Owens, Daniel

As the cryptographic community turns its focus toward post-quantum cryptography, the demand for classical cryptographic schemes such as Elliptic Curve Cryptography (ECC) remains high. ECC is mature, well studied, and used in a wide range of applications such as securing visits to web pages through a web browser, Bitcoin, and the Internet of Things (IoT). In this work we present an optimized implementation of the Edwards Curve Digital Signature Algorithm (EdDSA) operations Key Generation and Sign using the Ed25519 parameter on the ARM Cortex-M4, and we discuss the optimization of field and group arithmetic to produce high throughput cryptographic primitives. In addition, we discuss several techniques for optimizing scalar multiplication, and present timing and memory consumption for each, as well as comparisons to other works. Our fastest implementation performs an Ed25519 Key Generation operation in 250,785 cycles and signing in 435,426 cycles utilizing 6.1 kB of additional Read Only Memory (ROM) space.