diff --git a/README.md b/README.md
index b74d8a35..fc9a23a1 100644
--- a/README.md
+++ b/README.md
@@ -48,9 +48,10 @@ $token = (new Builder())->setIssuer('http://example.com') // Configures the issu
                         ->getToken(); // Retrieves the generated token
 
 
-$token->getHeader(); // Retrieves the token header
+$token->getHeaders(); // Retrieves the token headers
 $token->getClaims(); // Retrieves the token claims
 
+echo $token->getHeader('jti'); // will print "4f1g23a12aa"
 echo $token->getClaim('iss'); // will print "http://example.com"
 echo $token->getClaim('uid'); // will print "1"
 echo $token; // The string representation of the object is a JWT string (pretty easy, right?)
@@ -64,9 +65,10 @@ Use the parser to create a new token from a JWT string (using the previous token
 use Lcobucci\JWT\Parser;
 
 $token = (new Parser())->parse((string) $token); // Parses from a string
-$token->getHeader(); // Retrieves the token header
+$token->getHeaders(); // Retrieves the token header
 $token->getClaims(); // Retrieves the token claims
 
+echo $token->getHeader('jti'); // will print "4f1g23a12aa"
 echo $token->getClaim('iss'); // will print "http://example.com"
 echo $token->getClaim('uid'); // will print "1"
 ```
@@ -102,6 +104,8 @@ Hmac signatures are really simple to be used:
 use Lcobucci\JWT\Builder;
 use Lcobucci\JWT\Signer\Hmac\Sha256;
 
+$signer = new Sha256();
+
 $token = (new Builder())->setIssuer('http://example.com') // Configures the issuer (iss claim)
                         ->setAudience('http://example.org') // Configures the audience (aud claim)
                         ->setId('4f1g23a12aa', true) // Configures the id (jti claim), replicating as a header item
@@ -109,12 +113,12 @@ $token = (new Builder())->setIssuer('http://example.com') // Configures the issu
                         ->setNotBefore(time() + 60) // Configures the time that the token can be used (nbf claim)
                         ->setExpiration(time() + 3600) // Configures the expiration time of the token (nbf claim)
                         ->set('uid', 1) // Configures a new claim, called "uid"
-                        ->sign(new Sha256(), 'testing') // creates a signature using "testing" as key
+                        ->sign($signer, 'testing') // creates a signature using "testing" as key
                         ->getToken(); // Retrieves the generated token
 
 
-var_dump($token->verify('testing 1')); // false, because the key is different
-var_dump($token->verify('testing')); // true, because the key is the same
+var_dump($token->verify($signer, 'testing 1')); // false, because the key is different
+var_dump($token->verify($signer, 'testing')); // true, because the key is the same
 ```
 
 ### RSA and ECDSA
@@ -126,6 +130,8 @@ use Lcobucci\JWT\Builder;
 use Lcobucci\JWT\Signer\Keychain; // just to make our life simpler
 use Lcobucci\JWT\Signer\Rsa\Sha256; // you can use Lcobucci\JWT\Signer\Ecdsa\Sha256 if you're using ECDSA keys
 
+$signer = new Sha256();
+
 $keychain = new Keychain();
 
 $token = (new Builder())->setIssuer('http://example.com') // Configures the issuer (iss claim)
@@ -135,11 +141,11 @@ $token = (new Builder())->setIssuer('http://example.com') // Configures the issu
                         ->setNotBefore(time() + 60) // Configures the time that the token can be used (nbf claim)
                         ->setExpiration(time() + 3600) // Configures the expiration time of the token (nbf claim)
                         ->set('uid', 1) // Configures a new claim, called "uid"
-                        ->sign(new Sha256(), $keychain->getPrivateKey('file://{path to your private key}')) // creates a signature using your private key
+                        ->sign($signer,  $keychain->getPrivateKey('file://{path to your private key}')) // creates a signature using your private key
                         ->getToken(); // Retrieves the generated token
 
 
-var_dump($token->verify($keychain->getPublicKey('file://{path to your public key}')); // true when the public key was generated by the private one =)
+var_dump($token->verify($signer, $keychain->getPublicKey('file://{path to your public key}')); // true when the public key was generated by the private one =)
 ```
 
 **It's important to say that if you're using RSA keys you shouldn't invoke ECDSA signers (and vice-versa), otherwise ```sign()``` and ```verify()``` will raise an exception!**
diff --git a/composer.lock b/composer.lock
index 3237deb1..ede998bf 100644
--- a/composer.lock
+++ b/composer.lock
@@ -151,16 +151,16 @@
         },
         {
             "name": "phpmd/phpmd",
-            "version": "2.2.1",
+            "version": "2.2.2",
             "source": {
                 "type": "git",
                 "url": "https://github.com/phpmd/phpmd.git",
-                "reference": "58c4b00f924d301e8c5281f40cfa9a66f3df9eee"
+                "reference": "7dc4a6b5c07b119ab5da7960b56303fa6855eb84"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/phpmd/phpmd/zipball/58c4b00f924d301e8c5281f40cfa9a66f3df9eee",
-                "reference": "58c4b00f924d301e8c5281f40cfa9a66f3df9eee",
+                "url": "https://api.github.com/repos/phpmd/phpmd/zipball/7dc4a6b5c07b119ab5da7960b56303fa6855eb84",
+                "reference": "7dc4a6b5c07b119ab5da7960b56303fa6855eb84",
                 "shasum": ""
             },
             "require": {
@@ -209,25 +209,26 @@
                 "phpmd",
                 "pmd"
             ],
-            "time": "2015-03-02 10:26:50"
+            "time": "2015-03-26 07:47:05"
         },
         {
             "name": "phpspec/prophecy",
-            "version": "v1.3.1",
+            "version": "1.4.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/phpspec/prophecy.git",
-                "reference": "9ca52329bcdd1500de24427542577ebf3fc2f1c9"
+                "reference": "8724cd239f8ef4c046f55a3b18b4d91cc7f3e4c5"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/phpspec/prophecy/zipball/9ca52329bcdd1500de24427542577ebf3fc2f1c9",
-                "reference": "9ca52329bcdd1500de24427542577ebf3fc2f1c9",
+                "url": "https://api.github.com/repos/phpspec/prophecy/zipball/8724cd239f8ef4c046f55a3b18b4d91cc7f3e4c5",
+                "reference": "8724cd239f8ef4c046f55a3b18b4d91cc7f3e4c5",
                 "shasum": ""
             },
             "require": {
-                "doctrine/instantiator": "~1.0,>=1.0.2",
-                "phpdocumentor/reflection-docblock": "~2.0"
+                "doctrine/instantiator": "^1.0.2",
+                "phpdocumentor/reflection-docblock": "~2.0",
+                "sebastian/comparator": "~1.1"
             },
             "require-dev": {
                 "phpspec/phpspec": "~2.0"
@@ -235,7 +236,7 @@
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "1.2.x-dev"
+                    "dev-master": "1.4.x-dev"
                 }
             },
             "autoload": {
@@ -259,7 +260,7 @@
                 }
             ],
             "description": "Highly opinionated mocking framework for PHP 5.3+",
-            "homepage": "http://phpspec.org",
+            "homepage": "https://github.com/phpspec/prophecy",
             "keywords": [
                 "Double",
                 "Dummy",
@@ -268,7 +269,7 @@
                 "spy",
                 "stub"
             ],
-            "time": "2014-11-17 16:23:49"
+            "time": "2015-03-27 19:31:25"
         },
         {
             "name": "phpunit/php-code-coverage",
@@ -562,16 +563,16 @@
         },
         {
             "name": "phpunit/phpunit",
-            "version": "4.5.0",
+            "version": "4.5.1",
             "source": {
                 "type": "git",
                 "url": "https://github.com/sebastianbergmann/phpunit.git",
-                "reference": "5b578d3865a9128b9c209b011fda6539ec06e7a5"
+                "reference": "d6429b0995b24a2d9dfe5587ee3a7071c1161af4"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/sebastianbergmann/phpunit/zipball/5b578d3865a9128b9c209b011fda6539ec06e7a5",
-                "reference": "5b578d3865a9128b9c209b011fda6539ec06e7a5",
+                "url": "https://api.github.com/repos/sebastianbergmann/phpunit/zipball/d6429b0995b24a2d9dfe5587ee3a7071c1161af4",
