ore.rs

(pronounced "auras")

This is an Order Revealing Encryption (ORE) library written in Rust and based on the Block-ORE Encryption scheme developed by Lewi-Wu in 2016.

It makes the following improvements on the original scheme:

• Use of a Knuth (Fisher-Yates) Shuffle for the PRP (instead of a Feistel Network which was found to be insecure for small domains (see Bogatov et al)
• Exclusive use of AES as a Random Oracle
• Pipeline optimisations, for higher throughput
• Both SIMD and Neon intrinsic support for x86_64 and ARM
• Inclusion of the block number in block prefixes, to avoid repeated prefixes

Usage Documentation

Reference documentation is on docs.rs/ore-rs.

Build, Test and Bench

To build, run:

cargo build

To test, run:

cargo test

To run the benchmarks, run:

cargo bench

Example benchmark results below:

ARMv8 and M1 Support

ARMv8 and M1 Macs work out of the box but will default to AES in software which is around 4x slower than AES-NI (at least on the test machine using an Intel i7 8700K).

To take advantage of hardware AES using NEON Intrinsics on ARM, you need to use Rust nightly.

asdf install rust nightly asdf local rust nightly cargo +nightly bench

TODO

• Constant time analysis to ensure that encryption or comparison time does not vary with input size
• Zeroing and careful cleaning up of memory where appropriate
• Support longer AES keys for the PRF and hash (if possible)
• Get rid of GenericArray and replace with const generics (blocked by support in the AES crate)