Differential Analysis of Block Ciphers SIMON and SPECK

In this paper we continue the previous line of research on the analysis of the differential properties of the lightweight block ciphers Simon and Speck. We apply a recently proposed technique for automatic search for differential trails in ARX ciphers and improve the trails in Simon32 and Simon48 previously reported as best. We further extend the search technique for the case of differen- tials and improve the best previously reported differentials on Simon32, Simon48 and Simon64 by exploiting more effectively the strong differential effect of the cipher. We also present improved trails and differentials on Speck32, Speck48 and Speck64. Using these new results we improve the currently best known attacks on several versions of Simon and Speck. A second major contribution of the paper is a graph based algorithm (linear time) for the computation of the exact differential probability of the main building block of Simon: an AND operation preceded by two bitwise shift operations. This gives us a better insight into the differential property of the Simon round function and differential effect in the cipher. Our algorithm is general and works for any rotation constants. The presented techniques are generic and are therefore applicable to a broader class of ARX designs

A Security Analysis of IoT Encryption: Side-channel Cube Attack on Simeck32/64

Simeck, a lightweight block cipher has been proposed to be one of the encryption that can be employed in the Internet of Things (IoT) applications. Therefore, this paper presents the security of the Simeck32/64 block cipher against side-channel cube attack. We exhibit our attack against Simeck32/64 using the Hamming weight leakage assumption to extract linearly independent equations in key bits. We have been able to find 32 linearly independent equations in 32 key variables by only considering the second bit from the LSB of the Hamming weight leakage of the internal state on the fourth round of the cipher. This enables our attack to improve previous attacks on Simeck32/64 within side-channel attack model with better time and data complexity of 2^35 and 2^11.29 respectively.Comment: 12 pages, 6 figures, 4 tables, International Journal of Computer Networks & Communication

A Survey of ARX-based Symmetric-key Primitives

Addition Rotation XOR is suitable for fast implementation symmetric –key primitives, such as stream and block ciphers. This paper presents a review of several block and stream ciphers based on ARX construction followed by the discussion on the security analysis of symmetric key primitives where the best attack for every cipher was carried out. We benchmark the implementation on software and hardware according to the evaluation metrics. Therefore, this paper aims at providing a reference for a better selection of ARX design strategy

Lightweight Architectures for Reliable and Fault Detection Simon and Speck Cryptographic Algorithms on FPGA

The widespread use of sensitive and constrained applications necessitates lightweight (lowpower and low-area) algorithms developed for constrained nano-devices. However, nearly all of such algorithms are optimized for platform-based performance and may not be useful for diverse and flexible applications. The National Security Agency (NSA) has proposed two relatively-recent families of lightweight ciphers, i.e., Simon and Speck, designed as efficient ciphers on both hardware and software platforms. This paper proposes concurrent error detection schemes to provide reliable architectures for these two families of lightweight block ciphers. The research work on analyzing the reliability of these algorithms and providing fault diagnosis approaches has not been undertaken to date to the best of our knowledge. The main aim of the proposed reliable architectures is to provide high error coverage while maintaining acceptable area and power consumption overheads. To achieve this, we propose a variant of recomputing with encoded operands. These low-complexity schemes are suited for lowresource applications such as sensitive, constrained implantable and wearable medical devices. We perform fault simulations for the proposed architectures by developing a fault model framework. The architectures are simulated and analyzed on recent field-programmable grate array (FPGA) platforms, and it is shown that the proposed schemes provide high error coverage. The proposed low-complexity concurrent error detection schemes are a step forward towards more reliable architectures for Simon and Speck algorithms in lightweight, secure applications

Mind the Gap - A Closer Look at the Security of Block Ciphers against Differential Cryptanalysis

Resistance against differential cryptanalysis is an important design criteria for any modern block cipher and most designs rely on finding some upper bound on probability of single differential characteristics. However, already at EUROCRYPT'91, Lai et al. comprehended that differential cryptanalysis rather uses differentials instead of single characteristics. In this paper, we consider exactly the gap between these two approaches and investigate this gap in the context of recent lightweight cryptographic primitives. This shows that for many recent designs like Midori, Skinny or Sparx one has to be careful as bounds from counting the number of active S-boxes only give an inaccurate evaluation of the best differential distinguishers. For several designs we found new differential distinguishers and show how this gap evolves. We found an 8-round differential distinguisher for Skinny-64 with a probability of 2−56.932−56.93, while the best single characteristic only suggests a probability of 2−722−72. Our approach is integrated into publicly available tools and can easily be used when developing new cryptographic primitives. Moreover, as differential cryptanalysis is critically dependent on the distribution over the keys for the probability of differentials, we provide experiments for some of these new differentials found, in order to confirm that our estimates for the probability are correct. While for Skinny-64 the distribution over the keys follows a Poisson distribution, as one would expect, we noticed that Speck-64 follows a bimodal distribution, and the distribution of Midori-64 suggests a large class of weak keys

A new intelligent hybrid encryption algorithm for IoT data based on modified PRESENT-Speck and novel 5D chaotic system

Modern application based on IoT sensors/devices are growth in several fields. In several cases, the sensing data needs to be secure in transmission to control / administrator side. In this paper, the proposed secure Internet of Things data sensing and proposed algorithms will be explained, based on the main overarching novel 5-D Hyper chaotic system and new encryption mechanisms (contains hybrid encryption and two modified encryption algorithms) controlled by Fuzzy rules. The encryption mechanism combined by using the structure of PRESENT and SPECK algorithm with novel 5-D chaotic system. Also, for encryption will use the modified mechanisms of Round steps in PRESENT algorithm by SPEECK which were adopted on an IoT sensing data transferring. This proposed system provides a high level of security for any sensitive information that may be generated from sensors that may be installed in an important location to protect buildings and offices from theft by making certain modifications to the algorithms necessary to maintain the safety and security of the information, etc., which must be protected from Attacks. This system is designed to be effective in providing security features for data contents that include confidentiality, authentication and non-repudiation, and is compatible with all types of remote sensing data and sensors to send the final notification to the final administrator view. The proposed system is designed to provide users with high flexibility and ease in managing change operations, speeding up encryption operations and intruding the contents of message packets (types and forms of different sensor data) at the point of origin and decrypting and checking packet integrity messages upon receipt. These features make users of this system more confident with each other. The proposed encryption mechanism and novel chaotic system passed different testes. The generated chaos key space at least 22560probable different combinations of the secret keys to break the system used brute force attack

Security in 1-wire system : case study : Home automation /

La automatización de viviendas es un campo de la tecnología que siempre se encuentra en crecimiento, desarrollando sistemas que reducen los costos de los dispositivos. Por esto, se ha logrado que la domótica esté al alcance de todos. Desde la aparición de productos que permiten crear tu propio sistema domótico, y la reciente popularidad que ha tenido el Internet de las cosas (IoT), la industria de la automatización de viviendas ha cambiado mucho. Tener la habilidad de controlar dispositivos a través de Internet crea numerosas vulnerabilidades al sistema, permitiendo a un atacante controlar y ver todo lo que ocurre. En este trabajo se estudia un sistema domótico que usa 1-wire como protocolo de comunicación. Originalmente, el sistema carece de seguridad. Nuestro objetivo es implementar seguridad de la información a través de la encriptación de los comandos del sistema, para así poder proveer Confidencialidad, Integridad y Disponibilidad (CIA). Los resultados muestran no sólo la implementación exitosa del módulo criptográfico dentro del sistema domótico para proveer seguridad, sino que también se demuestra que añadir este proceso no afectaría el modo en que el usuario maneja sus dispositivos.Incluye referencias bibliográfica