The Sony Corporation recently announced that CLEFIA, the block cipher algorithm it developed and presented as a state-of-the-art cryptography technique in 2007, has been adopted as one of the ISO/IEC 29192 International Standards in lightweight cryptography after the final approval of ISO (International Organization for Standardization)/IEC (International Electrotechnical Commission).
CLEFIA, which has the same interface as the US government’s Advanced Encryption Standard (AES), met the requirements of ISO/IEC 29192, as prescribed by the ISO/IEC JTC 1/SC 27 – the organization responsible for determining the International Standards for information security.
The CLEFIA block cipher has a block length of 128 bits, while key length can be selected from 128 bits, 192 bits or 256 bits. The most impressive feature of CLEFIA is its realization of implementation efficiency while maintaining a high level of security.
The development of CLEFIA maintains superior security based on the latest block cipher design theory. Furthermore, it adopts the general Feistel structure, which is suited for implementation in constrained environments. Also, the Diffusion Switching Mechanism (DSM) is employed to reduce processing operations while ensuring security. In addition, components for data processing and key scheduling part are shared. These improvements have made it possible to achieve efficient implementations in hardware and software, which had been difficult with conventional encryption technologies.
This excellent implementation efficiency enables CLEFIA to demonstrate high performance in devices with limited resources or those with low-power consumption requirements. Accordingly, CLEFIA is suited for lightweight cryptographic applications as indicated in ISO/IEC 29192 in smartcards, RFID tags, sensor networks, medical devices and more, in addition to conventional applications.