2021-04-21 12:50:07 +00:00
<!DOCTYPE html> < html lang = "en" > < head > < meta charSet = "utf-8" / > < meta http-equiv = "X-UA-Compatible" content = "IE=edge" / > < title > Secp256k1 · bitcoin-s< / title > < meta name = "viewport" content = "width=device-width, initial-scale=1.0" / > < meta name = "generator" content = "Docusaurus" / > < meta name = "description" content = "[Libsecp256k1](https://github.com/bitcoin-core/secp256k1) is used to preform cryptographic operations on the secp256k1 curve." / > < meta name = "docsearch:version" content = "next" / > < meta name = "docsearch:language" content = "en" / > < meta property = "og:title" content = "Secp256k1 · bitcoin-s" / > < meta property = "og:type" content = "website" / > < meta property = "og:url" content = "https://bitcoin-s.org/" / > < meta property = "og:description" content = "[Libsecp256k1](https://github.com/bitcoin-core/secp256k1) is used to preform cryptographic operations on the secp256k1 curve." / > < meta property = "og:image" content = "https://bitcoin-s.org/img/undraw_online.svg" / > < meta name = "twitter:card" content = "summary" / > < meta name = "twitter:image" content = "https://bitcoin-s.org/img/undraw_tweetstorm.svg" / > < link rel = "shortcut icon" href = "/img/favicon.ico" / > < link rel = "stylesheet" href = "https://cdn.jsdelivr.net/docsearch.js/1/docsearch.min.css" / > < link rel = "stylesheet" href = "//cdnjs.cloudflare.com/ajax/libs/highlight.js/9.12.0/styles/default.min.css" / > < script >
2020-04-02 12:36:04 +00:00
(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
})(window,document,'script','https://www.google-analytics.com/analytics.js','ga');
ga('create', 'UA-61958686-2', 'auto');
ga('send', 'pageview');
2023-11-22 16:47:32 +00:00
< / script > < link rel = "stylesheet" href = "/css/code-block-buttons.css" / > < script type = "text/javascript" src = "https://buttons.github.io/buttons.js" > < / script > < script type = "text/javascript" src = "https://cdnjs.cloudflare.com/ajax/libs/clipboard.js/2.0.0/clipboard.min.js" > < / script > < script type = "text/javascript" src = "https://fonts.googleapis.com/css?family=Montserrat:500" > < / script > < script type = "text/javascript" src = "https://www.googletagmanager.com/gtag/js?id=UA-61958686-2" > < / script > < script type = "text/javascript" src = "/js/code-block-buttons.js" > < / script > < script src = "/js/scrollSpy.js" > < / script > < link rel = "stylesheet" href = "/css/main.css" / > < script src = "/js/codetabs.js" > < / script > < / head > < body class = "sideNavVisible separateOnPageNav" > < div class = "fixedHeaderContainer" > < div class = "headerWrapper wrapper" > < header > < a href = "/" > < img class = "logo" src = "/img/favicon.ico" alt = "bitcoin-s" / > < h2 class = "headerTitleWithLogo" > bitcoin-s< / h2 > < / a > < a href = "/versions" > < h3 > next< / h3 > < / a > < div class = "navigationWrapper navigationSlider" > < nav class = "slidingNav" > < ul class = "nav-site nav-site-internal" > < li class = "siteNavGroupActive" > < a href = "/docs/next/core/core-intro" target = "_self" > Docs< / a > < / li > < li class = "" > < a href = "/download" target = "_self" > Download< / a > < / li > < li class = "" > < a href = "/api/org/bitcoins" target = "_self" > API< / a > < / li > < li class = "" > < a href = "/help" target = "_self" > Help< / a > < / li > < li class = "navSearchWrapper reactNavSearchWrapper" > < input type = "text" id = "search_input_react" placeholder = "Search" title = "Search" / > < / li > < / ul > < / nav > < / div > < / header > < / div > < / div > < div class = "navPusher" > < div class = "docMainWrapper wrapper" > < div class = "docsNavContainer" id = "docsNav" > < nav class = "toc" > < div class = "toggleNav" > < section class = "navWrapper wrapper" > < div class = "navBreadcrumb wrapper" > < div class = "navToggle" id = "navToggler" > < div class = "hamburger-menu" > < div class = "line1" > < / div > < div class = "line2" > < / div > < div class = "line3" > < / div > < / div > < / div > < h2 > < i > › < / i > < span > Secp256k1< / span > < / h2 > < div class = "tocToggler" id = "tocToggler" > < i class = "icon-toc" > < / i > < / div > < / div > < div class = "navGroups" > < div class = "navGroup" > < h3 class = "navGroupCategoryTitle" > Getting Started< / h3 > < ul class = "" > < li class = "navListItem" > < a class = "navItem" href = "/docs/next/getting-started" > Intro and Getting Started< / a > < / li > < li class = "navListItem" > < a class = "navItem" href = "/docs/next/bips" > Supported BIPs< / a > < / li > < / ul > < / div > < div class = "navGroup" > < h3 class = "navGroupCategoryTitle" > Getting Setup< / h3 > < ul class = "" > < li class = "navListItem" > < a class = "navItem" href = "/docs/next/getting-setup" > Getting Bitcoin-S installed on your machine< / a > < / li > < li class = "navListItem" > < a class = "navItem" href = "/docs/next/ui-setup" > Installing the DLC Wallet UI< / a > < / li > < / ul > < / div > < div class = "navGroup" > < h3 class = "navGroupCategoryTitle" > Applications< / h3 > < ul class = "" > < li class = "navListItem" > < a class = "navItem" href = "/docs/next/applications/cli" > CLI< / a > < / li > < li class = "navListItem" > < a class = "navItem" href = "/docs/next/applications/server" > Application Server< / a > < / li > < li class = "navListItem" > < a class = "navItem" href = "/docs/next/applications/gui" > GUI< / a > < / li > < li class = "navListItem" > < a class = "navItem" href = "/docs/next/applications/server-systemd" > Systemd installation< / a > < / li > < / ul > < / div > < div class = "navGroup" > < h3 class = "navGroupCategoryTitle" > Chain< / h3 > < ul class = "" > < li class = "navListItem" > < a class = "navItem" href = "/docs/next/chain/chain" > Blockchain Verification< / a > < / li > < li class = "navListItem" > < a class = "navItem" href = "/docs/next/chain/filter-sync" > Syncing Blockfilters< / a > < / li > < li class = "navListItem" > < a class = "navItem" href = "/docs/next/chain/chain-query-api" > Chain Query API< / a > < / li > < / ul > < / div > < div class = "navGroup" > < h3 class = "navGroupCategoryTitle" > Configuration< / h3 > < ul class = "" > < li class = "navListItem" > < a class = "navItem" href = "/docs/next/config/configuration" > Application Configuration< / a > < / li > < / ul > < / div > < div class = "navGroup" > < h3 class = "navGroupCategoryTitle" > Core Module< / h3 > < ul class = "" > < li class = "navListItem" > < a class = "navItem" href = "/docs/next/core/core-intro" > Core Module< / a > < / li > < li class = "navListItem" > < a class = "navItem" href = "/docs/next/core/addresses" > Generating Addresses< / a > < /l
2020-03-18 11:48:02 +00:00
var coll = document.getElementsByClassName('collapsible');
var checkActiveCategory = true;
for (var i = 0; i < coll.length ; i + + ) {
var links = coll[i].nextElementSibling.getElementsByTagName('*');
if (checkActiveCategory){
for (var j = 0; j < links.length ; j + + ) {
if (links[j].classList.contains('navListItemActive')){
coll[i].nextElementSibling.classList.toggle('hide');
coll[i].childNodes[1].classList.toggle('rotate');
checkActiveCategory = false;
break;
}
}
}
coll[i].addEventListener('click', function() {
var arrow = this.childNodes[1];
arrow.classList.toggle('rotate');
var content = this.nextElementSibling;
content.classList.toggle('hide');
});
}
document.addEventListener('DOMContentLoaded', function() {
createToggler('#navToggler', '#docsNav', 'docsSliderActive');
createToggler('#tocToggler', 'body', 'tocActive');
var headings = document.querySelector('.toc-headings');
headings & & headings.addEventListener('click', function(event) {
var el = event.target;
while(el !== headings){
if (el.tagName === 'A') {
document.body.classList.remove('tocActive');
break;
} else{
el = el.parentNode;
}
}
}, false);
function createToggler(togglerSelector, targetSelector, className) {
var toggler = document.querySelector(togglerSelector);
var target = document.querySelector(targetSelector);
if (!toggler) {
return;
}
toggler.onclick = function(event) {
event.preventDefault();
target.classList.toggle(className);
};
}
});
< / script > < / nav > < / div > < div class = "container mainContainer docsContainer" > < div class = "wrapper" > < div class = "post" > < header class = "postHeader" > < a class = "edit-page-link button" href = "https://github.com/bitcoin-s/bitcoin-s/blob/master/docs/secp256k1/secp256k1.md" target = "_blank" rel = "noreferrer noopener" > Edit< / a > < h1 id = "__docusaurus" class = "postHeaderTitle" > Secp256k1< / h1 > < / header > < article > < div > < span > < p > < a href = "https://github.com/bitcoin-core/secp256k1" > Libsecp256k1< / a > is used to preform cryptographic operations on the secp256k1 curve.
