Towards the world's fastest Beyond 5G/6G: Ultra-high-speed encryption algorithm "Rocca" developed by KDDI Research, Inc. and the University of Hyogo

A research group composed of KDDI Research, Inc. and Associate Professor Takanori Isobe of the University of Hyogo Graduate School of Information Science developed a new common key encryption algorithm called "Rocca," which has the processing performance and security required in the Beyond 5G/6G era. This is an AEAD that supports a key length of 256 bits, and achieves the world's fastest processing speed of 138 Gbps. The results were recorded at the 28^th annual Fast Software Encryption conference (FSE2022), a premier international conference on encryption software implementation, and will be announced in March 2022.

Beyond 5G/6G, which is currently attracting attention worldwide, is undergoing research and development, with the goal of reaching communication speeds exceeding 100 Gbps. Services that require ultra-high-speed communication, such as large-capacity video transmission, require encryption algorithms with a similar processing performance. The following three requirements are required for common key encryption in the Beyond 5G/6G era: (1) a processing speed of over 100 Gbps, which avoids a bottleneck in communication, (2) support of a 256-bit key length to make it resistant to decryption by quantum computers, and (3) integration of encryption and authentication functions to create an algorithm (authenticated encryption) that can guarantee that the data has not been tampered with. Developed by the research group, "Rocca" is an encryption algorithm that meets these requirements.

"Rocca" has the main components of operations (including AES-NI), which can be processed at high-speed using the CPU of a PC or smartphone, and it realizes high speed by efficiently processing them in parallel. In addition, by arranging this in a structure that can ensure sufficient safety, both high speed and safety are achieved. When a speed comparison of AES, which is a common key encryption system widely used as the US standard, was performed, AES achieved a speed of at least 100 times more than when AES-NI (an instruction set that executes AES processing at high speed) was not used, and it was approximately 4.5-times faster even when AES-NI was used. In addition, as an authenticated encryption algorithm that supports a 256-bit key length, the system achieved a processing performance of 138 Gbps, exceeding 100 Gbps for the first time. This is the fastest measurement result of authenticated encryption corresponding to a software-implemented 256-bit key length.

In the future, the research group will work on further speeding up the algorithm and carry out detailed safety evaluations in collaboration with external organizations. For future practical use, the group will also work on a performance evaluation in an environment for practical applications, such as on smartphones.