Qiong Huang, Guomin Yang, Duncan S. Wong, Willy Susilo
Abstract. Optimistic fair exchange is a kind of protocols to solve the problem of fair exchange between two parties. Almost all the previous work on this topic are provably secure only in the random...
On the Generic and Efficient Constructions of Secure Designated Confirmer Signatures (2008)
Guilin Wang, Joonsang Baek, Duncan S. Wong, Feng Bao
Abstract. For controlling the public verifiability of ordinary digital signatures, designated confirmer signature (DCS) schemes were introduced by Chaum at Eurocrypt 1994. In such schemes, a...
Generic Certificateless Key Encapsulation Mechanism ⋆ (2008)
Abstract. We propose the first generic construction of certificateless key encapsulation mechanism (CL-KEM) in the standard model, which is also secure against malicious-but-passive KGC attacks. It...
Recoverable and Untraceable E-Cash (2008)
Joseph K. Liu, Patrick P. Tsang, Duncan S. Wong
Abstract. In an electronic cash (e-cash) system, Recoverability means once you have lost your e-cash, you still can get back the amount of e-cash that you have lost. Untraceability means no one can...
Efficient Verifiable Ring Encryption for Ad Hoc Groups (2008)
Joseph K. Liu, Patrick P. Tsang, Duncan S. Wong
Abstract. We propose an efficient Verifiable Ring Encryption (VRE) for ad hoc groups. VRE is a kind of verifiable encryption [16,1,4,2,8] in which it can be publicly verified that there exists at...
Time Capsule Signature: Efficient and Provably Secure Constructions ⋆ (2008)
Bessie C. Hu, Duncan S. Wong, Qiong Huang, Guomin Yang
Abstract. Time Capsule Signature, first formalized by Dodis and Yum in Financial Cryptography 2005, is a digital signature scheme which allows a signature to bear a (future) time t so that the...
An Efficient One-move Nominative Signature Scheme (2008)
Abstract. A signer in a Nominative Signature (NS) scheme can arbitrarily choose a nominee, then jointly generate a signature in such a way that the signature can only be verified with the nominee’s...
Nominative signature: Application, security model and construction. Cryptology ePrint Archive (2008)
Duncan S. Wong, Xinyi Huang, Guilin Wang, Yi Mu, Willy Susilo
Abstract. Since the introduction of nominative signature in 1996, there have been only a few schemes proposed and all of them have already been found flawed. In addition, there is no formal security...
Generic Certificateless Encryption in the Standard Model (2008)
Abstract. Despite the large number of certificateless encryption schemes recently proposed, many of them have been found to be insecure under a practical attack called malicious-but-passive KGC...
A New Security Definition for Public Key Encryption Schemes and Its Applications (2008)
Guomin Yang, Duncan S. Wong, Qiong Huang, Xiaotie Deng
Abstract. The strongest security definition for public key encryption (PKE) schemes is indistinguishability against adaptive chosen ciphertext attacks (IND-CCA). A practical IND-CCA secure PKE scheme...
Qiong Huang, Guomin Yang, Duncan S. Wong, Willy Susilo
Optimistic fair exchange is a kind of protocols to solve the problem of fair exchange between two parties. Almost all the previous work on this topic are provably secure only in the random oracle...
On secret reconstruction in secret sharing schemes (2008)
Wang, Huaxiong, Wong, Duncan S
A secret sharing scheme typically requires secure communications in each of two distribution phases: (1) a dealer distributes shares to participants (share distribution phase); and later (2) the...
Verifiable Encryption in Anonymous Ad Hoc Groups (2007)
Joseph K. Liu, Victor K. Wei, Duncan S. Wong
Abstract. In a verifiable encryption, an asymmetrically encrypted ciphertext can be publicly verified to be decypherable by a designated receiver without revealing the plaintext. In this paper, we...
Joseph K. Liu, Victor K. Wei, Duncan S. Wong
Abstract. In a veriable encryption, an asymmetrically encrypted ciphertext can be publicly veried to be decipherable by a designated receiver while maintaining the semantic security of the message...
