🔐 secp256k1.swift

Swift 包，包含椭圆曲线公钥密码学、ECDSA、Schnorr 签名，适用于比特币，并包含来自 libsecp256k1 的 C 绑定。

目标

长期目标是

轻量级 ECDSA 和 Schnorr 签名功能
构建用于简单或高级用法，例如 BIP340
暴露 C 绑定，以完全控制 secp256k1 的实现
通过模仿 Swift Crypto，采用熟悉的 API 设计
自动更新 Swift 和 libsecp256k1
可用于 Linux 和 Apple 平台生态系统

使用示例

ECDSA

import secp256k1

//  Private key
let privateBytes = try! "14E4A74438858920D8A35FB2D88677580B6A2EE9BE4E711AE34EC6B396D87B5C".bytes
let privateKey = try! secp256k1.Signing.PrivateKey(rawRepresentation: privateBytes)

//  Public key
print(String(bytes: privateKey.publicKey.rawRepresentation))

// ECDSA
let messageData = "We're all Satoshi.".data(using: .utf8)!
let signature = try! privateKey.ecdsa.signature(for: messageData)

//  DER signature
print(try! signature.derRepresentation.base64EncodedString())

Schnorr

let privateBytes = try! "C90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B14E5C9".bytes
let privateKey = try! secp256k1.Signing.PrivateKey(rawRepresentation: privateBytes)

// Extra params for custom signing
var auxRand = try! "C87AA53824B4D7AE2EB035A2B5BBBCCC080E76CDC6D1692C4B0B62D798E6D906".bytes
var messageDigest = try! "7E2D58D8B3BCDF1ABADEC7829054F90DDA9805AAB56C77333024B9D0A508B75C".bytes

// API allows for signing variable length messages
let signature = try! privateKey.schnorr.signature(message: &messageDigest, auxiliaryRand: &auxRand)

调整 (Tweak)

let privateBytes = try! "C90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B14E5C9".bytes
let privateKey = try! secp256k1.Signing.PrivateKey(rawRepresentation: privateBytes)

// Adding a tweak to the private key and public key
let tweak = try! "5f0da318c6e02f653a789950e55756ade9f194e1ec228d7f368de1bd821322b6".bytes
let tweakedPrivateKey = try! privateKey.tweak(tweak)
let tweakedPublicKeyKey = try! privateKey.publicKey.tweak(tweak)

椭圆曲线迪菲-赫尔曼 (Elliptic Curve Diffie Hellman)

let privateKey = try! secp256k1.KeyAgreement.PrivateKey()
let publicKey = try! secp256k1.KeyAgreement.PrivateKey().publicKey

// Create a shared secret with a private key from only a public key
let sharedSecret = try! privateKey.sharedSecretFromKeyAgreement(with: publicKey)

静默支付 (Silent Payments)

let privateSign1 = try! secp256k1.Signing.PrivateKey()
let privateSign2 = try! secp256k1.Signing.PrivateKey()

let privateKey1 = try! secp256k1.KeyAgreement.PrivateKey(rawRepresentation: privateSign1.rawRepresentation)
let privateKey2 = try! secp256k1.KeyAgreement.PrivateKey(rawRepresentation: privateSign2.rawRepresentation)

let sharedSecret1 = try! privateKey1.sharedSecretFromKeyAgreement(with: privateKey2.publicKey)
let sharedSecret2 = try! privateKey2.sharedSecretFromKeyAgreement(with: privateKey1.publicKey)

let sharedSecretSign1 = try! secp256k1.Signing.PrivateKey(rawRepresentation: sharedSecret1.bytes)
let sharedSecretSign2 = try! secp256k1.Signing.PrivateKey(rawRepresentation: sharedSecret2.bytes)

// Payable Silent Payment public key
let xonlyTweak2 = try! sharedSecretSign2.publicKey.xonly.add(privateSign1.publicKey.xonly.bytes)

// Spendable Silent Payment private key
let privateTweak1 = try! sharedSecretSign1.add(xonly: privateSign1.publicKey.xonly.bytes)

开始使用

此仓库主要使用 Swift 包管理器作为其构建工具，因此我们也建议您使用它。如果您想在自己的项目中依赖 secp256k1.swift，只需将其作为依赖项添加到您的 Package.swift 中即可。

.package(url: "https://github.com/GigaBitcoin/secp256k1.swift.git", .upToNextMajor(from: "0.6.0"))

使用 SPI Playgrounds app 或 🏟 Arena 在 playground 中尝试

arena GigaBitcoin/secp256k1.swift

危险

这些 API 不应被认为是稳定的，并且随时可能更改。libsecp256k1 仍处于实验阶段，尚未正式发布。