diff --git a/app/Services/Cipher/ARGON2I.php b/app/Services/Cipher/ARGON2I.php
index 8ed91947..58202d11 100644
--- a/app/Services/Cipher/ARGON2I.php
+++ b/app/Services/Cipher/ARGON2I.php
@@ -4,12 +4,12 @@ namespace App\Services\Cipher;
 
 class ARGON2I extends BaseCipher
 {
-    public function hash($value, $salt = '')
+    public function hash($value, $salt = ''): string
     {
         return password_hash($value, PASSWORD_ARGON2I);
     }
 
-    public function verify($password, $hash, $salt = '')
+    public function verify($password, $hash, $salt = ''): bool
     {
         return password_verify($password, $hash);
     }
diff --git a/app/Services/Cipher/BCRYPT.php b/app/Services/Cipher/BCRYPT.php
index 7f9ec885..a2903698 100644
--- a/app/Services/Cipher/BCRYPT.php
+++ b/app/Services/Cipher/BCRYPT.php
@@ -4,12 +4,12 @@ namespace App\Services\Cipher;
 
 class BCRYPT extends BaseCipher
 {
-    public function hash($value, $salt = '')
+    public function hash($value, $salt = ''): string
     {
         return password_hash($value, PASSWORD_BCRYPT);
     }
 
-    public function verify($password, $hash, $salt = '')
+    public function verify($password, $hash, $salt = ''): bool
     {
         return password_verify($password, $hash);
     }
diff --git a/app/Services/Cipher/BaseCipher.php b/app/Services/Cipher/BaseCipher.php
index c2dedbbf..7c227709 100644
--- a/app/Services/Cipher/BaseCipher.php
+++ b/app/Services/Cipher/BaseCipher.php
@@ -2,19 +2,24 @@
 
 namespace App\Services\Cipher;
 
-abstract class BaseCipher implements EncryptInterface
+abstract class BaseCipher
 {
     /**
-     * {@inheritdoc}
+     * Encrypt given string with given salt.
+     *
+     * @param string $value
+     * @param string $salt
      */
-    public function hash($value, $salt = '')
-    {
-    }
+    public abstract function hash($value, $salt = '');
 
     /**
-     * {@inheritdoc}
+     * Verify that the given hash matches the given password.
+     *
+     * @param string $password
+     * @param string $hash
+     * @param string $salt
      */
-    public function verify($password, $hash, $salt = '')
+    public  function verify($password, $hash, $salt = '')
     {
         return hash_equals($hash, $this->hash($password, $salt));
     }
diff --git a/app/Services/Cipher/EncryptInterface.php b/app/Services/Cipher/EncryptInterface.php
deleted file mode 100644
index 32d30763..00000000
--- a/app/Services/Cipher/EncryptInterface.php
+++ /dev/null
@@ -1,26 +0,0 @@
-<?php
-
-namespace App\Services\Cipher;
-
-interface EncryptInterface
-{
-    /**
-     * Encrypt given string with given salt.
-     *
-     * @param string $value
-     * @param string $salt
-     *
-     * @return string
-     */
-    public function hash($value, $salt = '');
-
-    /**
-     * Verifies that the given hash matches the given password.
-     *
-     * @param string $password
-     * @param string $hash
-     *
-     * @return bool
-     */
-    public function verify($password, $hash);
-}
diff --git a/app/Services/Cipher/MD5.php b/app/Services/Cipher/MD5.php
index 16862320..84047650 100644
--- a/app/Services/Cipher/MD5.php
+++ b/app/Services/Cipher/MD5.php
@@ -4,10 +4,7 @@ namespace App\Services\Cipher;
 
