Sharif Digital Repository

Cryptographic algorithms utilize finite-field arithmetic operations in their computations. Due to the constraints of the nodes which benefit from the security and privacy advantages of these algorithms in sensitive applications, these algorithms need to be lightweight. One of the well-known bases used in sensitive computations is dual basis (DB). In this brief, we present low-complexity superserial architectures for the DB multiplication over GF (2m). To the best of our knowledge, this is the first time that such a multiplier is proposed in the open literature. We have performed complexity analysis for the proposed lightweight architectures, and the results show that the hardware complexity... 

Nowadays low-cost RFID systems have moved from obscurity into mainstream applications which cause growing security and privacy concernsThe lightweight cryptographic primitives and authentication protocols are indispensable requirements for these devices to grow pervasiveIn recent years, there has been an increasing interest in intuitive analysis of RFID protocolsThis concept has recently been challenged by formal privacy modelsThis paper investigates how to analyse and solve privacy problems in formal modelFirst, we highlight some vague drawbacks especially in forward and backward traceability analysis and extend it in the simulation-based privacy model familyThen, the privacy weaknesses of... 

A specific class of differential cryptanalytic approach, known as Related Key Boomerang Attack, has been successfully applied to several symmetric cryptographic primitives in particular encryption schemes such as Advanced Encryption Standard (AES). In this paper, we propose a new related-key boomerang attack on 8-round AES-256, a couple of ones on 9-round following the work of Gorski et al. In the first one, we attacked 8-round AES-256 with the time complexity of 279 and the data complexity of 259. The extended 8-round attack on 9-round AES-256 is more efficient than previous attacks from both time and data complexity perspectives  

A specific class of differential cryptanalytic approach, named as impossible differential attack, has been successfully applied to several symmetric cryptographic primitives in particular encryption schemes such as Advanced Encryption Standard (AES). Such attacks exploit differences that are impossible at some intermediate state of the cipher algorithm. The best-known impossible differential attack against AES-128 has applied to six rounds. An attack on AES-128 up to seven rounds is proposed. The proposed attack requires 2115.5 chosen plaintexts and 2109 bytes of memory and performs 2119 seven-round AES encryptions. This is also the best-known attack on a reduced version of the AES-128 till... 

The Internet of Things (IoT) presents a new paradigm of the future Internet that intends to provide interactive communication between various processing objects via heterogeneous networks. The IPv6 over Low power Wireless Personal Area Networks (6LoWPAN) is an IPv6 adaptation sub-layer and provides the requirements of IP connectivity between resource-constrained devices in lossy, low power networks. Since the size of a packet in the IPv6 is larger than the size of a frame in the IEEE 802.15.4, the 6LoWPAN adaptation layer performs packet fragmentation. In this paper, first, the 6LoWPAN fragmentation mechanism in terms of security issues is analyzed and then, fragment duplication attack which... 

Numerous authentication protocols for RFID systems were proposed as attempt to prevent unauthorized tracking and monitoring, impersonation or cloning, and information leakage. Many of such attempts cannot establish essential requirements that one robust authentication protocol must guarantee. In this paper, we propose a rapid mutual authentication protocol, called FLMAP, that overcomes all the drawbacks of previously proposed protocols. Our protocol has three passes and it does not use any cryptographic primitives such as hash functions and encryption algorithms; it is very fast and efficient. Significant characteristics of the protocol are forward security, tag anonymity, location privacy,...