This is the curve that bitcoin uses. There is a < em > signficant< / em > speedup when using this library compared to java crypto libraries
like bouncy castle.< / p >
< p > In bitcoin-s, we support native binaries for libsecp256k1< / p >
< ol >
< li > < a href = "../../secp256k1jni/natives/linux_32" > linux 32 bit< / a > < / li >
< li > < a href = "../../secp256k1jni/natives/linux_64" > linux 64 bit< / a > < / li >
< li > < a href = "../../secp256k1jni/natives/osx_64" > mac osx 64 bit< / a > < / li >
< li > < a href = "../../secp256k1jni/natives/windows_64" > windows 64 bit< / a > < / li >
< / ol >
< p > Bitcoin-s uses a zero dependency library called < a href = "https://github.com/scijava/native-lib-loader" > < code > native-lib-loader< / code > < / a > .
That does the appropriate loading of the library onto your classpath to be accessed.< / p >
2020-04-20 18:04:35 +00:00
< h3 > < a class = "anchor" aria-hidden = "true" id = "using-libsecp256k1" > < / a > < a href = "#using-libsecp256k1" aria-hidden = "true" class = "hash-link" > < svg class = "hash-link-icon" aria-hidden = "true" height = "16" version = "1.1" viewBox = "0 0 16 16" width = "16" > < path fill-rule = "evenodd" d = "M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z" > < / path > < / svg > < / a > Using libsecp256k1< / h3 >
2020-03-18 11:48:02 +00:00
< p > To tell if you have access to libsecp256k1 you can do the following< / p >
< pre > < code class = "hljs css language-scala" > < span class = "hljs-keyword" > val< / span > isEnabled = org.bitcoin.< span class = "hljs-type" > Secp256k1Context< / span > .isEnabled()
2021-02-02 13:37:52 +00:00
println(< span class = "hljs-string" > s"Secp256k1Context.isEnabled=< span class = "hljs-subst" > ${isEnabled}< / span > "< / span > )
2020-03-18 11:48:02 +00:00
< / code > < / pre >
2020-08-27 19:49:50 +00:00
< p > If libsecp256k1 is enabled, you can use < a href = "/api/org/bitcoin/NativeSecp256k1" > NativeSecp256k1< / a >
2020-03-18 11:48:02 +00:00
with static method defined in the class.< / p >
< pre > < code class = "hljs css language-scala" > < span class = "hljs-keyword" > val< / span > privKey = < span class = "hljs-type" > ECPrivateKey< / span > .freshPrivateKey
< span class = "hljs-keyword" > val< / span > pubKey = privKey.publicKey
< span class = "hljs-keyword" > val< / span > dataToSign = < span class = "hljs-type" > DoubleSha256Digest< / span > .empty
< span class = "hljs-keyword" > val< / span > signature = < span class = "hljs-type" > NativeSecp256k1< / span > .sign(dataToSign.bytes.toArray, privKey.bytes.toArray)
< span class = "hljs-keyword" > val< / span > verify = < span class = "hljs-type" > NativeSecp256k1< / span > .verify(dataToSign.bytes.toArray, signature, pubKey.bytes.toArray)
2021-02-02 13:37:52 +00:00
println(< span class = "hljs-string" > s"Verified with NativeSecp256k1 signature=< span class = "hljs-subst" > ${verify}< / span > "< / span > )
2020-03-18 11:48:02 +00:00
< span class = "hljs-comment" > //you can also just directly sign with the ECKey interface:< / span >
< span class = "hljs-keyword" > val< / span > signature2 = privKey.sign(dataToSign)
< span class = "hljs-keyword" > val< / span > verified2 = pubKey.verify(dataToSign, signature2)
2021-02-02 13:37:52 +00:00
