ECC.NET

ECC.NET is a .NET Standard library, which implements elliptic-curve primitives (such as curves themselves, points, numeric operations, etc.). It is possible to use included curves, but also create custom ones. Library could be used in .NET Core and .NET Framework solutions.

Features

• included elliptic-curves
  • brainpoolp160r1, brainpoolp192r1, brainpoolp224r1, brainpoolp256r1, brainpoolp320r1, brainpoolp384r1, brainpoolp512r1
  • nistp192, nistp256, nistp384, nistp521
  • secp160r1, secp160r2, secp160k1, secp192r1, secp192k1, secp224r1, secp224k1, secp256r1, secp256k1
• elliptic-curve point operations
• operations with big numbers (Miller–Rabin primality test, cryptografic random number generator, etc.)
• independent of the target architecture
• documentation for vast majority of functions (included in code)
• simple usage

Architecture

ECC.NET solution
+-- ECC.NET
|   +-- Commons.cs                              (common objects to more ECC.NET classes)
|   +-- Cryptography.cs                         (cryptographic functions using elliptic-curves)
|   +-- Curve.cs                                (ECC.NET elliptic-curve class)
|   +-- Numerics.cs                             (operations with big numbers)
|   +-- Point.cs                                (ECC.NET elliptic-curve point class)
+-- ECC.NET.Exceptions
|   +-- CurvesMismatchException.cs              (one of the points has different curve instance assigned)
|   +-- GreatestCommonDivisorException.cs       (unwanted greatest common divisor value)
|   +-- InvalidPointException.cs                (point is not on appropriate curve)
|   +-- UnknownCurveException.cs                (usage of unknown elliptic-curve name)
+-- ECC.NET.Test
    +-- Program.cs                              (sequence of ECC.NET tests)

Examples

These are some examples of basic ECC.NET usage. All examples follow each other...

Curve instantiation (secp256r1)

Curve curve = new Curve(Curve.Names.secp256r1);

Multiplication of elliptic-curve specific point G by random number

BigInteger r = Numerics.GetNumberFromGroup(curve.N, curve.Length);
Point multipliedG = Point.Multuply(r, curve.G);

Add two points

Point addedPoints = Point.Add(multipliedG, curve.G);

Elliptic-curve Diffie–Hellman

Cryptography.KeyPair aliceKeyPair = Cryptography.GetKeyPair(curve);
Cryptography.KeyPair bobKeyPair = Cryptography.GetKeyPair(curve);

Point aliceSharedSecret = Cryptography.GetSharedSecret(aliceKeyPair.PrivateKey, bobKeyPair.PublicKey);
Point bobSharedSecret = Cryptography.GetSharedSecret(bobKeyPair.PrivateKey, aliceKeyPair.PublicKey);

References

• EllipticCurveCrypto (https://github.com/majunkang/EllipticCurveCrypto) under MIT License (https://github.com/majunkang/EllipticCurveCrypto/blob/master/LICENSE) as inspiration