// Copyright (c) 2013-2014 The btcsuite developers
// Copyright (c) 2015-2022 The Decred developers
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.

// Package secp256k1 implements optimized secp256k1 elliptic curve operations in
// pure Go. This is an update that uses the Go 1.16 embed library instead of
// generated code for the data.
//
// This package provides an optimized pure Go implementation of elliptic curve
// cryptography operations over the secp256k1 curve as well as data structures and
// functions for working with public and secret secp256k1 keys.  See
// https://www.secg.org/sec2-v2.pdf for details on the standard.
//
// In addition, sub packages are provided to produce, verify, parse, and serialize
// ECDSA signatures and EC-Schnorr-DCRv0 (a custom Schnorr-based signature scheme
// specific to Decred) signatures.  See the README.md files in the relevant sub
// packages for more details about those aspects.
//
// An overview of the features provided by this package are as follows:
//
//   - Secret key generation, serialization, and parsing
//   - Public key generation, serialization and parsing per ANSI X9.62-1998
//   - Parses uncompressed, compressed, and hybrid public keys
//   - Serializes uncompressed and compressed public keys
//   - Specialized types for performing optimized and constant time field operations
//   - FieldVal type for working modulo the secp256k1 field prime
//   - ModNScalar type for working modulo the secp256k1 group order
//   - Elliptic curve operations in Jacobian projective coordinates
//   - Point addition
//   - Point doubling
//   - Scalar multiplication with an arbitrary point
//   - Scalar multiplication with the base point (group generator)
//   - Point decompression from a given x coordinate
//   - Nonce generation via RFC6979 with support for extra data and version
//     information that can be used to prevent nonce reuse between signing
//     algorithms
//
// It also provides an implementation of the Go standard library crypto/elliptic
// Curve interface via the S256 function so that it may be used with other packages
// in the standard library such as crypto/tls, crypto/x509, and crypto/ecdsa.
// However, in the case of ECDSA, it is highly recommended to use the ecdsa sub
// package of this package instead since it is optimized specifically for secp256k1
// and is significantly faster as a result.
//
// Although this package was primarily written for dcrd, it has intentionally been
// designed so it can be used as a standalone package for any projects needing to
// use optimized secp256k1 elliptic curve cryptography.
//
// Finally, a comprehensive suite of tests is provided to provide a high level of
// quality assurance.
//
// # Use of secp256k1 in Decred
//
// At the time of this writing, the primary public key cryptography in widespread
// use on the Decred network used to secure coins is based on elliptic curves
// defined by the secp256k1 domain parameters.
package secp256k1