CIRCL

CIRCL (Cloudflare Interoperable, Reusable Cryptographic Library) is a collection of cryptographic primitives written in Go. The goal of this library is to be used as a tool for experimental deployment of cryptographic algorithms targeting Post-Quantum (PQ) and Elliptic Curve Cryptography (ECC).

Security Disclaimer

🚨 This library is offered as-is, and without a guarantee. Therefore, it is expected that changes in the code, repository, and API occur in the future. We recommend to take caution before using this library in a production application since part of its content is experimental. All security issues must be reported, please notify us immediately following the instructions given in our Security Policy.

Installation

You can get CIRCL by fetching:

go get -u github.com/cloudflare/circl

List of Algorithms

Diffie-Hellman Protocol

• X25519
• X448
• Curve4Q

Digital Signature Schemes

• Ed25519
• Ed448

Groups based on Elliptic Curves

• P-256, P-384, P-521, FIPS 186-4
• Ristretto
• Hash to Curve

High-Level Protocols

• HPKE: Hybrid Public-Key Encryption
• VOPRF: Verifiable Oblivious Pseudorandom function: OPRF, VOPRF and POPRF modes.
• BlindRSA: Blind RSA signatures.
• CPABE: Ciphertext-policy Attribute-based Encryption.

Post-Quantum Key Encapsulation Methods

• CSIDH: Post-Quantum Commutative Group Action
• Kyber KEM: modes 512, 768, 1024
• FrodoKEM KEM: modes 640-SHAKE
• (insecure, deprecated) SIDH/SIKE: Supersingular Key Encapsulation with primes p434, p503, p751

Post-Quantum Public-Key Encryption

• Kyber PKE: modes 512, 768, 1024

Post-Quantum Digital Signature Schemes

• Dilithium: modes 2, 3, 5

Field Arithmetic

• Fp25519, Fp448, Fp381

Elliptic Curves

• P-384 Curve
• FourQ
• Goldilocks
• BLS12-381: Bilinear pairings, hash to G1 and G2.

Parallel SIMD

• Keccak f1600 Permutation

XOF: eXtendable Output Functions

• FIPS 202: SHAKE128 and SHAKE256
• BLAKE2X: BLAKE2XB and BLAKE2XS
• KangarooTwelve: KangarooTwelve

Zero-knowledge Proofs

• Schnorr: Prove knowledge of the Discrete Logarithm.
• DLEQ: Prove knowledge of the Discrete Logarithm Equality.

Testing and Benchmarking

Library comes with number of make targets which can be used for testing and benchmarking:

• test performs testing of the binary.
• bench runs benchmarks.
• cover produces coverage.
• lint runs set of linters on the code base.

Contributing

To contribute, fork this repository and make your changes, and then make a Pull Request. A Pull Request requires approval of the admin team and a successful CI build.

How to Cite

To cite CIRCL, use one of the following formats and update the version and date you accessed this project.

APA Style

Faz-Hernández, A. and Kwiatkowski, K. (2019). Introducing CIRCL:
An Advanced Cryptographic Library. Cloudflare. Available at
https://github.com/cloudflare/circl. v1.3.3 Accessed May, 2023.

Bibtex Source

@manual{circl,
  title        = {Introducing CIRCL: An Advanced Cryptographic Library},
  author       = {Armando Faz-Hern\'{a}ndez and Kris Kwiatkowski},
  organization = {Cloudflare},
  abstract     = {{CIRCL (Cloudflare Interoperable, Reusable Cryptographic Library) is
                   a collection of cryptographic primitives written in Go. The goal
                   of this library is to be used as a tool for experimental
                   deployment of cryptographic algorithms targeting Post-Quantum (PQ)
                   and Elliptic Curve Cryptography (ECC).}},
  note         = {Available at \url{https://github.com/cloudflare/circl}. v1.3.3 Accessed May, 2023},
  month        = jun,
  year         = {2019}
}

CFF Style

See attached CITATION.cff file.

License

The project is licensed under the BSD-3-Clause License.