+                "reference": "d6429b0995b24a2d9dfe5587ee3a7071c1161af4",
                 "shasum": ""
             },
             "require": {
@@ -581,8 +582,8 @@
                 "ext-reflection": "*",
                 "ext-spl": "*",
                 "php": ">=5.3.3",
-                "phpspec/prophecy": "~1.3.1",
-                "phpunit/php-code-coverage": "~2.0",
+                "phpspec/prophecy": "~1.3,>=1.3.1",
+                "phpunit/php-code-coverage": "~2.0,>=2.0.11",
                 "phpunit/php-file-iterator": "~1.3.2",
                 "phpunit/php-text-template": "~1.2",
                 "phpunit/php-timer": "~1.0.2",
@@ -630,7 +631,7 @@
                 "testing",
                 "xunit"
             ],
-            "time": "2015-02-05 15:51:19"
+            "time": "2015-03-29 09:24:05"
         },
         {
             "name": "phpunit/phpunit-mock-objects",
@@ -1134,23 +1135,26 @@
         },
         {
             "name": "symfony/config",
-            "version": "v2.6.4",
+            "version": "v2.6.5",
             "target-dir": "Symfony/Component/Config",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/Config.git",
-                "reference": "a9f781ba1221067d1f07c8cec0bc50f81b8d7408"
+                "reference": "7a47189c7667ca69bcaafd19ef8a8941db449a2c"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/Config/zipball/a9f781ba1221067d1f07c8cec0bc50f81b8d7408",
-                "reference": "a9f781ba1221067d1f07c8cec0bc50f81b8d7408",
+                "url": "https://api.github.com/repos/symfony/Config/zipball/7a47189c7667ca69bcaafd19ef8a8941db449a2c",
+                "reference": "7a47189c7667ca69bcaafd19ef8a8941db449a2c",
                 "shasum": ""
             },
             "require": {
                 "php": ">=5.3.3",
                 "symfony/filesystem": "~2.3"
             },
+            "require-dev": {
+                "symfony/phpunit-bridge": "~2.7"
+            },
             "type": "library",
             "extra": {
                 "branch-alias": {
@@ -1178,21 +1182,21 @@
             ],
             "description": "Symfony Config Component",
             "homepage": "http://symfony.com",
-            "time": "2015-01-21 20:57:55"
+            "time": "2015-03-12 10:28:44"
         },
         {
             "name": "symfony/dependency-injection",
-            "version": "v2.6.4",
+            "version": "v2.6.5",
             "target-dir": "Symfony/Component/DependencyInjection",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/DependencyInjection.git",
-                "reference": "42bbb43fab66292a1865dc9616c299904c3d4d14"
+                "reference": "a49245b2beebe332924561c30772b16e1d32f13a"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/DependencyInjection/zipball/42bbb43fab66292a1865dc9616c299904c3d4d14",
-                "reference": "42bbb43fab66292a1865dc9616c299904c3d4d14",
+                "url": "https://api.github.com/repos/symfony/DependencyInjection/zipball/a49245b2beebe332924561c30772b16e1d32f13a",
+                "reference": "a49245b2beebe332924561c30772b16e1d32f13a",
                 "shasum": ""
             },
             "require": {
@@ -1204,6 +1208,7 @@
             "require-dev": {
                 "symfony/config": "~2.2",
                 "symfony/expression-language": "~2.6",
+                "symfony/phpunit-bridge": "~2.7",
                 "symfony/yaml": "~2.1"
             },
             "suggest": {
@@ -1238,26 +1243,29 @@
             ],
             "description": "Symfony DependencyInjection Component",
             "homepage": "http://symfony.com",
-            "time": "2015-01-25 04:39:26"
+            "time": "2015-03-17 12:44:40"
         },
         {
             "name": "symfony/filesystem",
-            "version": "v2.6.4",
+            "version": "v2.6.5",
             "target-dir": "Symfony/Component/Filesystem",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/Filesystem.git",
-                "reference": "a1f566d1f92e142fa1593f4555d6d89e3044a9b7"
+                "reference": "fdc5f151bc2db066b51870d5bea3773d915ced0b"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/Filesystem/zipball/a1f566d1f92e142fa1593f4555d6d89e3044a9b7",
-                "reference": "a1f566d1f92e142fa1593f4555d6d89e3044a9b7",
+                "url": "https://api.github.com/repos/symfony/Filesystem/zipball/fdc5f151bc2db066b51870d5bea3773d915ced0b",
+                "reference": "fdc5f151bc2db066b51870d5bea3773d915ced0b",
                 "shasum": ""
             },
             "require": {
                 "php": ">=5.3.3"
             },
+            "require-dev": {
+                "symfony/phpunit-bridge": "~2.7"
+            },
             "type": "library",
             "extra": {
                 "branch-alias": {
@@ -1285,26 +1293,29 @@
             ],
             "description": "Symfony Filesystem Component",
             "homepage": "http://symfony.com",
-            "time": "2015-01-03 21:13:09"
+            "time": "2015-03-12 10:28:44"
         },
         {
             "name": "symfony/yaml",
-            "version": "v2.6.4",
+            "version": "v2.6.5",
             "target-dir": "Symfony/Component/Yaml",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/Yaml.git",
-                "reference": "60ed7751671113cf1ee7d7778e691642c2e9acd8"
+                "reference": "0cd8e72071e46e15fc072270ae39ea1b66b10a9d"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/Yaml/zipball/60ed7751671113cf1ee7d7778e691642c2e9acd8",
-                "reference": "60ed7751671113cf1ee7d7778e691642c2e9acd8",
+                "url": "https://api.github.com/repos/symfony/Yaml/zipball/0cd8e72071e46e15fc072270ae39ea1b66b10a9d",
+                "reference": "0cd8e72071e46e15fc072270ae39ea1b66b10a9d",
                 "shasum": ""
             },
             "require": {
                 "php": ">=5.3.3"
             },
+            "require-dev": {
+                "symfony/phpunit-bridge": "~2.7"
+            },
             "type": "library",
             "extra": {
                 "branch-alias": {
@@ -1332,7 +1343,7 @@
             ],
             "description": "Symfony Yaml Component",
             "homepage": "http://symfony.com",
-            "time": "2015-01-25 04:39:26"
+            "time": "2015-03-12 10:28:44"
         }
     ],
     "aliases": [],
diff --git a/src/Builder.php b/src/Builder.php
index c6b92687..c2b1e2a4 100644
--- a/src/Builder.php
+++ b/src/Builder.php
@@ -24,7 +24,7 @@ class Builder
      *
      * @var array
      */
-    private $header;
+    private $headers;
 
     /**
      * The token claim set
@@ -66,7 +66,7 @@ public function __construct(
     ) {
         $this->encoder = $encoder ?: new Encoder();
         $this->claimFactory = $claimFactory ?: new ClaimFactory();
-        $this->header = ['typ'=> 'JWT', 'alg' => 'none'];
+        $this->headers = ['typ'=> 'JWT', 'alg' => 'none'];
         $this->claims = [];
     }
 
@@ -175,7 +175,7 @@ protected function setRegisteredClaim($name, $value, $replicate)
         $this->set($name, $value);
 
         if ($replicate) {
-            $this->header[$name] = $this->claims[$name];
+            $this->headers[$name] = $this->claims[$name];
         }
 
         return $this;
@@ -212,7 +212,7 @@ public function set($name, $value)
      */
     public function sign(Signer $signer, $key)
     {
-        $signer->modifyHeader($this->header);
+        $signer->modifyHeader($this->headers);
 
         $this->signature = $signer->sign(
             $this->getToken()->getPayload(),
@@ -241,7 +241,7 @@ public function unsign()
      */
     public function getToken()
     {
-        $token = new Token($this->header, $this->claims, $this->signature);
+        $token = new Token($this->headers, $this->claims, $this->signature);
         $token->setEncoder($this->encoder);
 
         return $token;
diff --git a/src/Parser.php b/src/Parser.php
index ba54d4b2..03be11e7 100644
--- a/src/Parser.php
+++ b/src/Parser.php
@@ -11,7 +11,6 @@
 use Lcobucci\JWT\Claim\Factory as ClaimFactory;
 use Lcobucci\JWT\Parsing\Decoder;
 use Lcobucci\JWT\Parsing\Encoder;
-use Lcobucci\JWT\Signer\Factory as SignerFactory;
 
 /**
  * This class parses the JWT strings and convert them into tokens
