Multi-core data analytics SoC with a flexible 1.76 Gbit/s AES-XTS cryptographic accelerator in 65 nm CMOS

Abstract

Embedded systems for Internet-of-Things applications present new challenges to system design. From a hardware design perspective, energy efficiency is paramount, as most of devices have a limited power supply due to size considerations. Transmitting data away from the node remains a very power hungry operation, and the only viable solution to this problem is to reduce the amount of data by performing pre-processing which again requires additional computational power. Hence modern embedded devices need to strike a fine balance between the power needed for acquisition/processing and communication. In many scenarios, small IoT devices will be deployed widely making them vulnerable to malicious attacks. Thus, for practical applications, these devices also need to fit the necessary resources to provide adequate security services. We present a cryptographic hardware accelerator capable of supporting multiple encryption and decryption modes for different cryptographic algorithms (AES, Keccak) in an energy efficient multi-core cluster optimized for embedded digital signal processing applications implemented in 65 nm CMOS technology. We show that it is possible to have the necessary computation power to perform cryptographic services in addition to state of the art processing in a power budget that is compatible with IoT devices in a mature 65 nm CMOS technology. When running at 0.8 V the SoC with the cryptographic accelerator can be clocked at 84 MHz running AES-XTS at more than 250 Mbits/s consuming a total of 27 mW, which is a 100 × gain in energy and 496 × gain in operation speed over an optimized software implementation running on a single 32 bit OpenRISC core.