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Cryptographic Primitives

The Ika SDK supports a variety of cryptographic primitives for creating and managing dWallets. This guide provides a comprehensive reference for supported curves, signature algorithms, and hash schemes, along with their valid combinations.

Overview​

The SDK provides three main categories of cryptographic primitives:

  • Curves: The elliptic curves used for key generation
  • Signature Algorithms: The cryptographic signature schemes
  • Hash Schemes: The hashing algorithms used before signing

Not all combinations are valid. Each signature algorithm is tied to a specific curve and supports specific hash schemes.

Supported Curves​

The Ika SDK supports four elliptic curves:

Curve.SECP256K1​

The secp256k1 curve, widely used in blockchain applications.

  • Used by: Bitcoin, Ethereum
  • Signature Algorithms: ECDSASecp256k1, Taproot
  • Key Size: 256 bits
import { Curve } from '@dwallet-network/dwallet.js';

const curve = Curve.SECP256K1;

Curve.SECP256R1​

The secp256r1 curve (also known as P-256 or prime256v1), standardized by NIST.

  • Used by: WebAuthn, Apple Secure Enclave, many enterprise systems
  • Signature Algorithms: ECDSASecp256r1
  • Key Size: 256 bits
const curve = Curve.SECP256R1;

Curve.ED25519​

The Ed25519 curve, designed for high performance and security.

  • Used by: Solana, many modern cryptographic systems
  • Signature Algorithms: EdDSA
  • Key Size: 256 bits
const curve = Curve.ED25519;

Curve.RISTRETTO​

The Ristretto group, built on top of Curve25519 to provide a prime-order group.

  • Used by: Polkadot, Substrate-based chains
  • Signature Algorithms: SchnorrkelSubstrate
  • Key Size: 256 bits
const curve = Curve.RISTRETTO;

Supported Signature Algorithms​

The SDK supports five signature algorithms:

SignatureAlgorithm.ECDSASecp256k1​

Elliptic Curve Digital Signature Algorithm using the secp256k1 curve.

  • Curve: Curve.SECP256K1
  • Supported Hashes: KECCAK256, SHA256, DoubleSHA256
  • Use Cases: Bitcoin transactions, Ethereum transactions
import { Hash, SignatureAlgorithm } from '@dwallet-network/dwallet.js';

const signatureAlgorithm = SignatureAlgorithm.ECDSASecp256k1;
const hash = Hash.KECCAK256; // or Hash.SHA256, Hash.DoubleSHA256

SignatureAlgorithm.Taproot​

Schnorr signatures as specified in Bitcoin's Taproot upgrade (BIP-340/341/342).

  • Curve: Curve.SECP256K1
  • Supported Hashes: SHA256 only
  • Use Cases: Bitcoin Taproot transactions
const signatureAlgorithm = SignatureAlgorithm.Taproot;
const hash = Hash.SHA256; // SHA256 is the only valid hash for Taproot

SignatureAlgorithm.ECDSASecp256r1​

Elliptic Curve Digital Signature Algorithm using the secp256r1 (P-256) curve.

  • Curve: Curve.SECP256R1
  • Supported Hashes: SHA256
  • Use Cases: WebAuthn, enterprise applications, Apple devices
const signatureAlgorithm = SignatureAlgorithm.ECDSASecp256r1;
const hash = Hash.SHA256; // SHA256 is the only valid hash for ECDSASecp256r1

SignatureAlgorithm.EdDSA​

Edwards-curve Digital Signature Algorithm using the Ed25519 curve.

  • Curve: Curve.ED25519
  • Supported Hashes: SHA512 only
  • Use Cases: Solana transactions, modern cryptographic systems
const signatureAlgorithm = SignatureAlgorithm.EdDSA;
const hash = Hash.SHA512; // SHA512 is the only valid hash for EdDSA

SignatureAlgorithm.SchnorrkelSubstrate​

Schnorr signatures using the Ristretto group, as implemented in Substrate.

  • Curve: Curve.RISTRETTO
  • Supported Hashes: Merlin only
  • Use Cases: Polkadot, Substrate-based blockchain transactions
const signatureAlgorithm = SignatureAlgorithm.SchnorrkelSubstrate;
const hash = Hash.Merlin; // Merlin is the only valid hash for SchnorrkelSubstrate

Supported Hash Schemes​

The SDK supports five hash schemes:

Hash.KECCAK256​

KECCAK-256, also known as SHA-3.

  • Compatible with: ECDSASecp256k1
  • Output Size: 256 bits
  • Primary Use: Ethereum transactions
const hash = Hash.KECCAK256;

Hash.SHA256​

SHA-256, part of the SHA-2 family.

  • Compatible with: ECDSASecp256k1, Taproot, ECDSASecp256r1
  • Output Size: 256 bits
  • Primary Use: Bitcoin transactions, general purpose signing
const hash = Hash.SHA256;

Hash.DoubleSHA256​

Double SHA-256: h(x) = SHA256(SHA256(x)).

  • Compatible with: ECDSASecp256k1
  • Output Size: 256 bits
  • Primary Use: Legacy Bitcoin transactions
const hash = Hash.DoubleSHA256;

Hash.SHA512​

SHA-512, part of the SHA-2 family.

  • Compatible with: EdDSA
  • Output Size: 512 bits
  • Primary Use: EdDSA signatures (Solana, etc.)
const hash = Hash.SHA512;

Hash.Merlin​

Merlin, a STROBE-based transcript construction protocol.

  • Compatible with: SchnorrkelSubstrate
  • Primary Use: Substrate-based chains (Polkadot, etc.)
const hash = Hash.Merlin;

Best Practices​

  1. Choose the Right Curve: Select the curve based on your target blockchain or application:

    • Use SECP256K1 for Bitcoin and Ethereum
    • Use SECP256R1 for WebAuthn and enterprise applications
    • Use ED25519 for Solana and high-performance applications
    • Use RISTRETTO for Polkadot and Substrate chains

  2. Use Appropriate Hash Schemes: Each blockchain expects signatures with specific hash schemes:

    • Ethereum requires KECCAK256
    • Bitcoin Legacy requires DoubleSHA256
    • Bitcoin Taproot requires SHA256
    • Most other applications use SHA256

  3. Validate Before Signing: Always ensure your combination of curve, signature algorithm, and hash scheme is valid before attempting to sign.

Additional Resources​

For more details on the cryptographic implementations, refer to:

  • BIP-340 - Schnorr Signatures for secp256k1 (Taproot)
  • RFC 8032 - Edwards-Curve Digital Signature Algorithm (EdDSA)
  • SEC 2 - Recommended Elliptic Curve Domain Parameters
  • Ristretto - The Ristretto Group