@@ -35,13 +34,6 @@ class Parser
      */
     private $decoder;
 
-    /**
-     * The signer factory
-     *
-     * @var SignerFactory
-     */
-    private $signerFactory;
-
     /**
      * The claims factory
      *
@@ -54,18 +46,15 @@ class Parser
      *
      * @param Encoder $encoder
      * @param Decoder $decoder
-     * @param SignerFactory $signerFactory
      * @param ClaimFactory $claimFactory
      */
     public function __construct(
         Encoder $encoder = null,
         Decoder $decoder = null,
-        SignerFactory $signerFactory = null,
         ClaimFactory $claimFactory = null
     ) {
         $this->encoder = $encoder ?: new Encoder();
         $this->decoder = $decoder ?: new Decoder();
-        $this->signerFactory = $signerFactory ?: new SignerFactory();
         $this->claimFactory = $claimFactory ?: new ClaimFactory();
     }
 
@@ -141,7 +130,7 @@ protected function splitJwt($jwt)
      */
     protected function parseHeader($data)
     {
-        $header = $this->decoder->jsonDecode($this->decoder->base64UrlDecode($data));
+        $header = (array) $this->decoder->jsonDecode($this->decoder->base64UrlDecode($data));
 
         if (isset($header['enc'])) {
             throw new InvalidArgumentException('Encryption is not supported yet');
@@ -159,7 +148,7 @@ protected function parseHeader($data)
      */
     protected function parseClaims($data)
     {
-        $claims = $this->decoder->jsonDecode($this->decoder->base64UrlDecode($data));
+        $claims = (array) $this->decoder->jsonDecode($this->decoder->base64UrlDecode($data));
 
         foreach ($claims as $name => &$value) {
             $value = $this->claimFactory->create($name, $value);
@@ -184,6 +173,6 @@ protected function parseSignature(array $header, $data)
 
         $hash = $this->decoder->base64UrlDecode($data);
 
-        return new Signature($this->signerFactory->create($header['alg']), $hash);
+        return new Signature($hash);
     }
 }
diff --git a/src/Parsing/Decoder.php b/src/Parsing/Decoder.php
index 854ac9ee..86336b08 100644
--- a/src/Parsing/Decoder.php
+++ b/src/Parsing/Decoder.php
@@ -30,16 +30,12 @@ class Decoder
      */
     public function jsonDecode($json)
     {
-        $data = json_decode($json, true);
+        $data = json_decode($json);
 
         if (json_last_error() != JSON_ERROR_NONE) {
             throw new RuntimeException('Error while decoding to JSON: ' . json_last_error_msg());
         }
 
-        if (!is_array($data)) {
-            throw new RuntimeException('The decoded data must be an array');
-        }
-
         return $data;
     }
 
diff --git a/src/Signature.php b/src/Signature.php
index e5efb71c..42f2b22a 100644
--- a/src/Signature.php
+++ b/src/Signature.php
@@ -15,13 +15,6 @@
  */
 class Signature
 {
-    /**
-     * The signer that created this signature
-     *
-     * @var Signer
-     */
-    protected $signer;
-
     /**
      * The resultant hash
      *
@@ -32,12 +25,10 @@ class Signature
     /**
      * Initializes the object
      *
-     * @param Signer $signer
      * @param string $hash
      */
-    public function __construct(Signer $signer, $hash)
+    public function __construct($hash)
     {
-        $this->signer = $signer;
         $this->hash = $hash;
     }
 
@@ -45,14 +36,15 @@ public function __construct(Signer $signer, $hash)
      * Verifies if the current hash matches with with the result of the creation of
      * a new signature with given data
      *
+     * @param Signer $signer
      * @param string $payload
      * @param string $key
      *
      * @return boolean
      */
-    public function verify($payload, $key)
+    public function verify(Signer $signer, $payload, $key)
     {
-        return $this->signer->verify($this->hash, $payload, $key);
+        return $signer->verify($this->hash, $payload, $key);
     }
 
     /**
diff --git a/src/Signer/BaseSigner.php b/src/Signer/BaseSigner.php
index 68507db4..a7faef3f 100644
--- a/src/Signer/BaseSigner.php
+++ b/src/Signer/BaseSigner.php
@@ -32,7 +32,7 @@ public function modifyHeader(array &$headers)
      */
     public function sign($payload, $key)
     {
-        return new Signature($this, $this->createHash($payload, $key));
+        return new Signature($this->createHash($payload, $key));
     }
 
     /**
diff --git a/src/Signer/Factory.php b/src/Signer/Factory.php
deleted file mode 100644
index 84fa6a63..00000000
--- a/src/Signer/Factory.php
+++ /dev/null
@@ -1,149 +0,0 @@
-<?php
-/**
- * This file is part of Lcobucci\JWT, a simple library to handle JWT and JWS
- *
- * @license http://opensource.org/licenses/BSD-3-Clause BSD-3-Clause
- */
-
-namespace Lcobucci\JWT\Signer;
-
-use InvalidArgumentException;
-use Lcobucci\JWT\Signer;
-use Lcobucci\JWT\Signer\Ecdsa\Sha256 as EcdsaSha256;
-use Lcobucci\JWT\Signer\Ecdsa\Sha384 as EcdsaSha384;
-use Lcobucci\JWT\Signer\Ecdsa\Sha512 as EcdsaSha512;
-use Lcobucci\JWT\Signer\Hmac\Sha256 as HmacSha256;
-use Lcobucci\JWT\Signer\Hmac\Sha384 as HmacSha384;
-use Lcobucci\JWT\Signer\Hmac\Sha512 as HmacSha512;
-use Lcobucci\JWT\Signer\Rsa\Sha256 as RsaSha256;
-use Lcobucci\JWT\Signer\Rsa\Sha384 as RsaSha384;
-use Lcobucci\JWT\Signer\Rsa\Sha512 as RsaSha512;
-
-/**
- * Factory that returns instance of signers
- *
- * @author Luís Otávio Cobucci Oblonczyk <lcobucci@gmail.com>
- * @since 0.1.0
- */
-class Factory
-{
-    /**
-     * The list of signers callbacks
-     *
-     * @var array
-     */
-    private $callbacks;
-
-    /**
-     * Initializes the factory, registering the default callbacks
-     *
-     * @param array $callbacks
-     */
-    public function __construct(array $callbacks = [])
-    {
-        $this->callbacks = array_merge(
-            [
-                'HS256' => [$this, 'createHmacSha256'],
-                'HS384' => [$this, 'createHmacSha384'],
-                'HS512' => [$this, 'createHmacSha512'],
-                'ES256' => [$this, 'createEcdsaSha256'],
-                'ES384' => [$this, 'createEcdsaSha384'],
-                'ES512' => [$this, 'createEcdsaSha512'],
-                'RS256' => [$this, 'createRsaSha256'],
-                'RS384' => [$this, 'createRsaSha384'],
-                'RS512' => [$this, 'createRsaSha512']
-            ],
-            $callbacks
-        );
-    }
-
-    /**
-     * Retrieves a signer instance
-     *
-     * @param string $id
-     *
-     * @return Signer
-     *
-     * @throws InvalidArgumentException When signer is not implemented or invalid
-     */
-    public function create($id)
-    {
-        if (isset($this->callbacks[$id])) {
-            return call_user_func($this->callbacks[$id]);
-        }
-
-        throw new InvalidArgumentException('Invalid signer');
-    }
-
-    /**
-     * @return HmacSha256
-     */
-    private function createHmacSha256()
-    {
-        return new HmacSha256();
-    }
-
-    /**
-     * @return HmacSha384
-     */
-    private function createHmacSha384()
-    {
-        return new HmacSha384();
-    }
-
-    /**
-     * @return HmacSha512
-     */
-    private function createHmacSha512()
-    {
-        return new HmacSha512();
-    }
-
-    /**
-     * @return RsaSha256
-     */
-    private function createRsaSha256()
-    {
-        return new RsaSha256();
-    }
-
-    /**
-     * @return RsaSha384
-     */
-    private function createRsaSha384()
-    {
-        return new RsaSha384();
-    }
-
-    /**
-     * @return RsaSha512
-     */
-    private function createRsaSha512()
-    {
-        return new RsaSha512();
-    }
-
-    /**
-     * @return EcdsaSha256
-     */
-    private function createEcdsaSha256()
-    {
-        return new EcdsaSha256();
-    }
-
-    /**
-     * @return EcdsaSha384
-     */
-    private function createEcdsaSha384()
-    {
-        return new EcdsaSha384();
-    }
-
-    /**
-     * @return EcdsaSha512
-     */
-    private function createEcdsaSha512()
-    {
-        return new EcdsaSha512();
-    }
-}
diff --git a/src/Token.php b/src/Token.php
index 4236d3fa..fe791a31 100644
--- a/src/Token.php
+++ b/src/Token.php
@@ -22,11 +22,11 @@
 class Token
 {
     /**
-     * The token header
+     * The token headers
      *
      * @var array
      */
-    private $header;
+    private $headers;
 
     /**
