A novel 5-bit S-box design for lightweight cryptography algorithms
Vishal A. Thakor, Mohammad A. Razzaque, Anand D. Darji, Aksh Patel
Abstract
Cryptography is one of the techniques to secure communication and data transfer over the network. It performs well on resource-rich devices (PC, servers, smartphones, etc.). However, it may not fit or, if forcefully fitted, perform poorly on the resource-constrained Internet of Things (IoT) devices (e.g., Radio Frequency Identification (RFID) tags, sensors). For these reasons, there is a need for a lightweight version of cryptography, called lightweight cryptography (LWC). While designing any cryptography algorithm, a substitution box (S-box) is a core and the only component that offers a nonlinear functionality between inputs and outputs. Various researchers propose various S-box designs for different applications. Still, very few of them maintain the trade-offs among cost, performance and security, especially when considered resource-constrained IoT devices. First, the article discusses various S-boxes used in the popular LWC algorithms by their input–output bit-size (3/4/5/6/8 bit) and highlights their strengths and limitations. Then, it focuses on the proposed 5-bit S-box design. The novel design uses a chaotic mapping theory to offer a random behaviour of the element in the proposed S-box. The experimental results from ASIC implementation reveal two essential characteristics of the proposed S-box, cost and performance, and further, compare it with 4/5-bit S-box competitors. Finally, the article demonstrates the security strength of the proposed 5-bit S-box through various cryptanalysis such as bijective, nonlinearity, linearity, differential cryptanalysis, differential style boomerang attack, avalanche effect, bit independence criterion, etc. Also, a comparison is carried out to exhibit the superiority of the proposed 5-bit S-box over its 5-bit competitors.