starkbank-ecdsa 1.3.3

.NET Standard 1.3 .NET Framework 4.0
dotnet add package starkbank-ecdsa --version 1.3.3
NuGet\Install-Package starkbank-ecdsa -Version 1.3.3
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.
<PackageReference Include="starkbank-ecdsa" Version="1.3.3" />
For projects that support PackageReference, copy this XML node into the project file to reference the package.
paket add starkbank-ecdsa --version 1.3.3
#r "nuget: starkbank-ecdsa, 1.3.3"
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package.
// Install starkbank-ecdsa as a Cake Addin
#addin nuget:?package=starkbank-ecdsa&version=1.3.3

// Install starkbank-ecdsa as a Cake Tool
#tool nuget:?package=starkbank-ecdsa&version=1.3.3

A lightweight and fast ECDSA implementation


This is a pure C# implementation of the Elliptic Curve Digital Signature Algorithm. It is compatible with .NET Standard 1.3, 2.0 & 2.1. It is also compatible with OpenSSL. It uses some elegant math such as Jacobian Coordinates to speed up the ECDSA on pure C#.


To install StarkBank`s ECDSA-DotNet, get the package on nugget.


We currently support secp256k1, but it's super easy to add more curves to the project. Just add them on curve.cs


We ran a test on Node 13.1.0 on a MAC Pro i5 2019. The libraries ran 100 times and showed the average times displayed bellow:

Library sign verify
starkbank-ecdsa 3.5ms 6.5ms
nethereum 8.5ms 2.5ms

Sample Code

How to sign a json message for Stark Bank:

using System;
using EllipticCurve;

// Generate privateKey from PEM string
PrivateKey privateKey = PrivateKey.fromPem("-----BEGIN EC PARAMETERS-----\nBgUrgQQACg==\n-----END EC PARAMETERS-----\n-----BEGIN EC PRIVATE KEY-----\nMHQCAQEEIODvZuS34wFbt0X53+P5EnSj6tMjfVK01dD1dgDH02RzoAcGBSuBBAAK\noUQDQgAE/nvHu/SQQaos9TUljQsUuKI15Zr5SabPrbwtbfT/408rkVVzq8vAisbB\nRmpeRREXj5aog/Mq8RrdYy75W9q/Ig==\n-----END EC PRIVATE KEY-----\n");

// Create message from json
string message = "{\n    \"transfers\": [\n        {\n            \"amount\": 100000000,\n            \"taxId\": \"594.739.480-42\",\n            \"name\": \"Daenerys Targaryen Stormborn\",\n            \"bankCode\": \"341\",\n            \"branchCode\": \"2201\",\n            \"accountNumber\": \"76543-8\",\n            \"tags\": [\"daenerys\", \"targaryen\", \"transfer-1-external-id\"]\n        }\n    ]\n}";

Signature signature = Ecdsa.sign(message, privateKey);

// Generate Signature in base64. This result can be sent to Stark Bank in header as Digital-Signature parameter

// To double check if message matches the signature
PublicKey publicKey = privateKey.publicKey();

Console.WriteLine(Ecdsa.verify(message, signature, publicKey));

Simple use:

using System;
using EllipticCurve;

// Generate new Keys
PrivateKey privateKey = new PrivateKey();
PublicKey publicKey = privateKey.publicKey();

string message = "My test message";

// Generate Signature
Signature signature = Ecdsa.sign(message, privateKey);

// Verify if signature is valid
Console.WriteLine(Ecdsa.verify(message, signature, publicKey));


This library is compatible with OpenSSL, so you can use it to generate keys:

openssl ecparam -name secp256k1 -genkey -out privateKey.pem
openssl ec -in privateKey.pem -pubout -out publicKey.pem

Create a message.txt file and sign it:

openssl dgst -sha256 -sign privateKey.pem -out signatureDer.txt message.txt

It's time to verify:

using System;
using EllipticCurve;

string publicKeyPem ="publicKey.pem");
byte[] signatureDer = EllipticCurve.Utils.File.readBytes("signatureDer.txt");
string message ="message.txt");

PublicKey publicKey = PublicKey.fromPem(publicKeyPem);
Signature signature = Signature.fromDer(signatureDer);

Console.WriteLine(Ecdsa.verify(message, signature, publicKey));

You can also verify it on terminal:

openssl dgst -sha256 -verify publicKey.pem -signature signatureDer.txt message.txt

NOTE: If you want to create a Digital Signature to use in the Stark Bank, you need to convert the binary signature to base64.

openssl base64 -in signatureDer.txt -out signatureBase64.txt

With this library, you can do it:

using System;
using EllipticCurve;

byte[] signatureDer = EllipticCurve.Utils.File.readBytes("signatureDer.txt");

Signature signature = Signature.fromDer(signatureDer);


Run all unit tests

Run StarkbankEcdsaTests on XUnit in Visual Studio

Product Versions
.NET net5.0 net5.0-windows net6.0 net6.0-android net6.0-ios net6.0-maccatalyst net6.0-macos net6.0-tvos net6.0-windows net7.0 net7.0-android net7.0-ios net7.0-maccatalyst net7.0-macos net7.0-tvos net7.0-windows
.NET Core netcoreapp1.0 netcoreapp1.1 netcoreapp2.0 netcoreapp2.1 netcoreapp2.2 netcoreapp3.0 netcoreapp3.1
.NET Standard netstandard1.3 netstandard1.4 netstandard1.5 netstandard1.6 netstandard2.0 netstandard2.1
.NET Framework net40 net403 net45 net451 net452 net46 net461 net462 net463 net47 net471 net472 net48 net481
MonoAndroid monoandroid
MonoMac monomac
MonoTouch monotouch
Tizen tizen30 tizen40 tizen60
Universal Windows Platform uap uap10.0
Xamarin.iOS xamarinios
Xamarin.Mac xamarinmac
Xamarin.TVOS xamarintvos
Xamarin.WatchOS xamarinwatchos
Compatible target framework(s)
Additional computed target framework(s)
Learn more about Target Frameworks and .NET Standard.
  • .NETFramework 4.0

    • No dependencies.
  • .NETFramework 4.5.2

    • No dependencies.
  • .NETStandard 1.3

  • .NETStandard 2.0

    • No dependencies.
  • .NETStandard 2.1

    • No dependencies.

NuGet packages (10)

Showing the top 5 NuGet packages that depend on starkbank-ecdsa:

Package Downloads
SendGrid The ID prefix of this package has been reserved for one of the owners of this package by

C# client library and examples for using Twilio SendGrid API's to send mail and access Web API v3 endpoints with .NET Standard 1.3 and .NET Core support.


WATG library of commonly used and shared functionalities


SDK to facilitate C# (.NET) integrations with the Stark Bank API


Package Description


C# client library and examples for using Twilio SendGrid API's to send mail and access Web API v3 endpoints with .NET Standard 1.3 and .NET Core support.

GitHub repositories (1)

Showing the top 1 popular GitHub repositories that depend on starkbank-ecdsa:

Repository Stars
The Official Twilio SendGrid C#, .NetStandard, .NetCore API Library
Version Downloads Last updated
1.3.3 15,797,986 11/9/2021
1.3.2 106,880 11/4/2021
1.3.1 7,232,386 4/6/2021
1.3.0 85,248 1/26/2021
1.2.1 175,398 9/27/2020
1.2.0 13,434,082 6/23/2020
1.1.0 2,062 5/12/2020
1.0.0 2,051 4/15/2020
0.0.1 1,017 1/7/2020