In this paper, we describe an attack on a new double block length Hash Function which was proposed as a variant of MDC-2 and MDC-4. The vMDC-2 compression Function is based on two calls to a block cipher that compresses a 3n-bit string to a 2n-bit one. This attack is based on the Joux's multicollision attack, where we show that an adversary wins finding collision game by requesting 270 queries for n=128-bit block cipher that is much less than the complexity of birthday attack.

Recently, there has been a surge in the popularity of cryptocurrencies, which are digital currencies that enable transactions through a decentralized consensus mechanism. In this paper, one of the most effective EquiHash algorithms subcategories, known as BLAKE2, is presented, and then effort has been made to optimize the compression Function as one of the main and most challenging blocks of the BLAKE2 algorithm. In addition, by cognitive partitioning the algorithm between the software/hardware parts of the device, efforts have been made to improve the speed and the number of resource usage. For comparison, implementation was carried out with high-level vs HDL design methods for full and semi-parallel structures. All three methods were implemented using Vivado tools exploiting ZC706 evaluation board. The implementation results indicated that the number of resource usage (LUT/FF) and power consumption of the proposed structure is equal to (6575/4726) and 0. 316(W) respectively Which has created a significant reduction compared to other methods. Moreover, the Hash rate and the energy efficiency of the proposed structure are equal to 50 MHash/s and 6. 3 (𝑛𝐽/𝐻𝑎𝑠ℎ) respectively

Nowadays, as tampering attacks getting more attention, data protection Radio Frequency Identification tag (RFID) becomes more important. The watermarking approach prevents unauthorized changes on the content of such labels. Due to the limitations of such tags like their simple structure, scarcity of memory bits and its binary content, using conventional methods likes watermarking and Hash Function are impossible. Thus, the approaches that can be applied to binary data with low size are used. This paper is based on a special algorithm of neural networks that is used to create the Hash and the watermarking code that causes fewer number of valuable bits of memory to be consumed. In the proposed algorithm, all watermarking bits are securely protected and locations of the watermark bits is not detectable. This method not only has no need for secrecy watermarking algorithms, but also has other benefits such as ease and speed of implementation. Another advantage of the proposed approach is the two-step algorithm with its keys and using pseudo-random bits location makes watermark's probability of detection very difficult and inaccessible, and also increase the robustness of the method.

Hash Functions have a very important role in network and telecommunication security. These Functions play an important role in Hashing a message which are widely used in cryptographic applications such as digital signatures, random number generator algorithms, authentication protocols, and so on. Rotational cryptanalysis is a relatively new attack that is part of a generic attack on Hash Functions and is effective on algorithms that have an ARX structure. In this paper, for the first time, we apply a rotational cryptanalysis and with the given assumption of the markov chain for the modular additions sequence employed in two algorithms Shabal and CubeHash, which are second-round candidates for the SHA-3 competition that use the ARX property in their structure. With the implementation of rotational cryptanalysis we arrived at the complexity of 2-3393. 58 for the entire 16+3-rounds Shabal algorithm and the complexity of 2-57. 6 for the en-tire 16-round CubeHash algorithm. According to the obtained results, it can be seen that due to the large number of modular additions with the given assumption of markov chain, the Shabal algorithm exhibits greater resistance to rotational cryptanalysis, compared to the CubeHash algorithm and is less likely to succeed.

