This repository contains optimized assembly implementations of various cryptographic primitives. They are part of a research paper with the title 'Efficient Cryptography on the RISC-V Architecture'.

• aes128tables contains a table-based AES-128 implementation. This should only be used if you are aware of the risks of cache-based timing attacks and you can guarantee that this is of no concern for your specific use case.
• aes128ctrbs contains a bitsliced AES-128-CTR implementation.
• chacha20 contains an implementation of the ChaCha20 stream cipher.
• keccakf1600 contains an implementation of the Keccak-f[1600] permutation.

This code uses SiFive's Freedom E SDK that is included as git submodule. That SDK requires that you have the RISC-V GNU toolchain and RISCV OpenOCD. For the GNU toolchain, make sure that multilib is enabled such that you can cross-compile for 32-bit targets. Then put both tools in you $PATH or edit the Makefile and add their locations to BIN_DIR. Once that is done, simply calling make should be sufficient to build 4 binaries in their respective directories. These binaries target the HiFive1 development board.

Connect the HiFive1 over USB. In one terminal, execute ./watch.sh on Linux. This will execute screen on /dev/ttyUSB1. In another terminal, execute ./upload.sh <dir/binary.elf>. This uses riscv64-unknown-elf-gdb and openocd to flash the binary to the HiFive1 board.