tlock: Practical Timelock Encryption/Decryption in Rust

tlock is a library to encrypt and decrypt 16-byte binaries using tlock scheme. It provides encrypt and decrypt methods consuming Threshold BLS signatures provided by drand beacons.

The reference interroperable Go implementation is available at drand/tlock.

Tables of Content

• Features
• Installation
• Usage
• Security Considerations
• FAQ
• License

Features

• Timelock encryption and decryption of 16-byte u8 array
• Encryption with public key on G1 and G2
• Interroperability with Go and JS implementation
• wasm32 compatible library

Installation

The library is tested against the following targets: x86_64-unknown-linux-gnu, armv7-unknown-linux-gnueabihf, aarch64-unknown-linux-gnu, wasm32-wasi.

Usage

Code examples are provided in tlock/examples.

The tlock system relies on unchained drand networks.

This crate does not provide a drand client. You can use drand_core.

Security Considerations

This software has not been audited. Please use at your sole discretion. With this in mind, dee security relies on the following:

• tlock: Practical Timelock Encryption from Threshold BLS by Nicolas Gailly, Kelsey Melissaris, and Yolan Romailler, and its implementation in drand/tlock,
• Identity-Based Encryption by Dan Boneh, and Matthew Franklin, and its implementation in thibmeu/tlock-rs,
• The choosen drand beacon to remain honest,

FAQ

I want to encrypt more than 16 bytes

You should consider using tlock_age. It relies on this library to encrypt an age filekey, allowing for file of arbitrary size to use timelock-encryption.

How does practical timelock encryption work

For the simple explanation, you can use Handwaving Cryptography.

For a more detailed one, you should take time to read tlock: Practical Timelock Encryption from Threshold BLS by Nicolas Gailly, Kelsey Melissaris, and Yolan Romailler.

RFC 9380 Hashing to Elliptic Curve

RFC 9380 standardises a lot of interactions with elliptic curves. tlock did not use it first, and has been upgraded to support it. The feature rfc9380 is enabled by default starting 0.0.4. This is not a backward compatible change.

License

This project is under the MIT license.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you shall be MIT licensed as above, without any additional terms or conditions.