rust-sphinxcrypto

This crate provides a concrete parameterization of the Sphinx cryptographic packet format and follows this "Sphinx Mix Network Cryptographic Packet Format Specification" document:

https://github.com/katzenpost/docs/blob/master/specs/sphinx.rst

Sphinx has the following features:

• Single Use Reply Blocks
• per hop bitwise unlinkability
• indistinguishable replies
• hidden the path length
• hidden the relay position
• tagging attack detection
• reply attack detection

Read the Sphinx paper, Sphinx: A Compact and Provably Secure Mix Format by George Danezis and Ian Goldberg. See https://cypherpunks.ca/~iang/pubs/Sphinx_Oakland09.pdf

warning

This code has not been formally audited by a cryptographer. It therefore should not be considered safe or correct. Use it at your own risk!

details

The currently implemented Sphinx cryptographic parameterization is:

• EXP(X, Y) - X25519
• MAC(K, M), H(M) - Blake2b
• S(K, IV) - Chacha20
• KDF(SALT, IKM) - HKDF Sha256
• SPRPEncrypt(K, M)/SPRPDecrypt(K, M) - AEZ

The Sphinx packet geometry is parameterized in the constants submodule.

Usage

To import sphinxcrypto, add the following to the dependencies section of your project's Cargo.toml: toml sphinxcrypto = "^0.0.13" Then import the crate as: rust,no_run extern crate sphinxcrypto;

acknowledgments

This library is a Rust language port of Yawning's Katzenpost Sphinx implementation:

https://github.com/katzenpost/core/tree/master/sphinx

Thanks to Jeff Burdges for helping me with some of my rust problems.

license

GNU AFFERO GENERAL PUBLIC LICENSE