diff --git a/.gitignore b/.gitignore
index 3777eb7..ffe9778 100644
--- a/.gitignore
+++ b/.gitignore
@@ -60,3 +60,6 @@ typings/
 # next.js build output
 .next
 .idea/
+
+# php
+vendor
diff --git a/composer.json b/composer.json
new file mode 100644
index 0000000..0c95d0e
--- /dev/null
+++ b/composer.json
@@ -0,0 +1,23 @@
+{
+    "name": "wulkanowy/uonet-request-signer",
+    "description": "UONET+ Request Signer",
+    "type": "library",
+    "license": "MIT",
+    "authors": [
+        {
+            "name": "Mikołaj Pich",
+            "email": "m.pich@outlook.com"
+        }
+    ],
+    "require": {
+        "php": "^7.0"
+    },
+    "autoload": {
+        "files": [
+            "php/src/signer.php"
+        ]
+    },
+    "scripts": {
+        "test": "php php/tests/signer_test.php"
+    }
+}
diff --git a/composer.lock b/composer.lock
new file mode 100644
index 0000000..7779b05
--- /dev/null
+++ b/composer.lock
@@ -0,0 +1,19 @@
+{
+    "_readme": [
+        "This file locks the dependencies of your project to a known state",
+        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
+        "This file is @generated automatically"
+    ],
+    "content-hash": "d1e5ca66a91f32aba91951d63ead0797",
+    "packages": [],
+    "packages-dev": [],
+    "aliases": [],
+    "minimum-stability": "stable",
+    "stability-flags": [],
+    "prefer-stable": false,
+    "prefer-lowest": false,
+    "platform": {
+        "php": "^7.0"
+    },
+    "platform-dev": []
+}
diff --git a/index.html b/index.html
index 514bb5d..65c02a3 100644
--- a/index.html
+++ b/index.html
@@ -5,7 +5,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1">
     <title>UONET+ Request Signer by Wulkanowy</title>
     <script src="https://cdnjs.cloudflare.com/ajax/libs/forge/0.7.5/forge.min.js" integrity="sha256-Nxwt1mmv6marltfJxJp/8QzIDEMTrGXI2fKG50K67ao=" crossorigin="anonymous"></script>
-    <script src="signer.js" defer></script>
+    <script src="js/signer.js" defer></script>
 
     <script src="https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.39.2/codemirror.min.js" integrity="sha256-uRIJ6Wfou5cTtmcCvQNA9lvsYl8sUbZXxnfG+P79ssY=" crossorigin="anonymous"></script>
     <script src="https://cdnjs.cloudflare.com/ajax/libs/codemirror/5.39.2/mode/javascript/javascript.min.js" integrity="sha256-soPk2bgFhLwixxuyUzaWVadUMcVwWNE5JZwYdQhL4Xk=" crossorigin="anonymous"></script>
@@ -58,6 +58,7 @@
     <footer class="footer">
         &copy; 2018 by <a href="https://wulkanowy.github.io">Wulkanowy</a> |
         <a href="https://github.com/wulkanowy/uonet-request-signer">GitHub</a> |
+        <a href="https://github.com/wulkanowy/uonet-request-signer/blob/master/src/php">PHP implementation</a> |
         <a href="https://github.com/VLO-GDA/uonet-sdk/blob/master/src/main/java/net/maciekmm/uonet/EncryptionUtils.java">Java implementation</a>
     </footer>
     <script>
diff --git a/signer.js b/js/signer.js
similarity index 100%
rename from signer.js
rename to js/signer.js
diff --git a/php/README.md b/php/README.md
new file mode 100644
index 0000000..af55165
--- /dev/null
+++ b/php/README.md
@@ -0,0 +1,17 @@
+# Uonet+ request signer for PHP
+
+[![Total Downloads](https://poser.pugx.org/wulkanowy/uonet-request-signer/downloads?format=flat-square)](https://packagist.org/packages/wulkanowy/uonet-request-signer)
+
+## Instalation
+
+Via composer:
+
+```bash
+$ composer require wulkanowy/uonet-request-signer
+```
+
+## Tests
+
+```bash
+$ composer test
+```
diff --git a/php/src/signer.php b/php/src/signer.php
new file mode 100644
index 0000000..02307f0
--- /dev/null
+++ b/php/src/signer.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace Wulkanowy\UonetRequestSigner;
+
+function signContent(string $password, string $certificate, string $content)
+{
+    openssl_pkcs12_read(base64_decode($certificate), $keystore, $password);
+
+    if (null === $keystore) {
+        throw new \RuntimeException('Invalid password');
+    }
+
+    $privateKey = openssl_pkey_get_private($keystore['pkey'], $password);
+
+    openssl_sign($content, $signature, $privateKey, OPENSSL_ALGO_SHA1);
+
+    return base64_encode($signature);
+}
diff --git a/php/tests/signer_test.php b/php/tests/signer_test.php
new file mode 100644
index 0000000..3fd1a57
--- /dev/null
+++ b/php/tests/signer_test.php
@@ -0,0 +1,18 @@
+<?php
+
+use function Wulkanowy\UonetRequestSigner\signContent;
+
+require_once dirname(__DIR__).'/../vendor/autoload.php';
+
+$password          = '012345678901234567890123456789AB';
+$certificate       = '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';
+$content           = '{}';
+$expectedSignature = 'PeEBjuVV4iI/bF5ljIBeTEhS/0htSsDsTQtExVYvX4dn9UJtZJZOYiVQZRLQHRv0sYmAufF9FqK/w+8wavUS0JdaehLewOAX/ppgxlyg3O1U/yYm7hwpGppoSh15M5hnFtBu7kEEJAb1akPACL64GEfAemfkyJVq5lab5W/1+oCQRdFePwLkrP1k8MQiMLYYPGY4+Sb/UEr4TmgahMwE9ZUVS+8NAxyi5sTwrejzvCl7/Z5o6mAtl5zFSxCgocKldVn/+A8z0/v87p4Zf5dgLCYcV+CLE+gEw22lFuBG3tnmfq3O4YBpg72RDvu5lYT0DLIHtUdibskB2GRNg3gDig==';
+
+$requestSignatureValue = signContent($password, $certificate, $content);
+
+if ($requestSignatureValue !== $expectedSignature) {
+    throw new AssertionError('Signatures not match');
+}
+
+echo 'Signatures match'.PHP_EOL;