Biblio

In smart city construction, wireless sensor networks (WSNs) are normally deployed to collect and transmit real-time data. The nodes of the WSN are embedded facility that integrated sensors and data processing modules. For security and privacy concerns, cryptography methods are required for data protection. However, the Rivest-Shamir-Adleman (RSA) cryptosystem, known as the the most popular and deployed public key algorithm, is still hardly implemented on embedded devices because of the intense computation required from its inherent arithmetic operations. Even though, different methods have being proposed for more efficient RSA implementations such as utilizing the Chinese remainder theorem, various modular exponentiation methods, and optimized modular arithmetic methods. In this paper, we propose an efficient multiplication for long integers on the sensor nodes equipped with 16-bit microcontrollers. Combined with this efficient multiplication, we obtain a faster Montgomery multiplication. The combined optimized Montgomery multiplication, the Chinese remainder theorem, and the m-ary exponentiation method allowed for execution times of less than 44.6 × 106 clock cycles for RSA decryption, a new speed record for the RSA implementation on MSP430 microcontrollers.

Over recent years lattice-based cryptography has received much attention due to versatile average-case problems like Ring-LWE or Ring-SIS that appear to be intractable by quantum computers. In this work, we evaluate and compare implementations of Ring-LWE encryption and the bimodal lattice signature scheme (BLISS) on an 8-bit Atmel ATxmega128 microcontroller. Our implementation of Ring-LWE encryption provides comprehensive protection against timing side-channels and takes 24.9ms for encryption and 6.7ms for decryption. To compute a BLISS signature, our software takes 317ms and 86ms for verification. These results underline the feasibility of lattice-based cryptography on constrained devices.