      * The token claim set
@@ -52,16 +52,16 @@ class Token
     /**
      * Initializes the object
      *
-     * @param array $header
+     * @param array $headers
      * @param array $claims
      * @param Signature $signature
      */
     public function __construct(
-        array $header = ['alg' => 'none'],
+        array $headers = ['alg' => 'none'],
         array $claims = [],
         Signature $signature = null
     ) {
-        $this->header = $header;
+        $this->headers = $headers;
         $this->claims = $claims;
         $this->signature = $signature;
     }
@@ -77,13 +77,37 @@ public function setEncoder(Encoder $encoder)
     }
 
     /**
-     * Returns the token header
+     * Returns the token headers
      *
      * @return array
      */
-    public function getHeader()
+    public function getHeaders()
     {
-        return $this->header;
+        return $this->headers;
+    }
+
+    /**
+     * Returns the value of a token header
+     *
+     * @param string $name
+     *
+     * @return mixed
+     *
+     * @throws OutOfBoundsException
+     */
+    public function getHeader($name)
+    {
+        if (!isset($this->headers[$name])) {
+            throw new OutOfBoundsException('Requested header is not configured');
+        }
+
+        $header = $this->headers[$name];
+
+        if ($header instanceof Claim) {
+            return $header->getValue();
+        }
+
+        return $header;
     }
 
     /**
@@ -114,32 +138,27 @@ public function getClaim($name)
         return $this->claims[$name]->getValue();
     }
 
-    /**
-     * Returns the token signature
-     *
-     * @return Signature
-     */
-    public function getSignature()
-    {
-        return $this->signature;
-    }
-
     /**
      * Verify if the key matches with the one that created the signature
      *
+     * @param Signer $signer
      * @param string $key
      *
      * @return boolean
      *
      * @throws BadMethodCallException When token is not signed
      */
-    public function verify($key)
+    public function verify(Signer $signer, $key)
     {
         if ($this->signature === null) {
             throw new BadMethodCallException('This token is not signed');
         }
 
-        return $this->signature->verify($this->getPayload(), $key);
+        if ($this->headers['alg'] !== $signer->getAlgorithmId()) {
+            return false;
+        }
+
+        return $this->signature->verify($signer, $this->getPayload(), $key);
     }
 
     /**
@@ -189,7 +208,7 @@ public function getPayload()
 
         return sprintf(
             '%s.%s',
-            $this->encoder->base64UrlEncode($this->encoder->jsonEncode($this->header)),
+            $this->encoder->base64UrlEncode($this->encoder->jsonEncode($this->headers)),
             $this->encoder->base64UrlEncode($this->encoder->jsonEncode($this->claims))
         );
     }
diff --git a/test/BuilderTest.php b/test/BuilderTest.php
index c3c94137..cbcb3a8a 100644
--- a/test/BuilderTest.php
+++ b/test/BuilderTest.php
@@ -62,7 +62,7 @@ public function constructMustInitializeTheAttributes()
     {
         $builder = $this->createBuilder();
 
-        $this->assertAttributeEquals(['alg' => 'none', 'typ' => 'JWT'], 'header', $builder);
+        $this->assertAttributeEquals(['alg' => 'none', 'typ' => 'JWT'], 'headers', $builder);
         $this->assertAttributeEquals([], 'claims', $builder);
         $this->assertAttributeEquals(null, 'signature', $builder);
         $this->assertAttributeSame($this->encoder, 'encoder', $builder);
@@ -83,7 +83,7 @@ public function setAudienceMustChangeTheAudClaim()
         $builder = $this->createBuilder();
         $builder->setAudience('test');
 
-        $this->assertAttributeEquals(['alg' => 'none', 'typ' => 'JWT'], 'header', $builder);
+        $this->assertAttributeEquals(['alg' => 'none', 'typ' => 'JWT'], 'headers', $builder);
         $this->assertAttributeEquals(['aud' => $this->defaultClaim], 'claims', $builder);
     }
 
@@ -105,7 +105,7 @@ public function setAudienceCanReplicateItemOnHeader()
 
         $this->assertAttributeEquals(
             ['alg' => 'none', 'typ' => 'JWT', 'aud' => $this->defaultClaim],
-            'header',
+            'headers',
             $builder
         );
     }
@@ -140,7 +140,7 @@ public function setExpirationMustChangeTheExpClaim()
         $builder = $this->createBuilder();
         $builder->setExpiration('2');
 
-        $this->assertAttributeEquals(['alg' => 'none', 'typ' => 'JWT'], 'header', $builder);
+        $this->assertAttributeEquals(['alg' => 'none', 'typ' => 'JWT'], 'headers', $builder);
         $this->assertAttributeEquals(['exp' => $this->defaultClaim], 'claims', $builder);
     }
 
@@ -162,7 +162,7 @@ public function setExpirationCanReplicateItemOnHeader()
 
         $this->assertAttributeEquals(
             ['alg' => 'none', 'typ' => 'JWT', 'exp' => $this->defaultClaim],
-            'header',
+            'headers',
             $builder
         );
     }
@@ -197,7 +197,7 @@ public function setIdMustChangeTheJtiClaim()
         $builder = $this->createBuilder();
         $builder->setId('2');
 
-        $this->assertAttributeEquals(['alg' => 'none', 'typ' => 'JWT'], 'header', $builder);
+        $this->assertAttributeEquals(['alg' => 'none', 'typ' => 'JWT'], 'headers', $builder);
         $this->assertAttributeEquals(['jti' => $this->defaultClaim], 'claims', $builder);
     }
 
@@ -219,7 +219,7 @@ public function setIdCanReplicateItemOnHeader()
 
         $this->assertAttributeEquals(
             ['alg' => 'none', 'typ' => 'JWT', 'jti' => $this->defaultClaim],
-            'header',
+            'headers',
             $builder
         );
     }
@@ -254,7 +254,7 @@ public function setIssuedAtMustChangeTheIatClaim()
         $builder = $this->createBuilder();
         $builder->setIssuedAt('2');
 
-        $this->assertAttributeEquals(['alg' => 'none', 'typ' => 'JWT'], 'header', $builder);
+        $this->assertAttributeEquals(['alg' => 'none', 'typ' => 'JWT'], 'headers', $builder);
         $this->assertAttributeEquals(['iat' => $this->defaultClaim], 'claims', $builder);
     }
 
@@ -276,7 +276,7 @@ public function setIssuedAtCanReplicateItemOnHeader()
 
         $this->assertAttributeEquals(
             ['alg' => 'none', 'typ' => 'JWT', 'iat' => $this->defaultClaim],
-            'header',
+            'headers',
             $builder
         );
     }
@@ -311,7 +311,7 @@ public function setIssuerMustChangeTheIssClaim()
         $builder = $this->createBuilder();
         $builder->setIssuer('2');
 
-        $this->assertAttributeEquals(['alg' => 'none', 'typ' => 'JWT'], 'header', $builder);
+        $this->assertAttributeEquals(['alg' => 'none', 'typ' => 'JWT'], 'headers', $builder);
         $this->assertAttributeEquals(['iss' => $this->defaultClaim], 'claims', $builder);
     }
 
@@ -333,7 +333,7 @@ public function setIssuerCanReplicateItemOnHeader()
 
         $this->assertAttributeEquals(
             ['alg' => 'none', 'typ' => 'JWT', 'iss' => $this->defaultClaim],
-            'header',
+            'headers',
             $builder
         );
     }
@@ -368,7 +368,7 @@ public function setNotBeforeMustChangeTheNbfClaim()
         $builder = $this->createBuilder();
         $builder->setNotBefore('2');
 
-        $this->assertAttributeEquals(['alg' => 'none', 'typ' => 'JWT'], 'header', $builder);
+        $this->assertAttributeEquals(['alg' => 'none', 'typ' => 'JWT'], 'headers', $builder);
         $this->assertAttributeEquals(['nbf' => $this->defaultClaim], 'claims', $builder);
     }
 
@@ -390,7 +390,7 @@ public function setNotBeforeCanReplicateItemOnHeader()
 
         $this->assertAttributeEquals(
             ['alg' => 'none', 'typ' => 'JWT', 'nbf' => $this->defaultClaim],
-            'header',
+            'headers',
             $builder
         );
     }
@@ -425,7 +425,7 @@ public function setSubjectMustChangeTheSubClaim()
         $builder = $this->createBuilder();
         $builder->setSubject('2');
 
-        $this->assertAttributeEquals(['alg' => 'none', 'typ' => 'JWT'], 'header', $builder);
+        $this->assertAttributeEquals(['alg' => 'none', 'typ' => 'JWT'], 'headers', $builder);
         $this->assertAttributeEquals(['sub' => $this->defaultClaim], 'claims', $builder);
