Lightweight cryptography is an interesting fieldthat strikes the perfect balance in providing security, higher throughput, lowpower consumption, and compactness. In recent years, many compact algorithms like PRESENT, CLEFIA, SEA, TEA, LED, ZORRO, Hummingbird, and KANTAN have made the mark to be used as lightweight crypto engines. In this paper, we present the design of a new lightweight compact encryption system based on bit permutation instruction group operation (GRP), which is widely studied and extensively researched. Using the S-box of PRESENT, we have added the confusion property for GRP, because all the existing algorithms using bit permutation instructions do not have this confusion property. By comparing the existing S-boxes of compact algorithms and its cryptanalysis, a new hybrid system is proposed in this paper that provides more compact results in terms of both memory space and gate equivalents. A hybrid cryptosystem, which consists of GRP and S-box of PRESENT, is designed and implemented on a 32-bit processor. This fusion has resulted in a lightweight cipher that is the most compact implementation, till now, in terms of memory requirement. We have tested and verified this on an LPC2129 processor. Various S-boxes of recently used lightweight algorithms, such as PRESENT and CLEFIA, are designed and analyzed to create a perfect fusion that should be resistant to attacks. Using the S-box of PRESENT, it helps in further reducing the gate complexity. This hybrid model results in 2125 gate equivalents, which is better than other light variant models like DESXL, CLEFIA, and AES. Moreover, GRP properties are very helpful not only to attain the desired avalanche effect, but also as it results in a compact implementation in hardware. This paper proposes a novel approach that will have a positive impact in the field of lightweight encryption protocols.
Key words: Lightweight cryptography, PRESENT, GRP,embedded security, encryption, bit permutation