println(< span class = "hljs-string" > s"Verified with NativeSecp256k1 again=< span class = "hljs-subst" > ${verified2}< / span > "< / span > )
2020-03-18 11:48:02 +00:00
< / code > < / pre >
< h3 > < a class = "anchor" aria-hidden = "true" id = "when-libsecp256k1-isnt-available-or-you-want-to-turn-it-off" > < / a > < a href = "#when-libsecp256k1-isnt-available-or-you-want-to-turn-it-off" aria-hidden = "true" class = "hash-link" > < svg class = "hash-link-icon" aria-hidden = "true" height = "16" version = "1.1" viewBox = "0 0 16 16" width = "16" > < path fill-rule = "evenodd" d = "M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z" > < / path > < / svg > < / a > When libsecp256k1 isn't available, or you want to turn it off< / h3 >
< p > There are two reasons you wouldn't want to use libsecp256k1< / p >
< ol >
< li > You don't trust the pre-compiled binaries we are using< / li >
< li > Your OS/arch is not supported< / li >
< / ol >
< p > There are two ways you can circumvent libsecp256k1< / p >
< ol >
2020-05-26 18:20:03 +00:00
< li > Set < code > DISABLE_SECP256K1=true< / code > in your environment variables. This will force < code > CryptoContext.default< / code > to return false which will make Bitcoin-S act like < code > Secp256k1Context.isEnabled()< / code > has returned false.< / li >
2020-03-18 11:48:02 +00:00
< li > Call Bouncy castle methods in < code > ECKey< / code > .< / li >
< / ol >
< p > Here is an example of calling bouncy castle methods in < code > ECKey< / code > < / p >
< pre > < code class = "hljs css language-scala" > < span class = "hljs-keyword" > val< / span > privKey = < span class = "hljs-type" > ECPrivateKey< / span > .freshPrivateKey
2021-05-06 18:44:01 +00:00
< span class = "hljs-comment" > // privKey: ECPrivateKey = Masked(ECPrivateKey)< / span >
2021-03-02 15:32:56 +00:00
< span class = "hljs-comment" > // calls bouncy castle indirectly via CryptoContext< / span >
< span class = "hljs-keyword" > val< / span > publicKey = privKey.publicKey
2025-03-03 12:56:08 +00:00
< span class = "hljs-comment" > // publicKey: ECPublicKey = ECPublicKey(03206628c00ff0c7555e137356f9363f73c08065d5f275dcb5ba0f3e313796b118)< / span >
2020-03-18 11:48:02 +00:00
< span class = "hljs-keyword" > val< / span > dataToSign = < span class = "hljs-type" > DoubleSha256Digest< / span > .empty
< span class = "hljs-comment" > // dataToSign: DoubleSha256Digest = DoubleSha256Digest(0000000000000000000000000000000000000000000000000000000000000000)< / span >
2021-03-02 15:32:56 +00:00
< span class = "hljs-comment" > // calls bouncy castle indirectly via CryptoContext< / span >
< span class = "hljs-keyword" > val< / span > signature = privKey.sign(dataToSign.bytes)
2025-03-03 12:56:08 +00:00
< span class = "hljs-comment" > // signature: ECDigitalSignature = ECDigitalSignature(3044022004c4e8e49efd57002f50dd3e9af633e17f23db3d7dc11bffe9aa300c58ee498602202db62786ff58a3b449cefee7047b5a630cb5d5dbfd863e964dd5953e3f39f52e)< / span >
2020-03-18 11:48:02 +00:00
2021-03-02 15:32:56 +00:00
< span class = "hljs-comment" > // calls bouncy castle indirectly via CryptoContext< / span >
< span class = "hljs-keyword" > val< / span > verified = publicKey.verify(dataToSign.bytes, signature)
2020-03-18 11:48:02 +00:00