     }
 
@@ -447,7 +447,7 @@ public function setSubjectCanReplicateItemOnHeader()
 
         $this->assertAttributeEquals(
             ['alg' => 'none', 'typ' => 'JWT', 'sub' => $this->defaultClaim],
-            'header',
+            'headers',
             $builder
         );
     }
@@ -504,9 +504,8 @@ public function setMustKeepAFluentInterface()
      * @uses Lcobucci\JWT\Builder::set
      * @uses Lcobucci\JWT\Token::__construct
      * @uses Lcobucci\JWT\Token::setEncoder
-     * @uses Lcobucci\JWT\Token::getHeader
+     * @uses Lcobucci\JWT\Token::getHeaders
      * @uses Lcobucci\JWT\Token::getClaims
-     * @uses Lcobucci\JWT\Token::getSignature
      *
      * @covers Lcobucci\JWT\Builder::getToken
      */
@@ -515,9 +514,12 @@ public function getTokenMustReturnANewTokenWithCurrentConfiguration()
         $builder = $this->createBuilder();
         $token = $builder->set('test', 123)->getToken();
 
-        $this->assertAttributeEquals($token->getHeader(), 'header', $builder);
+        $signatureAttr = new \ReflectionProperty($token, 'signature');
+        $signatureAttr->setAccessible(true);
+
+        $this->assertAttributeEquals($token->getHeaders(), 'headers', $builder);
         $this->assertAttributeEquals($token->getClaims(), 'claims', $builder);
-        $this->assertAttributeSame($token->getSignature(), 'signature', $builder);
+        $this->assertAttributeSame($signatureAttr->getValue($token), 'signature', $builder);
     }
 
     /**
diff --git a/test/FunctionalTests/EcdsaTokenTest.php b/test/FunctionalTests/EcdsaTokenTest.php
index de92689d..739b9155 100644
--- a/test/FunctionalTests/EcdsaTokenTest.php
+++ b/test/FunctionalTests/EcdsaTokenTest.php
@@ -13,6 +13,7 @@
 use Lcobucci\JWT\Signature;
 use Lcobucci\JWT\Signer\Ecdsa\Sha256;
 use Lcobucci\JWT\EcdsaKeys;
+use Lcobucci\JWT\Signer\Ecdsa\Sha512;
 
 /**
  * @author Luís Otávio Cobucci Oblonczyk <lcobucci@gmail.com>
@@ -22,6 +23,19 @@ class EcdsaTokenTest extends \PHPUnit_Framework_TestCase
 {
     use EcdsaKeys;
 
+    /**
+     * @var Sha256
+     */
+    private $signer;
+
+    /**
+     * @before
+     */
+    public function createSigner()
+    {
+        $this->signer = new Sha256();
+    }
+
     /**
      * @test
      *
@@ -38,13 +52,13 @@ class EcdsaTokenTest extends \PHPUnit_Framework_TestCase
      */
     public function builderCanGenerateAToken()
     {
-        $user = ['name' => 'testing', 'email' => 'testing@abc.com'];
+        $user = (object) ['name' => 'testing', 'email' => 'testing@abc.com'];
 
         $token = (new Builder())->setId(1)
                               ->setAudience('http://client.abc.com')
                               ->setIssuer('http://api.abc.com')
                               ->set('user', $user)
-                              ->sign(new Sha256(), $this->privateEcdsa())
+                              ->sign($this->signer, $this->privateEcdsa())
                               ->getToken();
 
         $this->assertAttributeInstanceOf(Signature::class, 'signature', $token);
@@ -68,13 +82,13 @@ public function builderCanGenerateAToken()
      * @covers Lcobucci\JWT\Claim\Basic
      * @covers Lcobucci\JWT\Parsing\Encoder
      * @covers Lcobucci\JWT\Parsing\Decoder
-     * @covers Lcobucci\JWT\Signer\Factory
      */
     public function parserCanReadAToken(Token $generated)
     {
         $read = (new Parser())->parse((string) $generated);
 
         $this->assertEquals($generated, $read);
+        $this->assertEquals('testing', $read->getClaim('user')->name);
     }
 
     /**
@@ -89,14 +103,35 @@ public function parserCanReadAToken(Token $generated)
      * @covers Lcobucci\JWT\Parsing\Encoder
      * @covers Lcobucci\JWT\Claim\Factory
      * @covers Lcobucci\JWT\Claim\Basic
-     * @covers Lcobucci\JWT\Signer\Factory
      * @covers Lcobucci\JWT\Signer\OpenSSL
      * @covers Lcobucci\JWT\Signer\Ecdsa
      * @covers Lcobucci\JWT\Signer\Ecdsa\Sha256
      */
     public function verifyShouldReturnFalseWhenKeyIsNotRight(Token $token)
     {
-        $this->assertFalse($token->verify($this->otherPublicEcdsa()));
+        $this->assertFalse($token->verify($this->signer, $this->otherPublicEcdsa()));
+    }
+
+    /**
+     * @test
+     *
+     * @depends builderCanGenerateAToken
+     *
+     * @covers Lcobucci\JWT\Builder
+     * @covers Lcobucci\JWT\Parser
+     * @covers Lcobucci\JWT\Token
+     * @covers Lcobucci\JWT\Signature
+     * @covers Lcobucci\JWT\Parsing\Encoder
+     * @covers Lcobucci\JWT\Claim\Factory
+     * @covers Lcobucci\JWT\Claim\Basic
+     * @covers Lcobucci\JWT\Signer\OpenSSL
+     * @covers Lcobucci\JWT\Signer\Ecdsa
+     * @covers Lcobucci\JWT\Signer\Ecdsa\Sha256
+     * @covers Lcobucci\JWT\Signer\Ecdsa\Sha512
+     */
+    public function verifyShouldReturnFalseWhenAlgorithmIsDifferent(Token $token)
+    {
+        $this->assertFalse($token->verify(new Sha512(), $this->publicEcdsa()));
     }
 
     /**
@@ -111,13 +146,12 @@ public function verifyShouldReturnFalseWhenKeyIsNotRight(Token $token)
      * @covers Lcobucci\JWT\Parsing\Encoder
      * @covers Lcobucci\JWT\Claim\Factory
      * @covers Lcobucci\JWT\Claim\Basic
-     * @covers Lcobucci\JWT\Signer\Factory
      * @covers Lcobucci\JWT\Signer\OpenSSL
      * @covers Lcobucci\JWT\Signer\Ecdsa
      * @covers Lcobucci\JWT\Signer\Ecdsa\Sha256
      */
     public function verifyShouldReturnTrueWhenKeyIsRight(Token $token)
     {
-        $this->assertTrue($token->verify($this->publicEcdsa()));
+        $this->assertTrue($token->verify($this->signer, $this->publicEcdsa()));
     }
 }
diff --git a/test/FunctionalTests/HmacTokenTest.php b/test/FunctionalTests/HmacTokenTest.php
index 18047c09..81af4d3f 100644
--- a/test/FunctionalTests/HmacTokenTest.php
+++ b/test/FunctionalTests/HmacTokenTest.php
@@ -12,6 +12,7 @@
 use Lcobucci\JWT\Token;
 use Lcobucci\JWT\Signature;
 use Lcobucci\JWT\Signer\Hmac\Sha256;
+use Lcobucci\JWT\Signer\Hmac\Sha512;
 
 /**
  * @author Luís Otávio Cobucci Oblonczyk <lcobucci@gmail.com>
@@ -19,6 +20,19 @@
  */
 class HmacTokenTest extends \PHPUnit_Framework_TestCase
 {
+    /**
+     * @var Sha256
+     */
+    private $signer;
+
+    /**
+     * @before
+     */
+    public function createSigner()
+    {
+        $this->signer = new Sha256();
+    }
+
     /**
      * @test
      *
@@ -34,13 +48,13 @@ class HmacTokenTest extends \PHPUnit_Framework_TestCase
      */
     public function builderCanGenerateAToken()
     {
-        $user = ['name' => 'testing', 'email' => 'testing@abc.com'];
+        $user = (object) ['name' => 'testing', 'email' => 'testing@abc.com'];
 
         $token = (new Builder())->setId(1)
                               ->setAudience('http://client.abc.com')
                               ->setIssuer('http://api.abc.com')
                               ->set('user', $user)
-                              ->sign(new Sha256(), 'testing')
+                              ->sign($this->signer, 'testing')
                               ->getToken();
 
         $this->assertAttributeInstanceOf(Signature::class, 'signature', $token);
@@ -64,13 +78,13 @@ public function builderCanGenerateAToken()
      * @covers Lcobucci\JWT\Claim\Basic
      * @covers Lcobucci\JWT\Parsing\Encoder
      * @covers Lcobucci\JWT\Parsing\Decoder
-     * @covers Lcobucci\JWT\Signer\Factory
      */
     public function parserCanReadAToken(Token $generated)
     {
         $read = (new Parser())->parse((string) $generated);
 
         $this->assertEquals($generated, $read);
+        $this->assertEquals('testing', $read->getClaim('user')->name);
     }
 
     /**
@@ -85,13 +99,34 @@ public function parserCanReadAToken(Token $generated)
      * @covers Lcobucci\JWT\Parsing\Encoder
      * @covers Lcobucci\JWT\Claim\Factory
      * @covers Lcobucci\JWT\Claim\Basic
-     * @covers Lcobucci\JWT\Signer\Factory
      * @covers Lcobucci\JWT\Signer\Hmac
      * @covers Lcobucci\JWT\Signer\Hmac\Sha256
      */
     public function verifyShouldReturnFalseWhenKeyIsNotRight(Token $token)
     {
-        $this->assertFalse($token->verify('testing1'));
+        $this->assertFalse($token->verify($this->signer, 'testing1'));
+    }
+
+    /**
+     * @test
+     *
+     * @depends builderCanGenerateAToken
+     *
+     * @covers Lcobucci\JWT\Builder
