ZKryptium

Description

Zkryptium library provides an experimental implementation for research purposes of:

• BBS+(draft-irtf-cfrg-bbs-signatures-12) signature scheme
• Blind BBS Signatures (draft-irtf-cfrg-bbs-blind-signatures-02) signature scheme with some fixes taken from grotto-bbs-signatures
• BBS per Verifier Linkability (draft-irtf-cfrg-bbs-per-verifier-linkability-03)
• CL2003 (https://link.springer.com/chapter/10.1007/3-540-36413-7_20) signature scheme

This library enables the creation of zero-knowledge proofs, exposing cryptographic primitives facilitating the development of a Verifiable Credentials (VCs) system capable of handling both Anonymous Credentials and Selective Disclosure Credentials.

WARNING: for CL2003 use a version from v0.3.2 onwards that uses a new secure cryptographic implementation of the Pseudo Random Number Generator ThreadRng

Getting Started

Requirements

• Rust (>= 1.65)
• Cargo (>= 1.65)
• The ZKryptium CL03 implementation also depends on the Rug crate which depends on GMP, MPFR and MPC libraries through the low-level FFI bindings in the gmp-mpfr-sys crate, which needs some setup to build; the gmp-mpfr-sys documentation has some details on usage under GNU/Linux, macOS and Windows.

Usage

BBS+:

[dependencies]
zkryptium = { version = "0.7.1", default-features = false, features = ["bbsplus"] }

BBS+ Blind signature:

[dependencies]
zkryptium = { version = "0.7.1", default-features = false, features = ["bbsplus", "bbsplus_blind"] }

BBS+ per Verifier Linkability:

[dependencies]
zkryptium = { version = "0.7.1", default-features = true}

CL2003:

[dependencies]
zkryptium = { version = "0.7.1", default-features = false, features = ["cl03"] }

Examples

Take a look at the examples.

You can run the examples based on the BBS+ Signature Scheme with:

cargo run --example bbsplus <ciphersuite>
cargo run --example bbsplus_blind <ciphersuite>
cargo run --example bbsplus_nym <ciphersuite>

Available Ciphersuites:

• BLS12-381-SHA-256
• BLS12-381-SHAKE-256

You can run the examples based on the CL2003 Signature Scheme with:

cargo run --features="cl03" --example cl03 <ciphersuite>
cargo run --features="cl03" --example cl03_multiattr <ciphersuite>

Available Ciphersuites:

• CL1024-SHA-256
• CL2048-SHA-256
• CL3072-SHA-256

Test

To test the library you can launch the test vectors with:

cargo test