< span class = "hljs-comment" > // verified: Boolean = true< / span >
2021-02-02 13:37:52 +00:00
println(< span class = "hljs-string" > s"Verified with bouncy castle=< span class = "hljs-subst" > ${verified}< / span > "< / span > )
2020-03-18 11:48:02 +00:00
< span class = "hljs-comment" > // Verified with bouncy castle=true< / span >
< / code > < / pre >
2020-04-20 18:04:35 +00:00
< h3 > < a class = "anchor" aria-hidden = "true" id = "building-libsecp256k1" > < / a > < a href = "#building-libsecp256k1" aria-hidden = "true" class = "hash-link" > < svg class = "hash-link-icon" aria-hidden = "true" height = "16" version = "1.1" viewBox = "0 0 16 16" width = "16" > < path fill-rule = "evenodd" d = "M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z" > < / path > < / svg > < / a > Building libsecp256k1< / h3 >
< p > < a href = "/docs/next/secp256k1/jni-modify#adding-to-bitcoin-s" > See instructions here< / a > < / p >
2025-01-01 16:02:04 +00:00
< / span > < / div > < / article > < / div > < div class = "docs-prevnext" > < a class = "docs-prev button" href = "/docs/next/rpc/lnd-rpc" > < span class = "arrow-prev" > ← < / span > < span > LND< / span > < / a > < a class = "docs-next button" href = "/docs/next/secp256k1/jni-modify" > < span > Adding to Secp256k1 JNI< / span > < span class = "arrow-next" > →< / span > < / a > < / div > < / div > < / div > < nav class = "onPageNav" > < / nav > < / div > < footer class = "nav-footer" id = "footer" > < section class = "sitemap" > < a href = "/" class = "nav-home" > < img src = "/img/favicon.ico" alt = "bitcoin-s" width = "66" height = "58" / > < / a > < div > < h5 > Docs< / h5 > < a href = "/docs/en/getting-started" > Getting Started< / a > < a href = "/docs/en/core/core-intro" > Guides< / a > < a href = "/api/org/bitcoins" > API Reference< / a > < / div > < div > < h5 > Community< / h5 > < a href = "/en/users.html" > User Showcase< / a > < a href = "https://join.slack.com/t/suredbits/shared_invite/zt-eavycu0x-WQL7XOakzQo8tAy7jHHZUw" target = "_blank" rel = "noreferrer noopener" > Slack< / a > < a href = "https://gitter.im/bitcoin-s-core/" > Gitter chat< / a > < / div > < div > < h5 > More< / h5 > < a href = "https://github.com/bitcoin-s/bitcoin-s" > GitHub< / a > < a class = "github-button" href = "https://github.com/bitcoin-s/bitcoin-s" data-icon = "octicon-star" data-count-href = "/bitcoin-s/bitcoin-s-core/stargazers" data-show-count = "true" data-count-aria-label = "# stargazers on GitHub" aria-label = "Star this project on GitHub" > Star< / a > < / div > < / section > < section class = "copyright" > Copyright © 2025 Suredbits & the bitcoin-s developers< / section > < / footer > < / div > < script type = "text/javascript" src = "https://cdn.jsdelivr.net/docsearch.js/1/docsearch.min.js" > < / script > < script >
2020-03-18 11:48:02 +00:00
document.addEventListener('keyup', function(e) {
if (e.target !== document.body) {
return;
}
// keyCode for '/' (slash)
if (e.keyCode === 191) {
const search = document.getElementById('search_input_react');
search & & search.focus();
}
});
< / script > < script >
var search = docsearch({
apiKey: '0a510688bf8448e19aeb380377d328d3',
indexName: 'bitcoin-s',
inputSelector: '#search_input_react'
});
< / script > < / body > < / html >