The Design of a rule-based and event-driven trust management framework (2007)
Wang, Yan, Lin, Kwei-Jay, Wong, Duncan S, Varadharajan, Vijay
In both e-commerce (EC) and service-oriented computing (SOC) environments, sellers or service providers interact with customers or service clients for services or transactions. From the point view of...
Generalised cumulative arrays in secret sharing (2006)
Long, Shoulun, Pieprzyk, Josef, Wang, Huaxiong, Wong, Duncan S
Cumulative arrays have played an important role in the early development of the secret sharing theory. They have not been subject to extensive study so far, as the secret sharing schemes built on...
Generalised cumulative arrays in secret sharing (2006)
Long, Shoulun, Pieprzyk, Josef, Wang, Huaxiong, Wong, Duncan S
Cumulative arrays have played an important role in the early development of the secret sharing theory. They have not been subject to extensive study so far, as the secret sharing schemes built on...
Session Corruption Attack and Improvements on Encryption Based MT-Authenticators (2006)
Abstract. Bellare, Canetti and Krawczyk proposed a security model (BCK-model) for authentication and key exchange protocols in 1998. The model not only reasonably captures the power of practical...
Universal custodian-hiding verifiable encryption for discrete logarithms (2006)
Joseph K. Liu, Patrick P. Tsang, Duncan S. Wong, Robertw. Zhu
Abstract. We introduce the notion of Universal Custodian-Hiding Verifiable Encryption (UCH-VE) and propose a scheme of this type for discrete logarithms. A UCH-VE scheme allows an encryptor to...
Further Discussions on the Security of a (2006)
Nominative Signature Scheme, Lifeng Guo, Guilin Wang, Duncan S. Wong
A nominative signature scheme allows a nominator (or signer) and a nominee (or verifier) to jointly generate and publish a signature in such a way that only the nominee can verify the signature and...
ID-Based Ring Signature Scheme secure in the Standard Model (2006)
Man Ho Au, Joseph K. Liu, Y. H. Yuen, Duncan S. Wong
The only known construction of ID-based ring signature schemes which maybe secure in the standard model is to attach certificates to non-ID-based ring signatures. This method leads to schemes that...
Generic Transformation to Strongly Unforgeable Signatures (2006)
Qiong Huang Duncan, Qiong Huang, Duncan S. Wong, Yiming Zhao
Recently, there are two generic transformation techniques proposed for converting unforgeable signature schemes (the message in the forgery has not been signed yet) into strongly unforgeable ones...
Formal Analysis and Systematic Construction of (2006)
Guomin Yang, Duncan S. Wong, Huaxiong Wang, Xiaotie Deng
One of the most commonly used two-factor authentication mechanisms is based on smart card and user's password. Throughout the years, there have been many schemes proposed, but most of them have...
Malicious KGC Attack in Certificateless Cryptography (2006)
Man Ho Au, Jing Chen, Joseph K. Liu, Yi Mu, Duncan S. Wong, Guomin Yang
Identity-based cryptosystems have an inherent key escrow issue, that is, the Key Generation Center (KGC) always knows user secret key. Thus, if the KGC is malicious, it can always impersonate the...
Practical Hierarchical Identity Based Encryption and Signature schemes without Random Oracles (2006)
Man Ho Au, Joseph K. Liu, Tsz Hon Yuen, Duncan S. Wong
In this paper, we propose a Hierarchical Identity Based Encryption scheme that is proven secure under the strongest model of [5] directly, without relying on random oracles. The size of the...
Robert W. Zhu, Xiaojian Tian, Duncan S. Wong
Abstract. In 2001, Canetti and Krawczyk proposed a security model (CKmodel) for authentication protocols. They also gave an indistinguishabilitybased definition for key exchange protocols. Since then...
Abstract A More Efficient Instantiation of Witness-Indistinguishable Signature (2005)
A ring signature or a witness-indistinguishable signature is a setup-free group signature with no group manager. Defined by a set of public keys, a group is created spontaneously without any group...
Improved Efficient Remote User Authentication Schemes Abstract (2005)
Xiaojian Tian, Robert W. Zhu, Duncan S. Wong
Recently, Yoon et al. proposed a new smart card based remote user authentication scheme. We show that this scheme is subject to forgery attacks if the information stored in the smart card is stolen....
