EllipticSwift 2.0.7

EllipticSwift 2.0.7

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Maintained by Alex Vlasov.

EllipticSwift 2.0.7

EllipticSwift

Installation

Add the following line to your Podfile

  pod 'EllipticSwift', '~> 2.0'

Example

let curve = secp256k1Curve
        let generatorX = BigUInt("79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798", radix: 16)!
        let generatorY = BigUInt("483ADA7726A3C4655DA4FBFC0E1108A8FD17B448A68554199C47D08FFB10D4B8", radix: 16)!
        let success = curve.testGenerator(AffineCoordinates(generatorX, generatorY))
        XCTAssert(success, "Failed to init secp256k1 curve!")
        
        // this is basically a private key - large random scalar
        let randomScalar = BigUInt.randomInteger(lessThan: 256)
        guard let privateKey = U256(randomScalar.serialize()) else { return XCTFail()}
        
        // make point. Point is made from affine coordinates in normal (not Montgomery) representation
        guard let G = curve.toPoint(generatorX, generatorY) else {return XCTFail()}
        
        // calculate a public key
        let publicKey = privateKey * G
        XCTAssert(!publicKey.isInfinity)
        
        // also try to multiply by group order
        let groupOrder = curve.order
        let expectInfinity = groupOrder * G
        XCTAssert(expectInfinity.isInfinity)

Limitations

  • Point multiplication is not yet constant type
  • Protocols are quite suboptimal, global cleanups will happen
  • No support of pairings yet
  • U512 type is not polyfilled
  • No Montgomery support on iOS (should work, but untested)
  • Only Weierstrass curves for now