Cryptographic Primitives

pub struct TransactionSigner {
    signing_key: SigningKey,  // Ed25519 private key
}

pub struct SignatureVerifier;  // Stateless verifier

impl SignatureVerifier {
    /// Verify Ed25519 signature with strict validation
    pub fn verify_strict(public_key: &[u8], message: &[u8], signature: &[u8]) -> CryptoResult<bool> {
        // Uses verify_strict() to prevent weak public key forgery attacks
        let verifying_key = VerifyingKey::from_bytes(public_key)?;
        let signature = Signature::from_bytes(signature)?;

        match verifying_key.verify_strict(message, &signature) {
            Ok(()) => Ok(true),
            Err(_) => Ok(false),
        }
    }
}