[] (https://travis-ci.org/btcsuite/btcec) [![Coverage Status] (https://coveralls.io/repos/btcsuite/btcec/badge.png?branch=master)] (https://coveralls.io/r/btcsuite/btcec?branch=master)

Package btcec implements elliptic curve cryptography needed for working with Bitcoin (secp256k1 only for now). It is designed so that it may be used with the standard crypto/ecdsa packages provided with go. A comprehensive suite of test is provided to ensure proper functionality. Package btcec was originally based on work from ThePiachu which is licensed under the same terms as Go, but it has signficantly diverged since then. The Conformal original is licensed under the liberal ISC license.

This package is one of the core packages from btcd, an alternative full-node implementation of bitcoin which is under active development by Conformal. Although it was primarily written for btcd, this package has intentionally been designed so it can be used as a standalone package for any projects needing to use secp256k1 elliptic curve cryptography.

[] (http://godoc.org/github.com/btcsuite/btcec)

Full go doc style documentation for the project can be viewed online without installing this package by using the GoDoc site here.

You can also view the documentation locally once the package is installed with the godoc tool by running godoc -http=":6060" and pointing your browser to http://localhost:6060/pkg/github.com/btcsuite/btcec

$ go get github.com/btcsuite/btcec

• [Sign Message] (http://godoc.org/github.com/btcsuite/btcec#example-package--SignMessage)
  Demonstrates signing a message with a secp256k1 private key that is first parsed form raw bytes and serializing the generated signature.

• [Verify Signature] (http://godoc.org/github.com/btcsuite/btcec#example-package--VerifySignature)
  Demonstrates verifying a secp256k1 signature against a public key that is first parsed from raw bytes. The signature is also parsed from raw bytes.

All official release tags are signed by Conformal so users can ensure the code has not been tampered with and is coming from Conformal. To verify the signature perform the following:

• Download the public key from the Conformal website at https://opensource.conformal.com/GIT-GPG-KEY-conformal.txt

• Import the public key into your GPG keyring:

  gpg --import GIT-GPG-KEY-conformal.txt

• Verify the release tag with the following command where TAG_NAME is a placeholder for the specific tag:

  git tag -v TAG_NAME

Package btcec is licensed under the copyfree ISC License except for btcec.go and btcec_test.go which is under the same license as Go.