Recently, Chien et al. proposed an efficient timestampbased remote user authentication scheme using smart cards. The main merits include: (1) user-independent server, i.e., there is no password or verification table kept in the server; (2) users can freely choose their passwords; (3) mutual authentication is provided between the user and the server; and (4) lower communication and computation c...

based on a general rule in civil liability, external causes limits or excludes the liability of defendant. however, the question is that whether it is possible to applied the general rule when there are compulsory liability insurances? this paper is intended to study the subject-matter regarding traffic accidents (as one of the anticipated cases of compulsory insurances) in iranian and french l...

Two effective attacks, namely de-synchronization attack and impersonation attack, against Ha et al. ’s LCSS RFID authentication protocol, Song and Mitchell’s protocol are identified. The former attack can break the synchronization between the RFID reader and the tag in a single protocol run so that they can not authenticate each other in any following protocol run. The latter can impersonate a ...

Digital signatures are necessary wherever legal certainty is to be achieved for digital message exchange. However, the unforgeability of conventional digital signatures is necessarily based on complexity theoretic assumptions. That is, even the most secure schemes can be broken by an adversary with unexpected computing abilities, e.g., one who can factor unexpectedly large numbers. Fail-stop si...

General method of side-channel attacks protection, based on random cipher isomorphisms is presented. Isomorphic ciphers produce common outputs for common inputs. Cipher isomor-phisms can be changed independently on transmitting and receiving sides. Two methods of RIJNDAEL protection are considered. The first one is based on random commutative isomor-phisms of underlying structure. The set of fi...

Security of an encryption system is formally established through the properties of an abstract game played between a challenger and an adversary. During the game, the adversary will be provided with all information that he could obtain in an attack model so that the adversary is fully empowered to carry out the break. The information will be provided to the adversary through the answers of appr...

law department, ferdowsi university of mashhad the importance of the exploitation contracts protecting the literary and artistic rights has, in some legal systems like france, resulted in the devising of general and common regulations about the formation of the above-mentioned contracts. however, so far no independent section has been thought of in the iranian legal system for explicating commo...