures). Our solution is more convenient for implementing personal data protection rules: since the signer is not revealed, there is no need to protect this information. On the other hand, the traditional scheme may lead to serious legal problems: if the legal case is to find out whether Bob has created group signature s, it might be illegal to reveal that Alice has created s.

Democratic group signatures with threshold traceability

This paper presents a concrete democratic group signature scheme which holds (t, n)-threshold traceability. In the scheme, the capability of tracing the actual signer is distributed among n group members. It gives a valid democratic group signature such that any subset with more than t members can jointly reconstruct a secret and reveal the identity of the signer. Any active adversary cannot do this even if he can corrupt up to t − 1 group members.

A Dynamic Attribute-Based Group Signature Scheme and Its Application in an Anonymous Survey for the Collection of Attribute Statistics

Recently, cryptographic schemes based on the user's attributes have been proposed. An Attribute-Based Group Signature (ABGS) scheme is a kind of group signature scheme, where a user with a set of attributes can prove anonymously whether she has these attributes or not. An access tree is applied to express the relationships among some attributes. However, previous schemes did not provide a way to change an access tree. In this paper, we propose a dynamic ABGS scheme that can change an access tree. Our ABGS is efficient in that re-issuing of the attribute certificate previously issued for each user is not necessary. The number of calculations in a pairing does not depend on the number of attributes in both signing and verifying. Finally, we discuss how our ABGS can be applied to an anonymous survey for collection of attribute statistics.

Unconditionally Secure Group Signatures

A group signature scheme introduced by Chaum and Van Heyst allows a group member to sign messages anonymously on behalf of the group. However, in the case of a dispute, the identity of a signer of a group signature can be revealed only by a privileged entity, called a group manager. The group signature scheme has mainly been studied from the viewpoint of computational security setting so far. The main contribution of this paper is to study group signature schemes in unconditional security. More specifically, we newly introduce strong security notions of unconditionally secure group signatures (USGS for short) based on the idea of those of computationally secure group signatures proposed by Bellare, Micciancio and Warinschi. We also provide a generic method to construct USGS that is provably secure in our security definition. More precisely, we construct USGS by combining an encryption scheme with a signature, and show that the constructed scheme is unconditionally secure if the encryption and the signature used in the construction are unconditionally secure. Finally, we provide an instantiation of the one-time secure group signature scheme based on the generic construction.

Remarks on "Analysis of one popular group signature scheme" in Asiacrypt 2006

At Asiacrypt 2006, Cao presented a putative framing 'attack' against the ACJT group signature scheme by Ateniese et al. This paper shows that the attack framework considered by Cao is invalid. As we clearly illustrate, there is no security weakness in the ACJT group signature scheme as long as all the detailed specifications of the original paper are being followed.

A Dynamic Attribute-Based Group Signature Scheme and Its Application in an Anonymous Survey for the Collection of Attribute Statistics

A Dynamic Attribute-Based Group Signature Scheme and Its Application in an Anonymous Survey for the Collection of Attribute Statistics

Democratic group signatures with linkability from gap Diffie-Hellman group

Democratic group signatures (DGSs) attract many researchers due to their appealing properties, i.e., anonymity, traceability and no group manager. Security results of existing work are based on decisional Diffie-Hellman (DDH) assumption. In this paper, we present a democratic group signature scheme based on any gap Diffie-Hellman (GDH) group where DDH problem is easily but computational Diffe-Hellman (CDH) problem is hard to be solved. Besides the properties of ordinary DGSs, our scheme also provides the property of linkability, i.e., any public verifier can tell whether two group signatures are generated using the same private key. Security properties of our scheme employ a new and independently interesting decisional product Diffie-Hellman (DPDH) assumption which is weaker than DDH one.