Skip to main content

Specifications & Standards

DotRing implements multiple cryptographic specifications and standards.

Implemented Standards​

RFC 9381 - ECVRF​

Verifiable Random Functions using Elliptic Curves

  • Status: Proposed Standard
  • Link: RFC 9381
  • Implementation: IETF_VRF class

Key features:

  • Elliptic curve VRF construction
  • Schnorr-style proofs
  • Hash-to-curve integration

RFC 9380 - Hash to Curve​

Hashing to Elliptic Curves

  • Status: Proposed Standard
  • Link: RFC 9380
  • Implementation: All curves support compliant hash-to-curve

Supported methods:

  • _RO - Random Oracle (default)
  • _NU - Non-Uniform

Bandersnatch VRF Specification​

Pedersen VRF on Bandersnatch Curve

Key features:

  • Pedersen commitment-based key blinding
  • Unlinkable proofs
  • Deterministic blinding derivation

Ring Proof Specification​

Ring VRF with KZG Commitments

Key features:

  • Constant-size ring proofs
  • KZG polynomial commitments
  • Plonk constraint system

Test Vectors​

DotRing includes test vectors from:

IETF Test Vectors​

Located in tests/vectors/:

tests/vectors/
├── ietf/
│   ├── bandersnatch.json
│   ├── ed25519.json
│   └── secp256k1.json

ark-vrf Compatibility​

Test vectors compatible with ark-vrf Rust implementation:

# Cross-validate with ark-vrf
from dot_ring import Bandersnatch, IETF_VRF

# Test vector from ark-vrf
sk = bytes.fromhex("...")
alpha = bytes.fromhex("...")
expected_proof = bytes.fromhex("...")

proof = IETF_VRF[Bandersnatch].prove(alpha, sk, b'')
assert proof.to_bytes() == expected_proof

Curve Specifications​

Bandersnatch​

  • Type: Twisted Edwards
  • Defined over: BLS12-381 scalar field
  • Prime Field: p = 0x73eda753...00000001 (BLS12-381 scalar field)
  • Order: q = 0x1cfb69d4...876e7e1
  • Cofactor: 4
  • Edwards a: -5
  • Spec: Bandersnatch (MSZ21)

Ed25519​

  • Type: Twisted Edwards
  • RFC: RFC 8032
  • Field: Fp\mathbb{F}_p where p=2255−19p = 2^{255} - 19
  • Order: q≈2252q \approx 2^{252}

secp256k1​

  • Type: Short Weierstrass
  • Spec: SEC 2
  • Field: 256-bit prime field
  • Used by: Bitcoin, Ethereum

BLS12-381​

  • Type: Pairing-friendly
  • Spec: BLS12-381
  • Groups: G1 (48 bytes), G2 (96 bytes)
  • Used for: KZG commitments, BLS signatures

Cryptographic Primitives​

Hash Functions​

UsageAlgorithm
VRF ChallengeSHA-512
Output HashSHA-256
Fiat-ShamirKeccak256
Hash-to-CurveSHA-256/SHA-512

Pairing Operations​

Ring VRF uses BLS12-381 pairings via blst:

# blst provides:
# - Fast pairing computation
# - G1/G2 point operations
# - Scalar multiplication

Compliance Testing​

Run Specification Tests​

# IETF VRF tests
pytest tests/test_ietf/ -v

# Pedersen VRF tests
pytest tests/test_pedersen/ -v

# Ring VRF tests
pytest tests/test_ring_vrf/ -v

# Hash-to-curve tests
pytest tests/test_h2c_suites/ -v

Cross-Implementation Testing​

DotRing proofs are compatible with:

ImplementationLanguageCompatibility
ark-vrfRust✅ Full
w3f-ring-proofRust✅ Full

Security Considerations​

Trusted Setup​

Ring VRF uses powers of tau from:

  • Ceremony: Zcash Powers of Tau
  • Participants: 1000+
  • Security: Secure if ≥1 honest participant

Constant-Time Operations​

All secret-dependent operations use constant-time implementations to prevent timing attacks.

Random Number Generation​

Secret keys should be generated using cryptographically secure RNG:

import secrets
secret_key = secrets.token_bytes(32)  # ✅ Secure

import random
secret_key = random.randbytes(32)  # ❌ NOT secure for crypto

Version Compatibility​

DotRing VersionPythonark-vrfw3f-ring-proof
0.1.x3.12+0.5.x0.1.x

References​

Papers​

  1. VRF: Micali, Rabin, Vadhan (1999) - "Verifiable Random Functions"
  2. Pedersen: Pedersen (1992) - "Non-Interactive and Information-Theoretic Secure Verifiable Secret Sharing"
  3. KZG: Kate, Zaverucha, Goldberg (2010) - "Constant-Size Commitments to Polynomials"
  4. Plonk: Gabizon et al. (2019) - "PLONK: Permutations over Lagrange-bases"
  5. Ring VRF: BCGSV23 - Ring VRF paper

Implementations​