+     * @covers Lcobucci\JWT\Parser
+     * @covers Lcobucci\JWT\Token
+     * @covers Lcobucci\JWT\Signature
+     * @covers Lcobucci\JWT\Parsing\Encoder
+     * @covers Lcobucci\JWT\Claim\Factory
+     * @covers Lcobucci\JWT\Claim\Basic
+     * @covers Lcobucci\JWT\Signer\OpenSSL
+     * @covers Lcobucci\JWT\Signer\Hmac
+     * @covers Lcobucci\JWT\Signer\Hmac\Sha256
+     * @covers Lcobucci\JWT\Signer\Hmac\Sha512
+     */
+    public function verifyShouldReturnFalseWhenAlgorithmIsDifferent(Token $token)
+    {
+        $this->assertFalse($token->verify(new Sha512(), 'testing'));
     }
 
     /**
@@ -106,12 +141,11 @@ public function verifyShouldReturnFalseWhenKeyIsNotRight(Token $token)
      * @covers Lcobucci\JWT\Parsing\Encoder
      * @covers Lcobucci\JWT\Claim\Factory
      * @covers Lcobucci\JWT\Claim\Basic
-     * @covers Lcobucci\JWT\Signer\Factory
      * @covers Lcobucci\JWT\Signer\Hmac
      * @covers Lcobucci\JWT\Signer\Hmac\Sha256
      */
     public function verifyShouldReturnTrueWhenKeyIsRight(Token $token)
     {
-        $this->assertTrue($token->verify('testing'));
+        $this->assertTrue($token->verify($this->signer, 'testing'));
     }
 }
diff --git a/test/FunctionalTests/RsaTokenTest.php b/test/FunctionalTests/RsaTokenTest.php
index 37b8d702..b19ef53a 100644
--- a/test/FunctionalTests/RsaTokenTest.php
+++ b/test/FunctionalTests/RsaTokenTest.php
@@ -13,6 +13,7 @@
 use Lcobucci\JWT\Signature;
 use Lcobucci\JWT\Signer\Rsa\Sha256;
 use Lcobucci\JWT\RsaKeys;
+use Lcobucci\JWT\Signer\Rsa\Sha512;
 
 /**
  * @author Luís Otávio Cobucci Oblonczyk <lcobucci@gmail.com>
@@ -22,6 +23,19 @@ class RsaTokenTest extends \PHPUnit_Framework_TestCase
 {
     use RsaKeys;
 
+    /**
+     * @var Sha256
+     */
+    private $signer;
+
+    /**
+     * @before
+     */
+    public function createSigner()
+    {
+        $this->signer = new Sha256();
+    }
+
     /**
      * @test
      *
@@ -38,13 +52,13 @@ class RsaTokenTest extends \PHPUnit_Framework_TestCase
      */
     public function builderCanGenerateAToken()
     {
-        $user = ['name' => 'testing', 'email' => 'testing@abc.com'];
+        $user = (object) ['name' => 'testing', 'email' => 'testing@abc.com'];
 
         $token = (new Builder())->setId(1)
                               ->setAudience('http://client.abc.com')
                               ->setIssuer('http://api.abc.com')
                               ->set('user', $user)
-                              ->sign(new Sha256(), $this->privateRsa())
+                              ->sign($this->signer, $this->privateRsa())
                               ->getToken();
 
         $this->assertAttributeInstanceOf(Signature::class, 'signature', $token);
@@ -68,13 +82,13 @@ public function builderCanGenerateAToken()
      * @covers Lcobucci\JWT\Claim\Basic
      * @covers Lcobucci\JWT\Parsing\Encoder
      * @covers Lcobucci\JWT\Parsing\Decoder
-     * @covers Lcobucci\JWT\Signer\Factory
      */
     public function parserCanReadAToken(Token $generated)
     {
         $read = (new Parser())->parse((string) $generated);
 
         $this->assertEquals($generated, $read);
+        $this->assertEquals('testing', $read->getClaim('user')->name);
     }
 
     /**
@@ -89,14 +103,35 @@ public function parserCanReadAToken(Token $generated)
      * @covers Lcobucci\JWT\Parsing\Encoder
      * @covers Lcobucci\JWT\Claim\Factory
      * @covers Lcobucci\JWT\Claim\Basic
-     * @covers Lcobucci\JWT\Signer\Factory
      * @covers Lcobucci\JWT\Signer\OpenSSL
      * @covers Lcobucci\JWT\Signer\Rsa
      * @covers Lcobucci\JWT\Signer\Rsa\Sha256
      */
     public function verifyShouldReturnFalseWhenKeyIsNotRight(Token $token)
     {
-        $this->assertFalse($token->verify($this->encryptedPublicRsa()));
+        $this->assertFalse($token->verify($this->signer, $this->encryptedPublicRsa()));
+    }
+
+    /**
+     * @test
+     *
+     * @depends builderCanGenerateAToken
+     *
+     * @covers Lcobucci\JWT\Builder
+     * @covers Lcobucci\JWT\Parser
+     * @covers Lcobucci\JWT\Token
+     * @covers Lcobucci\JWT\Signature
+     * @covers Lcobucci\JWT\Parsing\Encoder
+     * @covers Lcobucci\JWT\Claim\Factory
+     * @covers Lcobucci\JWT\Claim\Basic
+     * @covers Lcobucci\JWT\Signer\OpenSSL
+     * @covers Lcobucci\JWT\Signer\Rsa
+     * @covers Lcobucci\JWT\Signer\Rsa\Sha256
+     * @covers Lcobucci\JWT\Signer\Rsa\Sha512
+     */
+    public function verifyShouldReturnFalseWhenAlgorithmIsDifferent(Token $token)
+    {
+        $this->assertFalse($token->verify(new Sha512(), $this->publicRsa()));
     }
 
     /**
@@ -111,13 +146,12 @@ public function verifyShouldReturnFalseWhenKeyIsNotRight(Token $token)
      * @covers Lcobucci\JWT\Parsing\Encoder
      * @covers Lcobucci\JWT\Claim\Factory
      * @covers Lcobucci\JWT\Claim\Basic
-     * @covers Lcobucci\JWT\Signer\Factory
      * @covers Lcobucci\JWT\Signer\OpenSSL
      * @covers Lcobucci\JWT\Signer\Rsa
      * @covers Lcobucci\JWT\Signer\Rsa\Sha256
      */
     public function verifyShouldReturnTrueWhenKeyIsRight(Token $token)
     {
-        $this->assertTrue($token->verify($this->publicRsa()));
+        $this->assertTrue($token->verify($this->signer, $this->publicRsa()));
     }
 }
diff --git a/test/FunctionalTests/UnsignedTokenTest.php b/test/FunctionalTests/UnsignedTokenTest.php
index e3bda3a3..a6280b88 100644
--- a/test/FunctionalTests/UnsignedTokenTest.php
+++ b/test/FunctionalTests/UnsignedTokenTest.php
@@ -30,7 +30,7 @@ class UnsignedTokenTest extends \PHPUnit_Framework_TestCase
      */
     public function builderCanGenerateAToken()
     {
-        $user = ['name' => 'testing', 'email' => 'testing@abc.com'];
+        $user = (object) ['name' => 'testing', 'email' => 'testing@abc.com'];
 
         $token = (new Builder())->setId(1)
                               ->setAudience('http://client.abc.com')
@@ -60,13 +60,13 @@ public function builderCanGenerateAToken()
      * @covers Lcobucci\JWT\Claim\Basic
      * @covers Lcobucci\JWT\Parsing\Encoder
      * @covers Lcobucci\JWT\Parsing\Decoder
-     * @covers Lcobucci\JWT\Signer\Factory
      */
     public function parserCanReadAToken(Token $generated)
     {
         $read = (new Parser())->parse((string) $generated);
 
         $this->assertEquals($generated, $read);
+        $this->assertEquals('testing', $read->getClaim('user')->name);
     }
 
     /**
@@ -84,9 +84,8 @@ public function parserCanReadAToken(Token $generated)
      * @covers Lcobucci\JWT\Claim\GreaterOrEqualsTo
      * @covers Lcobucci\JWT\Parsing\Encoder
      * @covers Lcobucci\JWT\Parsing\Decoder
-     * @covers Lcobucci\JWT\Signer\Factory
      */
-    public function tokenValidationShouldReturnWhenEverythingIsFile(Token $generated)
+    public function tokenValidationShouldReturnWhenEverythingIsFine(Token $generated)
     {
         $data = new ValidationData(self::CURRENT_TIME - 10);
         $data->setAudience('http://client.abc.com');
@@ -112,7 +111,6 @@ public function tokenValidationShouldReturnWhenEverythingIsFile(Token $generated
      * @covers Lcobucci\JWT\Claim\GreaterOrEqualsTo
      * @covers Lcobucci\JWT\Parsing\Encoder
      * @covers Lcobucci\JWT\Parsing\Decoder
-     * @covers Lcobucci\JWT\Signer\Factory
      */
     public function tokenValidationShouldReturnFalseWhenExpectedDataDontMatch(ValidationData $data, Token $generated)
     {
diff --git a/test/ParserTest.php b/test/ParserTest.php
index 90c04a1b..2c315c36 100644
--- a/test/ParserTest.php
+++ b/test/ParserTest.php
@@ -10,7 +10,6 @@
 use Lcobucci\JWT\Claim\Factory as ClaimFactory;
 use Lcobucci\JWT\Parsing\Decoder;
 use Lcobucci\JWT\Parsing\Encoder;
-use Lcobucci\JWT\Signer\Factory as SignerFactory;
 use RuntimeException;
 
 /**
@@ -29,11 +28,6 @@ class ParserTest extends \PHPUnit_Framework_TestCase
      */
     protected $decoder;
 
-    /**
-     * @var SignerFactory|\PHPUnit_Framework_MockObject_MockObject
-     */
-    protected $signerFactory;
-
     /**
      * @var ClaimFactory|\PHPUnit_Framework_MockObject_MockObject
      */
@@ -51,7 +45,6 @@ protected function setUp()
     {
         $this->encoder = $this->getMock(Encoder::class);
         $this->decoder = $this->getMock(Decoder::class);
-        $this->signerFactory = $this->getMock(SignerFactory::class, [], [], '', false);