Background and Objectives: Cryptographic Hash Functions are the linchpins of mobile services, blockchains, and many other technologies. Designing cryptographic Hash Functions has been approached by research communities from the physics, mathematics, computer science, and electrical engineering fields. The emergence of new Hash Functions, new Hash constructions, and new requirements for application-specific Hash Functions, such as the ones of mobile services, have encouraged us to make a comparison of different Hash Functions and propose a new classification.Methods: Over 100 papers were surveyed and reviewed in detail. The research conducted in this paper has included four sections; article selection, detailed review of selected articles, data collection, and evaluation of results. Data were collected as new Hash Function properties, new Hash Function constructions, new Hash Function categories, and existing Hash Function attacks which are used to evaluate the results.Results: This paper surveys seven categories of Hash Functions including block cipher-based Functions, algebraic-based Functions, custom-designed Functions, Memory-hard Functions (MHFs), Physical Unclonable Functions (PUFs), quantum Hash Functions and optical Hash Functions. To the best of our knowledge, the last four mentioned categories have not been sufficiently addressed in most existing surveys. Furthermore, this paper overviews Hash-related adversaries and six Hash construction variants. In addition, we employed the mentioned adversaries as evaluation criteria to illustrate how different categories of Hash Functions withstand the mentioned adversaries. Finally, the surveyed Hash Function categories were evaluated against mobile service requirements.Conclusion: In addition to new classification, our findings suggest using PUFs with polynomial-time error correction or possibly bitwise equivalents of algebraic structures that belongs to post-quantum cryptography as candidates to assist mobile service interaction requirements.

An essential Function for achieving security in computer networks is the reliable authentication of communicating parties and network components. Such authentication typically relies on the exchanges of cryptographic messages between the involved parties, which imply that these parties are able to acquire shared secret keys by means of a key distribution protocol. Provision of authentication and key distribution Functions in the primitive and resource constrained environments such as low-level networking mechanisms, portable, and wireless devices presents challenge in terms of resource usage, system management, ease of use and efficiency, that are beyond the capabilities of previous designs such as Kerberos or X509. The lack of capability arises from the fact that these protocols use the conventional algorithms (such as DES and RSA) with large amount of cryptographic processing and message size. This paper presents a lightweight authentication and key distribution protocol. It is a minimum protocol (in term of message number, rounds number, message length, encryption computation, storage usage and so on). The protocol is suitable and acts more efficient in the low layers of computer network, mobile units and small portable computers.

Deterministic measurement matrices have a crucial character in compressive sensing (CS) applications. These matrices can be generated randomly and deterministically. Due to less memory needed for storage, deterministic matrices have been taken into consideration vastly rather than random ones. In this paper, by use of Hash Functions (HF), a group of new measurement matrices has been presented. For this purpose, first, a primary matrix of code is generated then by use of Hash matrices a new matrix is produced.Finally by normalizing the new matrix elements, measurement matrix will be generated. Through this construction, a group of measurement matrices with size of p 2 ´ p 3 and coherence coefficient equal to1 p, where p is a prime integer, will be obtained.Simulation results illustrate that for low values of p, proposed matrices slightly outweigh BCH sampling matrices.

By exploiting symmetries of finite fields, covering perfect Hash families provide a succinct representation for covering arrays of index one. For certain parameters, this connection has led to both the best current asymptotic existence results and the best known efficient construction algorithms for covering arrays. The connection generalizes in a straightforward manner to arrays in which every $t$-way interaction is covered $\lambda > 1$ times, i.e., to covering arrays of index more than one. Using this framework, we focus on easily computed, explicit upper bounds on numbers of rows for various parameters with higher index.

A cryptographic Hash Function maps an arbitrary length input to a fixed length output. These Functions are used in many cryptographic applications such as digital signatures. They must be secure against collision, preimage and 2-preimage attacks. Rotational cryptanalysis is an approach to the analysis of ARX ciphers. The Hash Functions Shabal and CubeHash, which are two candidates of the second round of the SHA-3 competition, have an ARX structure. They have been analyzed with respect to rotational cryptanalysis by Tabatabaei et al. In this paper we consider their analysis and present some observations. Our observations show that the results of Tabatabaei et al. ’ s cryptanalysis are not accurate. Then we present some new results about rotational cryptanalysis of Shabal and CubeHash. Thereafter we present some new results and show that rotational cryptanalysis is effective on a smaller number of rounds on Shabal and CubeHash Hash Functions.