 class MD5 extends BaseCipher
 {
-    /**
-     * Once MD5 hash.
-     */
-    public function hash($value, $salt = '')
+    public function hash($value, $salt = ''): string
     {
         return md5($value);
     }
diff --git a/app/Services/Cipher/PHP_PASSWORD_HASH.php b/app/Services/Cipher/PHP_PASSWORD_HASH.php
index 2eab9c09..e98a3533 100644
--- a/app/Services/Cipher/PHP_PASSWORD_HASH.php
+++ b/app/Services/Cipher/PHP_PASSWORD_HASH.php
@@ -4,12 +4,12 @@ namespace App\Services\Cipher;
 
 class PHP_PASSWORD_HASH extends BaseCipher
 {
-    public function hash($value, $salt = '')
+    public function hash($value, $salt = ''): string
     {
         return password_hash($value, PASSWORD_DEFAULT);
     }
 
-    public function verify($password, $hash, $salt = '')
+    public function verify($password, $hash, $salt = ''): bool
     {
         return password_verify($password, $hash);
     }
diff --git a/app/Services/Cipher/SALTED2MD5.php b/app/Services/Cipher/SALTED2MD5.php
index fdfce361..3a765c49 100644
--- a/app/Services/Cipher/SALTED2MD5.php
+++ b/app/Services/Cipher/SALTED2MD5.php
@@ -4,10 +4,7 @@ namespace App\Services\Cipher;
 
 class SALTED2MD5 extends BaseCipher
 {
-    /**
-     * MD5 hash with salt.
-     */
-    public function hash($value, $salt = '')
+    public function hash($value, $salt = ''): string
     {
         return md5(md5($value).$salt);
     }
diff --git a/app/Services/Cipher/SALTED2SHA256.php b/app/Services/Cipher/SALTED2SHA256.php
index adda5a22..207202d4 100644
--- a/app/Services/Cipher/SALTED2SHA256.php
+++ b/app/Services/Cipher/SALTED2SHA256.php
@@ -4,10 +4,7 @@ namespace App\Services\Cipher;
 
 class SALTED2SHA256 extends BaseCipher
 {
-    /**
-     * SHA256 hash with salt.
-     */
-    public function hash($value, $salt = '')
+    public function hash($value, $salt = ''): string
     {
         return hash('sha256', hash('sha256', $value).$salt);
     }
diff --git a/app/Services/Cipher/SALTED2SHA512.php b/app/Services/Cipher/SALTED2SHA512.php
index 4268eb36..50b62cf5 100644
--- a/app/Services/Cipher/SALTED2SHA512.php
+++ b/app/Services/Cipher/SALTED2SHA512.php
@@ -4,10 +4,7 @@ namespace App\Services\Cipher;
 
 class SALTED2SHA512 extends BaseCipher
 {
-    /**
-     * SHA512 hash with salt.
-     */
-    public function hash($value, $salt = '')
+    public function hash($value, $salt = ''): string
     {
         return hash('sha512', hash('sha512', $value).$salt);
     }
diff --git a/app/Services/Cipher/SHA256.php b/app/Services/Cipher/SHA256.php
index 26c2bb82..e1d2ca48 100644
--- a/app/Services/Cipher/SHA256.php
+++ b/app/Services/Cipher/SHA256.php
@@ -4,10 +4,7 @@ namespace App\Services\Cipher;
 
 class SHA256 extends BaseCipher
 {
-    /**
-     * Once SHA256 hash.
-     */
-    public function hash($value, $salt = '')
+    public function hash($value, $salt = ''): string
     {
         return hash('sha256', $value);
     }
diff --git a/app/Services/Cipher/SHA512.php b/app/Services/Cipher/SHA512.php
index 32dae6ed..0aec6fb3 100644
--- a/app/Services/Cipher/SHA512.php
+++ b/app/Services/Cipher/SHA512.php
@@ -4,10 +4,7 @@ namespace App\Services\Cipher;
 
 class SHA512 extends BaseCipher
 {
-    /**
-     * Once SHA512 hash.
-     */
-    public function hash($value, $salt = '')
+    public function hash($value, $salt = ''): string
     {
         return hash('sha512', $value);
     }