There are many cryptographic schemes with anonymity, such as group signatures. As one important property, anonymity revocation has been introduced. In such schemes, the fact of whether a signer’s rights have been revoked or not is important additional information. For example, if a third party knows that there are many revoked members in a company, then the company’s reputation may be damaged i...

An authenticated encryption allows the specific recipient to verify the authenticity while recovering the message. To protect the recipient’s interest in case of a later dispute, a convertible authenticated encryption scheme allows the specific recipient to retrieve an authenticated cipher text and convert the authenticated ciphertext into an ordinary signature so that it becomes publicly verif...

Identity based cryptosystem simplifies the key management and revocation problem. Here we propose an Identity Based Strong Designated Verifier Signature (IBSDVS) scheme using bilinear pairings. The Designated Verifier Signature scheme described in [10] is identity based but it suffers from the deligatability as pointed out in [4]. We analyse the security of the scheme and show that the problem ...

In a designated verifier signature (DVS) scheme a signer creates a signature which is only verifiable by a designated verifier. A DVS is a useful scheme for authenticating a signer without disturbing her privacy. In a universal DVS (UDVS) scheme, everyone who holds Alice’s traditional signature on a message (the signature holder), is able to transform it to a DVS for a specific verifier. Non-de...

random oracles Bin Wang and Qing Zhao Information Engineering College of Yangzhou University No.196 West HuaYang Road, Yangzhou City, Jiangsu Province, P.R.China E-mail: [email protected] Abstract: Server-aided verification(SAV) signature is useful for power-constrained devices since a powerful server can assist in performing costly operations such as pairing operations. Wu et al. [13] defined t...

Computer networks bring tremendous progress to the information-based society. Companies, organizations, and governments have been using computers and networks to process or transmit digital data. But this also results in many different types of security requirements for group-oriented cryptographic applications. In this thesis we study existing cryptographic tools and then use them to design mo...

Motivated by privacy issues associated with dissemination of signed digital certificates, we definea new type of signature scheme called a ‘Universal Designated-Verifier Signature’ (UDVS). A UDVSscheme can function as a standard publicly-verifiable digital signature but has additional functional-ity which allows any holder of a signature (not necessarily the signer) to designate the...