Structural Identity-Based Encryption (2008)
Abstract. In this paper, we introduce the concept of structural identitybased encryption (SIBE). Similar to hierarchical identity-based encryption (HIBE), entities in the system are organized into...
(Convertible) Undeniable Signatures without Random Oracles (2008)
Tsz Hon Yuen, Man Ho Au, Joseph K. Liu, Willy Susilo
Abstract. We propose a convertible undeniable signature scheme without random oracles. Our construction is based on Waters ’ and Kurosawa and Heng’s schemes that were proposed in Eurocrypt 2005....
(Convertible) Undeniable Signatures without Random Oracles (2008)
Tsz Hon Yuen, Man Ho Au, Joseph K. Liu, Willy Susilo
Abstract. We propose a convertible undeniable signature scheme without random oracles. Our construction is based on Waters ' and Kurosawa and Heng's schemes that were proposed in Eurocrypt...
Practical anonymous divisible e-cash from bounded accumulators (2008)
Man Ho Au, Willy Susilo, Yi Mu
Abstract. We present an efficient off-line divisible e-cash scheme which is truly anonymous without a trusted third party. This is the second scheme in the literature which achieves full...
BLAC: Revoking Repeatedly Misbehaving Anonymous Users Without Relying on TTPs ∗ (2008)
Patrick P. Tsang, Man Ho Au, Apu Kapadia, Sean W. Smith
Several credential systems have been proposed in which users can authenticate to service providers anonymously. Since anonymity can give users the license to misbehave, some variants allow the...
Blacklistable anonymous credentials: Blocking misbehaving users without TTPs (2007)
Patrick P. Tsang, Man Ho Au, Apu Kapadia, Sean W. Smith
Several credential systems have been proposed in which users can authenticate to services anonymously. Since anonymity can give users the license to misbehave, some variants allow the selective...
Self-Generated-Certificate Public Key Cryptography and (2007)
Certificateless Signature Encryption, Joseph K. Liu, Man Ho Au, Willy Susilo
Certificateless Public Key Cryptography (CL-PKC) enjoys a number of features of Identity-Based Cryptography (IBC) while without having the problem of key escrow. However, it does su#er to an attack...
Blacklistable anonymous credentials: Blocking misbehaving users without TTPs (2007)
Patrick P. Tsang, Man Ho Au, Apu Kapadia, Sean W. Smith
Several credential systems have been proposed in which users can authenticate to services anonymously. Since anonymity can give users the license to misbehave, some variants allow the selective...
Practical compact e-cash (2007)
Man Ho Au, Willy Susilo, Yi Mu
Abstract. Compact e-cash schemes allow a user to withdraw a wallet containing k coins in a single operation, each of which the user can spend unlinkably. One big open problem for compact e-cash is to...
Blacklistable anonymous credentials: Blocking misbehaving users without TTPs (2007)
Patrick P. Tsang, Man Ho Au, Apu Kapadia, Sean W. Smith
Several credential systems have been proposed in which users can authenticate to services anonymously. Since anonymity can give users the license to misbehave, some variants allow the selective...
Blacklistable anonymous credentials: Blocking misbehaving users without TTPs (2007)
Patrick P. Tsang, Man Ho Au, Apu Kapadia, Sean W. Smith
Several credential systems have been proposed in which users can authenticate to services anonymously. Since anonymity can give users the license to misbehave, some variants allow the selective...
Short linkable ring signatures revisited (2006)
Man Ho Au, Willy Susilo, Patrickp. Tsang
Abstract. Ring signature is a group-oriented signature in which the signer can spontaneously form a group and generate a signature such that the verifier is convinced the signature was generated by...
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...
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...
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...
PEREA: Towards practical TTP-free revocation in anonymous authentication (2005)
Patrick P. Tsang, Man Ho Au, Apu Kapadia, Sean W. Smith
Several anonymous authentication schemes allow servers to revoke a misbehaving user’s ability to make future accesses. Traditionally, these schemes have relied on powerful TTPs capable of...
PEREA: Towards practical TTP-free revocation in anonymous authentication (2005)
Patrick P. Tsang, Man Ho Au, Apu Kapadia, Sean W. Smith
Several anonymous authentication schemes allow servers to revoke a misbehaving user’s ability to make future accesses. Traditionally, these schemes have relied on powerful TTPs capable of...
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...
ID-based Cryptography from Composite Degree Residuosity (2004)
We present identity-based identification (resp. encryption, signature, blind signature, ring signature) from composite degree residuosity (CDR). Constructions of identifications and signatures...
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...