In a proxy signature scheme, a user delegates his/her signing capability to another user in such a way that the latter can sign messages on behalf of the former. In this paper, we first propose a provably secure proxy signature scheme, which is based on a two-party Schnorr signature scheme. Then, we extend this basic scheme into designated-verifier proxy signatures (DVPS). More specifically, we...

Multi-Designated Verifier Signatures (MDVS) are privacy-oriented signatures that can only be verified by a set of users specified by the signer. We propose two new generic constructions of MDVS from variants of existing cryptographic schemes, which are ring signature from anonymous subset and multi-chameleon hash. We first devise a single add-on protocol which enables many existing identity-bas...

We give a generic construction for universal designated-verifier signature schemes from a large class, C, of signature schemes. The resulting schemes are efficient and have two important properties. Firstly, they are provably DV-unforgeable, non-transferable and also non-delegatable. Secondly, the signer and the designated verifier can independently choose their cryptographic settings. We also ...

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 In such schemes, the fact of whether a signer’s rights have been revoked or not is important additional information.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...

Although patients frequently express a preference for oral medications, compliance to these medications varies. Patients often have difficulty adhering to their medication schedules due to lack of understanding, inadequate support, or unwelcome side effects. Fostering adherence to oral chemotherapy regimens improves patients' chance of survival and long-term quality of life. This randomized tri...

The objective of this study was to examine the information provided on comprehensive cancer centers' Web sites regarding clinical trials. Thirty-nine Web sites were visually inspected for four categories of variables: navigation to the clinical trial information, search functionality provided to the visitor, information content provided about trials, and the reading level of the information pro...

There is a signature scheme which can aggregate two or more persons’ signatures to one, called an aggregate signature. In this paper, we propose a scheme of an aggregate signature which has additional functionality allowing any holder of a signature to designate the signature to any desired designated-verifier. By this functionality, no one other than the designated-verifier can verify the sign...

ecological classification of the coastal zone, have recently been using the “biotope” as a unit. lexically “biotope” is synonymous with habitat, but with different ecological concepts. various biotopes in 122 km intertidal stretch of the southern coasts of the qeshm island (qeshm city in east to dustaku village in west) in four seasons were identified and mapped out (2009-2010). considering the...