Design, Implementation and Validation of NSCP: A New Secure Channel Protocol for Hardened IoT

This paper deals with the design, implementation and validation of a new secure channel protocol to connect microcontrollers and secure elements. The new secure channel protocol (NSCP) relies on a lightweight cryptographic primitive (Xoodyak) and simplified operating principles to provide secure data exchange. The performance of the new protocol is compared with that of GlobalPlatform's Secure Channel Protocol 03 (SCP03), the current de facto standard for hardening the connection between a microcontroller and a secure element in industrial IoT. The evaluation was performed in two scenarios where the secure element was emulated with an ARM Cortex M4 and an OpenHW RISC-V MPU synthesized on an Artix FPGA. The results of the evaluation are an indicator of the potential advantage of the new protocol over SCP03: In the best case, the new protocol is able to apply cryptographic protection to messages from 3.64x to 4x with respect to SCP03 at its maximum security level. The speedup in the channel initiation process is also considerable, with a factor of up to 3.7. These findings demonstrate that it is possible to conceive a new protocol which offers adequate cryptographic protection, while being more lightweight than the present standard.