K1 ?

Safer than K2

K1 is Swift wrapper around libsecp256k1 (bitcoin-core/secp256k1), offering ECDSA, Schnorr and ECDH features.

Features

ECDSA Signatures

let alice = try K1.PrivateKey.generateNew()
let message = "Send Bob 3 BTC".data(using: .utf8)!
let signature = try alice.ecdsaSign(unhashed: message)
let isSignatureValid = try alice.publicKey.isValidECDSASignature(signature, unhashed: message)
assert(isSignatureValid, "Signature should be valid.")

Schnorr Signatures

let alice = try K1.PrivateKey.generateNew()
let message = "Send Bob 3 BTC".data(using: .utf8)!
let signature = try alice.schnorrSign(unhashed: message)
let isSignatureValid = try alice.publicKey.isValidSchnorrSignature(signature, unhashed: message)
assert(isSignatureValid, "Signature should be valid.")

ECDH

let alice = try K1.PrivateKey.generateNew()
let bob = try K1.PrivateKey.generateNew()

let ab = try alice.sharedSecret(with: bob.publicKey)
let ba = try bob.sharedSecret(with: alice.publicKey)
assert(ab == ba, "Alice and Bob should be able to agree on the same secret")

Alternatives

GigaBitcoin/secp256k1.swift (also using libsecp256k1, ❌ No Schnorr)
KevinVitale/WalletKit (also using libsecp256k1, ❌ No Schnorr)
yenom/BitcoinKit (? Discontinued, also using libsecp256k1, ❌ No Schnorr)
oleganza/CoreBitcoin (ObjC + Swift, ❌ No Schnorr)
Sajjon/EllipticCurveKit (mine, ☣️ unsafe, ✅ Schnorr support)

Non-Swift but SPM support

greymass/secp256k1 (Fork of libsecp256k1)

GitHub

View Github