         $this->claimFactory = $this->getMock(ClaimFactory::class, [], [], '', false);
         $this->defaultClaim = $this->getMock(Claim::class);
 
@@ -68,7 +61,6 @@ private function createParser()
         return new Parser(
             $this->encoder,
             $this->decoder,
-            $this->signerFactory,
             $this->claimFactory
         );
     }
@@ -84,7 +76,6 @@ public function constructMustConfigureTheAttributes()
 
         $this->assertAttributeSame($this->encoder, 'encoder', $parser);
         $this->assertAttributeSame($this->decoder, 'decoder', $parser);
-        $this->assertAttributeSame($this->signerFactory, 'signerFactory', $parser);
         $this->assertAttributeSame($this->claimFactory, 'claimFactory', $parser);
     }
 
@@ -192,7 +183,7 @@ public function parseMustReturnANonSignedTokenWhenSignatureIsNotInformed()
         $parser = $this->createParser();
         $token = $parser->parse('a.a.');
 
-        $this->assertAttributeEquals(['typ' => 'JWT', 'alg' => 'none'], 'header', $token);
+        $this->assertAttributeEquals(['typ' => 'JWT', 'alg' => 'none'], 'headers', $token);
         $this->assertAttributeEquals(['aud' => $this->defaultClaim], 'claims', $token);
         $this->assertAttributeEquals(null, 'signature', $token);
         $this->assertAttributeSame($this->encoder, 'encoder', $token);
@@ -227,7 +218,7 @@ public function parseShouldReplicateClaimValueOnHeaderWhenNeeded()
 
         $this->assertAttributeEquals(
             ['typ' => 'JWT', 'alg' => 'none', 'aud' => $this->defaultClaim],
-            'header',
+            'headers',
             $token
         );
 
@@ -253,8 +244,6 @@ public function parseShouldReplicateClaimValueOnHeaderWhenNeeded()
      */
     public function parseMustReturnASignedTokenWhenSignatureIsInformed()
     {
-        $signer = $this->getMock(Signer::class);
-
         $this->decoder->expects($this->at(1))
                       ->method('jsonDecode')
                       ->willReturn(['typ' => 'JWT', 'alg' => 'HS256']);
@@ -267,16 +256,12 @@ public function parseMustReturnASignedTokenWhenSignatureIsInformed()
                       ->method('base64UrlDecode')
                       ->willReturn('aaa');
 
-        $this->signerFactory->expects($this->any())
-                      ->method('create')
-                      ->willReturn($signer);
-
         $parser = $this->createParser();
         $token = $parser->parse('a.a.a');
 
-        $this->assertAttributeEquals(['typ' => 'JWT', 'alg' => 'HS256'], 'header', $token);
+        $this->assertAttributeEquals(['typ' => 'JWT', 'alg' => 'HS256'], 'headers', $token);
         $this->assertAttributeEquals(['aud' => $this->defaultClaim], 'claims', $token);
-        $this->assertAttributeEquals(new Signature($signer, 'aaa'), 'signature', $token);
+        $this->assertAttributeEquals(new Signature('aaa'), 'signature', $token);
         $this->assertAttributeSame($this->encoder, 'encoder', $token);
     }
 }
diff --git a/test/Parsing/DecoderTest.php b/test/Parsing/DecoderTest.php
index e737b24c..51d727bd 100644
--- a/test/Parsing/DecoderTest.php
+++ b/test/Parsing/DecoderTest.php
@@ -22,21 +22,10 @@ public function jsonDecodeMustReturnTheDecodedData()
     {
         $decoder = new Decoder();
 
-        $this->assertEquals(['test' => 'test'], $decoder->jsonDecode('{"test":"test"}'));
-    }
-
-    /**
-     * @test
-     *
-     * @covers Lcobucci\JWT\Parsing\Decoder::jsonDecode
-     *
-     * @expectedException \RuntimeException
-     */
-    public function jsonDecodeMustRaiseExceptionWhenResultIsNotAnArray()
-    {
-        $decoder = new Decoder();
-
-        $decoder->jsonDecode('"test"');
+        $this->assertEquals(
+            (object) ['test' => 'test'],
+            $decoder->jsonDecode('{"test":"test"}')
+        );
     }
 
     /**
diff --git a/test/SignatureTest.php b/test/SignatureTest.php
index 54b36be7..c29787e1 100644
--- a/test/SignatureTest.php
+++ b/test/SignatureTest.php
@@ -33,9 +33,8 @@ protected function setUp()
      */
     public function constructorMustConfigureAttributes()
     {
-        $signature = new Signature($this->signer, 'test');
+        $signature = new Signature('test');
 
-        $this->assertAttributeSame($this->signer, 'signer', $signature);
         $this->assertAttributeEquals('test', 'hash', $signature);
     }
 
@@ -48,7 +47,7 @@ public function constructorMustConfigureAttributes()
      */
     public function toStringMustReturnTheHash()
     {
-        $signature = new Signature($this->signer, 'test');
+        $signature = new Signature('test');
 
         $this->assertEquals('test', (string) $signature);
     }
@@ -67,8 +66,8 @@ public function verifyMustReturnWhatSignerSays()
                      ->method('verify')
                      ->willReturn(true);
 
-        $signature = new Signature($this->signer, 'test');
+        $signature = new Signature('test');
 
-        $this->assertTrue($signature->verify('one', 'key'));
+        $this->assertTrue($signature->verify($this->signer, 'one', 'key'));
     }
 }
diff --git a/test/Signer/BaseSignerTest.php b/test/Signer/BaseSignerTest.php
index 58b11b59..5baf70ee 100644
--- a/test/Signer/BaseSignerTest.php
+++ b/test/Signer/BaseSignerTest.php
@@ -61,7 +61,7 @@ public function modifyHeaderShouldChangeAlgorithmAndType()
     public function signMustReturnANewSignature()
     {
         $this->assertEquals(
-            new Signature($this->signer, 'test'),
+            new Signature('test'),
             $this->signer->sign('test', '123')
         );
     }
diff --git a/test/Signer/FactoryTest.php b/test/Signer/FactoryTest.php
deleted file mode 100644
index 8ca977ea..00000000
--- a/test/Signer/FactoryTest.php
+++ /dev/null
@@ -1,202 +0,0 @@
-<?php
-/**
- * This file is part of Lcobucci\JWT, a simple library to handle JWT and JWS
- *
- * @license http://opensource.org/licenses/BSD-3-Clause BSD-3-Clause
- */
-
-namespace Lcobucci\JWT\Signer;
-
-use Lcobucci\JWT\Signer\Ecdsa\Sha256 as EcdsaSha256;
-use Lcobucci\JWT\Signer\Ecdsa\Sha384 as EcdsaSha384;
-use Lcobucci\JWT\Signer\Ecdsa\Sha512 as EcdsaSha512;
-use Lcobucci\JWT\Signer\Hmac\Sha256 as HmacSha256;
-use Lcobucci\JWT\Signer\Hmac\Sha384 as HmacSha384;
-use Lcobucci\JWT\Signer\Hmac\Sha512 as HmacSha512;
-use Lcobucci\JWT\Signer\Rsa\Sha256 as RsaSha256;
-use Lcobucci\JWT\Signer\Rsa\Sha384 as RsaSha384;
-use Lcobucci\JWT\Signer\Rsa\Sha512 as RsaSha512;
-
-/**
- * @author Luís Otávio Cobucci Oblonczyk <lcobucci@gmail.com>
- * @since 0.1.0
- */
-class FactoryTest extends \PHPUnit_Framework_TestCase
-{
-    /**
-     * @test
-     *
-     * @covers Lcobucci\JWT\Signer\Factory::__construct
-     */
-    public function constructMustConfigureTheCallbacks()
-    {
-        $callback = function () {
-        };
-        $factory = new Factory(['test' => $callback]);
-
-        $expected = [
-            'HS256' => [$factory, 'createHmacSha256'],
-            'HS384' => [$factory, 'createHmacSha384'],
-            'HS512' => [$factory, 'createHmacSha512'],
-            'RS256' => [$factory, 'createRsaSha256'],
-            'RS384' => [$factory, 'createRsaSha384'],
-            'RS512' => [$factory, 'createRsaSha512'],
-            'ES256' => [$factory, 'createEcdsaSha256'],
-            'ES384' => [$factory, 'createEcdsaSha384'],
-            'ES512' => [$factory, 'createEcdsaSha512'],
-            'test' => $callback
-        ];
-
-        $this->assertAttributeEquals($expected, 'callbacks', $factory);
-    }
-
-    /**
-     * @test
-     *
-     * @uses Lcobucci\JWT\Signer\Factory::__construct
-     *
-     * @covers Lcobucci\JWT\Signer\Factory::create
-     * @covers Lcobucci\JWT\Signer\Factory::createHmacSha256
-     */
-    public function createMustBeAbleReturnAHmacSha256Signer()
-    {
-        $factory = new Factory();
-
-        $this->assertInstanceOf(HmacSha256::class, $factory->create('HS256'));
-    }
-
-    /**
-     * @test
-     *
-     * @uses Lcobucci\JWT\Signer\Factory::__construct
-     *
-     * @covers Lcobucci\JWT\Signer\Factory::create
-     * @covers Lcobucci\JWT\Signer\Factory::createHmacSha384
-     */
-    public function createMustBeAbleReturnAHmacSha384Signer()
-    {
-        $factory = new Factory();
-