Robert W. Zhu, Xiaojian Tian, Duncan S. Wong
Canetti and Krawczyk proposed a security model (CK-model) for authentication and key exchange protocols in 2001 based on a modeling approach proposed by Bellare et al. in 1998. The model not only...
Solutions to Key Exposure Problem in Ring Signature (2005)
In this paper, we suggest solutions to the key exposure problem in ring signature. In particular, we propose the first forward secure ring signature scheme and the first key-insulated ring signature...
A Suite of ID-Based Threshold Ring Signature Schemes with Different Levels of Anonymity (2005)
Man Ho Au, Man Ho Au, Joseph K. Liu, Joseph K. Liu, Patrick P. Tsang, Patrick P. Tsang, ...
Since the introduction of Identity-based (ID-based) cryptography by Shamir in 1984, numerous ID-based signature schemes have been proposed. In 2001, Rivest et al. introduced ring signature that...
Anonymous Signature Schemes (2005)
Guomin Yang, Duncan S. Wong, Xiaotie Deng, Huaxiong Wang
Digital signature is one of the most important primitives in public key cryptography. It provides authenticity, integrity and nonrepudiation to many kinds of applications. On signer privacy however,...
Password Authenticated Key Exchange for Resource-constrained Wireless Communications ⋆ (2005)
Duncan S. Wong, Agnes H. Chan, Feng Zhu
Abstract. With the advancement of wireless technology and the increasing demand for resource-constrained mobile devices, secure and efficient password authenticated key exchange (PAKE) protocols are...
Security Analysis of Two Anonymous Authentication Protocols for Distributed Wireless Networks (2005)
In a set of distributed wireless networks, such as globally distributed cellular systems, different networks could be administered by different operators. Mobile devices subscribed to one network may...
Linkable spontaneous anonymous group signature for ad hoc groups (extended abstract (2004)
Joseph K. Liu, Victor K. Wei, Duncan S. Wong
Abstract. We present a linkable spontaneously anonymous group (LSAG) signature scheme (alternatively known as linkable ring signature scheme) satisfying the following three properties. (1) Anonymity,...
Separable linkable threshold ring signatures (2004)
Patrick P. Tsang, Victor K. Wei, Tony K. Chan, Man Ho Au, Joseph K. Liu, Duncan S. Wong
Abstract. A ring signature scheme is a group signature scheme with no group manager to setup a group or revoke a signer. A linkable ring signature, introduced by Liu, et al. [20], additionally allows...
Separable Linkable Threshold Ring Signatures (2004)
Patrick P. Tsang, Victor K. Wei, Tony K. Chan, Man Ho Au, Joseph K. Liu, Duncan S. Wong
A ring signature scheme is a group signature scheme with no group manager to setup a group or revoke a signer. A linkable ring signature, introduced by Liu, et al. [20], additionally allows anyone to...
Separable linkable threshold ring signatures (2004)
Patrick P. Tsang, Victor K. Wei, Tony K. Chan, Man Ho Au, Joseph K, Duncan S. Wong
Abstract. A ring signature scheme is a group signature scheme with no group manager to setup a group or revoke a signer. A linkable ring signature, introduced by Liu, et al. [20], additionally allows...
Linkable and anonymous signature for ad hoc groups (2004)
Joseph K. Liu, Victor K. Wei, Duncan S. Wong
Abstract. We present a 1-out-of-n group signature scheme that satisfies three major properties. (1) Anonymity, or signer-indistinguishability. (2) Linkability: That two signatures by the same signer...
Password Authenticated Key Exchange based on RSA for Imbalanced Wireless Network (2002)
Feng Zhu, Duncan S. Wong, Agnes H. Chan, Robbie Ye
1 Introduction Classical symmetric key based authenticated key exchange protocols dictate the shared cryptographic keys to be long enough and randomly generated so that they can deter key-guessing...
The Performance Measurement of Cryptographic Primitives on Palm Devices (2001)
Duncan S. Wong, Hector Ho Fuentes, Agnes H. Chan
We developed and evaluated several cryptographic system libraries for Palm OS £ which include stream and block ciphers, hash functions and multiple-precision integer arithmetic operations. We noted...