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Module eddsa

dcrypt_sign

Module eddsa 

Source
Expand description

EdDSA (Edwards-curve Digital Signature Algorithm) implementations

This module provides a dcrypt-owned, safe-Rust Ed25519 implementation with strict canonical and prime-subgroup validation. This description is not an independent audit or production-safety claim.

§Security Features

  • Immutable secret keys: Prevents accidental key corruption
  • Automatic zeroization: Clears sensitive data from memory
  • Secure API design: Minimal surface area, maximum safety
  • Fixed-schedule secret arithmetic: Secret scalar multiplication uses constant-time selection rather than secret-dependent branches
  • Type safety: Strong typing prevents key confusion

§Features

  • RFC 8032 Ed25519 signing and strict verification
  • Deterministic signature generation
  • Secure key generation and handling
  • Comprehensive input validation
  • Key derivation and persistence support

§Security Guidelines

  1. Supply a CSPRNG: Key generation uses only the caller-provided RNG; this crate does not obtain entropy from the operating system
  2. Protect seeds: Encrypt before storage, decrypt only when needed
  3. Verify public keys: Confirm authenticity through secure channels
  4. Clear sensitive data: Automatic for secret keys, manual for seeds

§Example

use dcrypt_sign::eddsa::{Ed25519, Ed25519SecretKey};
use dcrypt_api::Signature;

// Load a seed supplied by the application's key-management boundary.
let seed = [42u8; 32];
let secret_key = Ed25519SecretKey::from_seed(&seed)?;
let public_key = secret_key.public_key()?;

// Sign a message
let message = b"Hello, Ed25519!";
let signature = Ed25519::sign(message, &secret_key)?;

// Verify the signature
assert!(Ed25519::verify(message, &signature, &public_key).is_ok());

// Save the secret key seed (encrypt in production!)
let seed = secret_key.seed();

// Later, reconstruct the secret key
let reconstructed_secret = Ed25519SecretKey::from_seed(seed)?;
let reconstructed_public = reconstructed_secret.public_key()?;

// The reconstructed keys work identically
assert_eq!(public_key.0, reconstructed_public.0);

Structs§

Ed25519
Ed25519 signature scheme.
Ed25519PublicKey
Canonically encoded, non-identity, prime-order Ed25519 public key.
Ed25519SecretKey
Ed25519 secret seed, wiped on drop.
Ed25519Signature
Canonically encoded Ed25519 signature bytes (R || S).