-        $this->assertInstanceOf(HmacSha384::class, $factory->create('HS384'));
-    }
-
-    /**
-     * @test
-     *
-     * @uses Lcobucci\JWT\Signer\Factory::__construct
-     *
-     * @covers Lcobucci\JWT\Signer\Factory::create
-     * @covers Lcobucci\JWT\Signer\Factory::createHmacSha512
-     */
-    public function createMustBeAbleReturnAHmacSha512Signer()
-    {
-        $factory = new Factory();
-
-        $this->assertInstanceOf(HmacSha512::class, $factory->create('HS512'));
-    }
-
-    /**
-     * @test
-     *
-     * @uses Lcobucci\JWT\Signer\Factory::__construct
-     *
-     * @covers Lcobucci\JWT\Signer\Factory::create
-     * @covers Lcobucci\JWT\Signer\Factory::createRsaSha256
-     */
-    public function createMustBeAbleReturnARsaSha256Signer()
-    {
-        $factory = new Factory();
-
-        $this->assertInstanceOf(RsaSha256::class, $factory->create('RS256'));
-    }
-
-    /**
-     * @test
-     *
-     * @uses Lcobucci\JWT\Signer\Factory::__construct
-     *
-     * @covers Lcobucci\JWT\Signer\Factory::create
-     * @covers Lcobucci\JWT\Signer\Factory::createRsaSha384
-     */
-    public function createMustBeAbleReturnARsaSha384Signer()
-    {
-        $factory = new Factory();
-
-        $this->assertInstanceOf(RsaSha384::class, $factory->create('RS384'));
-    }
-
-    /**
-     * @test
-     *
-     * @uses Lcobucci\JWT\Signer\Factory::__construct
-     *
-     * @covers Lcobucci\JWT\Signer\Factory::create
-     * @covers Lcobucci\JWT\Signer\Factory::createRsaSha512
-     */
-    public function createMustBeAbleReturnARsaSha512Signer()
-    {
-        $factory = new Factory();
-
-        $this->assertInstanceOf(RsaSha512::class, $factory->create('RS512'));
-    }
-
-    /**
-     * @test
-     *
-     * @uses Lcobucci\JWT\Signer\Factory::__construct
-     *
-     * @covers Lcobucci\JWT\Signer\Factory::create
-     * @covers Lcobucci\JWT\Signer\Factory::createEcdsaSha256
-     */
-    public function createMustBeAbleReturnAEcdsaSha256Signer()
-    {
-        $factory = new Factory();
-
-        $this->assertInstanceOf(EcdsaSha256::class, $factory->create('ES256'));
-    }
-
-    /**
-     * @test
-     *
-     * @uses Lcobucci\JWT\Signer\Factory::__construct
-     *
-     * @covers Lcobucci\JWT\Signer\Factory::create
-     * @covers Lcobucci\JWT\Signer\Factory::createEcdsaSha384
-     */
-    public function createMustBeAbleReturnAEcdsaSha384Signer()
-    {
-        $factory = new Factory();
-
-        $this->assertInstanceOf(EcdsaSha384::class, $factory->create('ES384'));
-    }
-
-    /**
-     * @test
-     *
-     * @uses Lcobucci\JWT\Signer\Factory::__construct
-     *
-     * @covers Lcobucci\JWT\Signer\Factory::create
-     * @covers Lcobucci\JWT\Signer\Factory::createEcdsaSha512
-     */
-    public function createMustBeAbleReturnAEcdsaSha512Signer()
-    {
-        $factory = new Factory();
-
-        $this->assertInstanceOf(EcdsaSha512::class, $factory->create('ES512'));
-    }
-
-    /**
-     * @test
-     *
-     * @uses Lcobucci\JWT\Signer\Factory::__construct
-     *
-     * @covers Lcobucci\JWT\Signer\Factory::create
-     *
-     * @expectedException InvalidArgumentException
-     */
-    public function createMustRaiseExceptionWhenIdIsInvalid()
-    {
-        $factory = new Factory();
-        $factory->create('testing');
-    }
-}
diff --git a/test/TokenTest.php b/test/TokenTest.php
index ea961b60..ae5f1879 100644
--- a/test/TokenTest.php
+++ b/test/TokenTest.php
@@ -41,7 +41,7 @@ public function constructMustInitializeAnEmptyPlainTextTokenWhenNoArgumentsArePa
     {
         $token = new Token();
 
-        $this->assertAttributeEquals(['alg' => 'none'], 'header', $token);
+        $this->assertAttributeEquals(['alg' => 'none'], 'headers', $token);
         $this->assertAttributeEquals([], 'claims', $token);
         $this->assertAttributeEquals(null, 'signature', $token);
     }
@@ -67,12 +67,58 @@ public function setEncoderMustConfigureTheEncoderAttribute()
      * @uses Lcobucci\JWT\Token::__construct
      *
      * @covers Lcobucci\JWT\Token::getHeader
+     *
+     * @expectedException \OutOfBoundsException
      */
-    public function getHeaderMustReturnTheConfiguredHeader()
+    public function getHeaderMustRaiseExceptionWhenHeaderIsNotConfigured()
     {
         $token = new Token(['test' => 'testing']);
 
-        $this->assertEquals(['test' => 'testing'], $token->getHeader());
+        $token->getHeader('testing');
+    }
+
+    /**
+     * @test
+     *
+     * @uses Lcobucci\JWT\Token::__construct
+     *
+     * @covers Lcobucci\JWT\Token::getHeader
+     */
+    public function getHeaderMustReturnTheRequestedHeader()
+    {
+        $token = new Token(['test' => 'testing']);
+
+        $this->assertEquals('testing', $token->getHeader('test'));
+    }
+
+    /**
+     * @test
+     *
+     * @uses Lcobucci\JWT\Token::__construct
+     * @uses Lcobucci\JWT\Claim\Basic::__construct
+     * @uses Lcobucci\JWT\Claim\Basic::getValue
+     *
+     * @covers Lcobucci\JWT\Token::getHeader
+     */
+    public function getHeaderMustReturnValueWhenItIsAReplicatedClaim()
+    {
+        $token = new Token(['jti' => new EqualsTo('jti', 1)]);
+
+        $this->assertEquals(1, $token->getHeader('jti'));
+    }
+
+    /**
+     * @test
+     *
+     * @uses Lcobucci\JWT\Token::__construct
+     *
+     * @covers Lcobucci\JWT\Token::getHeaders
+     */
+    public function getHeadersMustReturnTheConfiguredHeader()
+    {
+        $token = new Token(['test' => 'testing']);
+
+        $this->assertEquals(['test' => 'testing'], $token->getHeaders());
     }
 
     /**
@@ -126,29 +172,43 @@ public function getClaimShouldReturnTheClaimValueWhenItExists()
      *
      * @uses Lcobucci\JWT\Token::__construct
      *
-     * @covers Lcobucci\JWT\Token::getSignature
+     * @covers Lcobucci\JWT\Token::verify
+     *
+     * @expectedException BadMethodCallException
      */
-    public function getSignatureMustReturnTheConfiguredSignature()
+    public function verifyMustRaiseExceptionWhenTokenIsUnsigned()
     {
-        $signature = $this->getMock(Signature::class, [], [], '', false);
-        $token = new Token([], [], $signature);
+        $signer = $this->getMock(Signer::class);
 
-        $this->assertSame($signature, $token->getSignature());
+        $token = new Token();
+        $token->verify($signer, 'test');
     }
 
     /**
      * @test
      *
      * @uses Lcobucci\JWT\Token::__construct
+     * @uses Lcobucci\JWT\Token::setEncoder
+     * @uses Lcobucci\JWT\Token::getPayload
      *
      * @covers Lcobucci\JWT\Token::verify
-     *
-     * @expectedException BadMethodCallException
      */
-    public function verifyMustRaiseExceptionWhenTokenIsUnsigned()
+    public function verifyShouldReturnFalseWhenTokenAlgorithmIsDifferent()
     {
-        $token = new Token();
-        $token->verify('test');
+        $signer = $this->getMock(Signer::class);
+        $signature = $this->getMock(Signature::class, [], [], '', false);
+
+        $signer->expects($this->any())
+               ->method('getAlgorithmId')
+               ->willReturn('HS256');
+
+        $signature->expects($this->never())
+                  ->method('verify');
+
+        $token = new Token(['alg' => 'RS256'], [], $signature);
+        $token->setEncoder($this->encoder);
+
+        $this->assertFalse($token->verify($signer, 'test'));
     }
 
     /**
@@ -162,16 +222,22 @@ public function verifyMustRaiseExceptionWhenTokenIsUnsigned()
      */
     public function verifyMustDelegateTheValidationToSignature()
     {
+        $signer = $this->getMock(Signer::class);
         $signature = $this->getMock(Signature::class, [], [], '', false);
 
+        $signer->expects($this->any())
+               ->method('getAlgorithmId')
+               ->willReturn('HS256');
+
         $signature->expects($this->once())
                   ->method('verify')
+                  ->with($signer, $this->isType('string'), 'test')
                   ->willReturn(true);
 
-        $token = new Token([], [], $signature);
+        $token = new Token(['alg' => 'HS256'], [], $signature);
         $token->setEncoder($this->encoder);
 
-        $this->assertTrue($token->verify('test'));
+        $this->assertTrue($token->verify($signer, 'test'));
     }
 
     /**