At ISW’99, Nishioka, Hanaoka and Imai proposed a digital signature scheme on ID-based key-sharing infrastructures. That signature scheme is claimed to be secure if the discrete logarithm problem is hard to solve. Two schemes (the ID-type and the random-type schemes) based on the linear scheme for the Key Predistribution Systems (KPS) and the discrete logarithm problem (DLP) were given. In this ...

Designated verifier signature schemes allow a signer to convince only the designated verifier that a signed message is authentic. We define attack models on the unforgeability property of such schemes and analyze relationships among the models. We show that the no-message model, where an adversary is given only public keys, is equivalent to the model, where an adversary has also oracle access t...

The strong designated verifier ring signature scheme provides signer anonymity to protect actual signer’s identity. However, the message of the strong designated verifier ring signature may disclose some identity information related to the actual signer. To remove this flaw, this study proposes a novel strong designated verifier ring signcryption scheme. Compared with the Han et al. and Huang e...

In this paper, adapting a novel dual authentication method based on smart cards in public networks is proposed. This method uses the ElGamal public key cryptosystem and extend Chaum–van Antwerpen’s scheme to authenticate a signature between the signer and verifier using a dual protocol with a smart card that has tamper-resistant features. We propose the method to change the verification and dis...

A new concept of society-oriented designated confirmer signatures (SDCS) is introduced in this paper. SDCS is well suited to applications where the capability of the signer and that of the confirmer are both expected to be shared among a group of individuals. The ways to share the signing capability and the confirming capability are different due to the distinct stabilities of the signer group ...

Directed signature scheme allows only a designated verifier to check the validity of the signature issued to him; and at the time of trouble or if necessary, any third party can verify the signature with the help of the signer or the designated verifier as well. Due to its merits, directed signature scheme is widely used in situations where the receiver’s privacy should be protected. Threshold ...

The concept of universal designated verifier signatures was introduced by Steinfeld, Bull, Wang and Pieprzyk at Asiacrypt 2003. These signatures can be used as standard publicly verifiable digital signatures but have an additional functionality which allows any holder of a signature to designate the signature to any desired verifier. This designated verifier can check that the message was indee...

In this paper, we propose a new approach for constructing selectively convertible undeniable signature schemes, and present two efficient schemes based on RSA. Our approach allows a more direct selective conversion than the previous schemes, and the security can be proved formally. Further, our disavowal protocols do not require parallelization techniques to reach a significant soundness probab...

Designated verifier signature (DVS) allows the signer to persuade a verifier the validity of a statement but prevent the verifier from transferring the conviction. Strong designated verifier signature (SDVS) is a variant of DVS, which only allows the verifier to privately check the validity of the signer’s signature. In this work we observe that the unforgeability model considered in the existi...