Evaluation of Lightweight Block Ciphers in Hardware Implementation: A Comprehensive Survey

Evaluation of Lightweight Block Ciphers in Hardware Implementation: A Comprehensive Survey

Jaber Hossein Zadeh Data and Communication Security Laboratory (DCSL) Faculty of Engineering, Ferdowsi University of Mashhad
Mashhad, Iran Jaber_hosseinzadeh@stu-mail.um.ac.ir

Abbas Ghaemi Bafghi Data and Communication Security Laboratory (DCSL) Department of Computer Engineering, Faculty of Engineering ,Ferdowsi University of Mashhad
Mashhad, Iran Ghaemib@um.ac.ir

Abstract— The conventional cryptography solutions are ill-suited to strict memory, size and power limitations of resource- constrained devices, so lightweight cryptography solutions have been specifically developed for this type of applications. In this domain of cryptography, the term lightweight never refers to inadequately low security, but rather to establishing the best balance to maintain sufficient security. This paper presents the first comprehensive survey evaluation of lightweight block ciphers in terms of their speed, cost, performance, and balanced efficiency in hardware implementation, and facilitates the comparison of studied ciphers in these respects. The cost of lightweight block ciphers is evaluated with the metric of Gate Equivalent (Fig.1), their speed with the metric of clock-cycle-per- block (Fig.2), their performance with the metric of throughput (Fig.3) and their balanced efficiency with the metric of Figure of Merit (Fig.4). The results of these evaluations show that SIMON, SPECK, and Piccolo are the best lightweight block ciphers in hardware implementation.(Abstract) Keywords— lightweight block cipher, hardware implementation, balanced efficiency, cost criterion, performance criterion, speed criterion, Figure Of Merit, clock cycle per block, Gate Equivalent Introduction Lightweight cryptography has been developed specifically for low-cost resource-constrained devices, as its design allows it work with limited hardware. Devices used in wireless sensor networks, RFID tags, and Internet of things (IoT) are mostly characterized by low computing power, limited batteries, low memory, low power consumption and low operating frequency range [1, 11, 2, 24, 25]. These devices are often employed in poorly accessible and sometimes critical environments (e.g. in military applications) and work with limited batteries and an insecure communication channel, and all these factors highlight their need to robust cryptographic solutions [4, 5, 11, 24, 25]. On the other hand, the high computation and energy requirements of common cryptography methods such as AES, RSA emphasize the focus on lightweight solutions. So the growing use and development of resource-constrained devices such as smart phones, smart cards, etc. and the rising importance of security as their core principle has led to increased interest to lightweight cryptography [1, 2, 5, 25]. The lightweight symmetric ciphers can be categorized into two classes: Block-based and stream- based. The following is a brief introduction to some of the lightweight block ciphers available in the literature. SEA: This cipher was designed in 2006 by Standaert et al. The design of this cipher is based on low memory requirements, minimal code size, and limited instruction set, plus flexibility, which is an unusual design criterion for ciphers. This cipher is based on Feistel structure and it can work with different text, key, and word sizes. This cipher is denoted by SEAn,b , where n is the plaintext size and key size, and b is the processor (or word) size. Due to its simplicity constraints, this cipher employs a limited number of basic operations, such as bitwise XOR, substitution box S, word (left) rotation, inverse word rotation, bit rotation, and modular addition [27]. HIGHT: This cipher was developed by Deukjo Hong et al. in 2006. It uses a 64-bit block size and a 128-bit key size. Its basic structure is 32-round type-2 generalized Feistel Network (GFN-2). The encryption processing of this cipher starts with initial conversion of the block, continues with a 32-round iterative function, and ends with final transform of the output of round function. The mentioned round function employs two functions F0 and F1 plus XOR and addition operations. Functions F0 and F1 are based on simple XOR and shift operations [20]. Hummingbird: This cipher was introduced in 2010 by Daniel Engels et al. It has a hybrid structure composed of block- and stream-based designs. It employs a 16-bit block size, a 256-bit key size and an 80-bit internal state. The size of the key and the internal state of Hummingbird provides an adequate level of security for many embedded applications. The overall structure of the Hummingbird encryption algorithm uses four 16-bit block ciphers Ek1,Ek2,Ek3,Ek4, plus 16-bit internal state registers,

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