A Simple and Efficient Way to Combine Microcontrollers with RSA Cryptography

Microcontroller can be easily adopted in various applications with a variety of peripherals due to its merits of small size, simple architecture and etc. However, the limited computing power restricts its application in cryptography. In this paper, we try to integrate microcontroller with different peripheral devices to support more powerful cryptography computation in a simple and efficient way. Based on the most popular open source microcontroller development platform, Arduino, we design and develop a cryptographic hardware device for a real-life application which provides data protection functions for authority and integrity with RSA cryptography supported. With the peripherals Java card, our Arduino-cored solution is able to efficiently generate digital signature of photos taken by smart phone using the asymmetric cryptographic algorithm, RSA, which has a poor performance if it is directly implemented on microcontroller. The experimental results show that the device can finish a RSA 1024-bit encryption in 82.2 microseconds, which is reasonable in real application scenario and illustrates the feasibility of implementing more complicated cryptographic system using microcontroller.