# ZKryptium

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[![](https://img.shields.io/crates/v/zkryptium?style=flat-square)](https://crates.io/crates/zkryptium)
[![](https://img.shields.io/docsrs/zkryptium?style=flat-square)](https://docs.rs/zkryptium/)

## Description

ZKryptium library provides an implementation of:
* **BBS+**([draft-irtf-cfrg-bbs-signatures-07](https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-bbs-signatures-07)) signature scheme
* **Blind BBS Signatures** ([draft-kalos-bbs-blind-signatures-01](https://datatracker.ietf.org/doc/html/draft-kalos-bbs-blind-signatures-01)) signature scheme
* **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](https://rust-random.github.io/rand/rand/rngs/struct.ThreadRng.html)

## Getting Started

### Requirements

- [Rust](https://www.rust-lang.org/) (>= 1.65)
- [Cargo](https://doc.rust-lang.org/cargo/) (>= 1.65)
- The ZKryptium **CL03** implementation also depends on the [Rug crate](https://crates.io/crates/rug) which depends on GMP, MPFR and MPC libraries through the low-level FFI bindings in the [gmp-mpfr-sys crate](https://crates.io/crates/gmp-mpfr-sys), which needs some setup to build; the [gmp-mpfr-sys documentation](https://docs.rs/gmp-mpfr-sys/1.6.1/gmp_mpfr_sys/index.html) has some details on usage under [GNU/Linux](https://docs.rs/gmp-mpfr-sys/1.6.1/gmp_mpfr_sys/index.html#building-on-gnulinux), [macOS](https://docs.rs/gmp-mpfr-sys/1.6.1/gmp_mpfr_sys/index.html#building-on-macos) and [Windows](https://docs.rs/gmp-mpfr-sys/1.6.1/gmp_mpfr_sys/index.html#building-on-windows).


### Usage

##### BBS+:

```toml
[dependencies]
zkryptium = { version = "0.3.2", default-features = false, features = ["bbsplus"] }
```

##### CL2003:

```toml
[dependencies]
zkryptium = { version = "0.3.2", default-features = false, features = ["cl03"] }
```

### Examples

Take a look at the [examples](https://github.com/Cybersecurity-LINKS/ZKryptium/tree/main/examples).

You can run the examples based on the [BBS+](https://identity.foundation/bbs-signature/draft-irtf-cfrg-bbs-signatures.html) Signature Scheme with:

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

##### Available Ciphersuites:
- BLS12-381-SHA-256
- BLS12-381-SHAKE-256

You can run the examples based on the [CL2003](https://link.springer.com/chapter/10.1007/3-540-36413-7_20) Signature Scheme with:
```
cargo run --features="cl03" --example cl03 <ciphersuite>
cargo run --features="cl03" --example cl03_multiattr <ciphersuite>
```
##### Available Ciphersuites:
- CL1024-SHA-256


## Test

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

```
cargo test
```

## Adopted by

We’re proud to be adopted by companies around the world. Here are a few of the organizations leveraging our library:
* [IOTA Foundation](https://github.com/iotaledger/identity.rs)
* [SpruceID](https://github.com/spruceid/ssi)
* [Hushmesh Inc.](https://github.com/hushmesh/mesh-infrastructure)