Digital signatures whose security does not rely on any unproven computational assumption have recently received considerable attention. While these unconditionally secure digital signatures provide a foundation for long term integrity and non-repudiation of data, currently known schemes generally require a far greater amount of memory space for the storage of users’ secret information than a tr...

Information theoretic cryptography is discussed based on conditional Rényi entropies. Our discussion focuses not only on cryptography but also on the definitions of conditional Rényi entropies and the related information theoretic inequalities. First, we revisit conditional Rényi entropies, and clarify what kind of properties are required and actually satisfied. Then, we propose security criter...

In SCN2010, Gagné, Narayan, and Safavi-Naini proposed attribute-based signcryption (ABSC) with threshold structure. As in ciphertext-policy attribute-based encryption (CP-ABE), an encryptor can specify the access structure of decryptors, and as in attribute-based signature (ABS), each decryptor can verify the encryptor’s attributes. In contrast to the access structure of decryptors, the access ...

This paper presents an ongoing work toward the proposal of the new concept of the attribute-based cryptosystem. In SCN2010, Gagné, Narayan, and Safavi-Naini proposed attribute-based signcryption (ABSC) with threshold structure. As in ciphertext-policy attribute-based encryption (CP-ABE), an encryptor can specify the access structure of decryptors, and as in attribute-based signature (ABS), each...

A successful endodontic treatment depends on appropriate instrumentation, irrigation, decontamination and obturation. Chemomechanical instrumentation removes majority of the infecting bacteria, but this is not achieved completely because of complex root canal anatomy and limitation in accessing the root canal system (Manzur et al., 2007). Persistent endodontic infection might be attributed to t...

semantic shifting which is one of the most important semantic processes forming the meaning of some linguistic structures was first introduced by safavi (1379). the meaning of different structures such as proverbs, are made by semantic shifting which takes place on the syntagmatic axis, but is shown on the paradigmatic axis. the corpus used in this study consists of 10 persian proverbs which ar...

Unconditionally secure authentication codes provide information theoretic security against an adversary who observes authenticated messages and then wants to construct a fraudulent message that is acceptable by the receiver. The attack model for these codes has recently been strengthened and adaptive adversaries with oracle access have been introduced. In this paper we give an analysis of this ...

the safavid dynasty was the first iranian centralized administration, which chose shia’a branch of islam as the official religion and the judicial system for iran. in safavi period the state officially established two separate and distinct court system. first the state courts (the urf courts) under the supervision of the secular minister of justice (divan-begi) and the secondly the islamic cour...