salty

Overview

Small, sweet, swift: Ed25519 signatures for microcontrollers.
With assembly optimizations for Cortex-M4 and Cortex-M33.

NOTE: This is work-in-progress and not audited! The usual warnings apply: Your hamster will explode, etc. etc.

Work on salty is sponsored by

Goals

From highest to lowest priority:

• understandable code
• timing side-channel free
• design for easy integration in embedded projects
• sufficiently small compiled code size
• useful speed

The Plan

None of these releases exist quite yet.

v0.1.0

Basic signature functionality

• allocation free API for signatures
• transcription of Ed25519 from TweetNaCl
• Bjoern Haase's field arithmetic optimizations
• use subtle

v0.2.0

More tests!

• fuzzing to test correctness against known good implementation
• side-fuzzing to test for timing side-channels

v0.3.0

Completion! The rest of NaCl.

• X22519
• authenticated encryption

License

^{The scalar29 implementation is from curve25519-daleks's u32 backend: LICENSE.
Salty is licensed under either of Apache License, Version 2.0 or MIT License at your option.}
_{Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.
TweetNaCl is a public-domain library.
fe25519 is licensed under Creative Commons Zero v1.0 Universal.}