diff --git a/src/LaravelOTP.php b/src/LaravelOTP.php
index 706b47d..f63e60a 100644
--- a/src/LaravelOTP.php
+++ b/src/LaravelOTP.php
@@ -33,95 +33,51 @@ final public function now(): string
         return $this->at();
     }
 
-    /**
-     * @return string
-     * return TOTP at previous timeframe
-     */
     final public function last(): string
     {
         return $this->at(-1);
     }
 
-    /**
-     * @return string
-     * return TOTP at next timeframe
-     */
     final public function next(): string
     {
         return $this->at(1);
     }
 
-    /**
-     * @param int $offset
-     * @return string
-     * return TOTP at custom timeframe
-     */
     final public function at(int $offset = 0): string
     {
         return $this->generateTOTP($this->secret, $offset);
     }
 
-    /**
-     * @param int $length
-     * @return string
-     * Generate Secret Key
-     */
     final public function generateSecretKey(): string
     {
         return substr(str_shuffle('ABCDEFGHIJKLMNOPQRSTUVWXYZ234567'), 0, 32);
     }
 
-    /**
-     * @return int
-     * Return current time
-     */
     private function getCurrentTimestamp(): int
     {
-        return floor(time() / 30); // Time steps of 30 seconds
+        return floor(time() / 30);
     }
 
-    /**
-     * @param int $counter
-     * @return string
-     * Return HOTP at specific counter
-     */
     final public function atCounter(int $counter): string
     {
         return $this->generateHOTP($this->secret, $counter);
     }
 
-    /**
-     * @param string $secretKey
-     * @param int $timeStepOffset
-     * @return string
-     * Generate TOTP at specific timeframe
-     */
     private function generateTOTP(string $secretKey, int $timeStepOffset = 0): string
     {
         $timestamp = $this->getCurrentTimestamp() + $timeStepOffset;
 
-        return $this->generateHOTP($secretKey, $timestamp); // TOTP is HOTP with a time-based counter
+        return $this->generateHOTP($secretKey, $timestamp);
     }
 
-    /**
-     * @param string $secretKey
-     * @param int $counter
-     * @return string
-     * Generate HOTP at specific counter
-     */
     private function generateHOTP(string $secretKey, int $counter): string
     {
-        // Decode the base32 secret key
         $key = $this->base32_decode($secretKey);
+        $counter = pack('J', $counter);
 
-        // Pack the counter into an 8-byte binary string (big endian)
-        $counter = pack('N*', 0) . pack('N*', $counter);
+        $hash = hash_hmac('sha512', $counter, $key, true);
 
-        // Generate HMAC-SHA1 hash using the secret key and packed counter
-        $hash = hash_hmac('sha1', $counter, $key, true);
-
-        // Extract dynamic binary code (truncated hash)
-        $offset = ord($hash[19]) & 0xf;
+        $offset = ord($hash[63]) & 0xf;
         $binaryCode = (
             ((ord($hash[$offset]) & 0x7f) << 24) |
             ((ord($hash[$offset + 1]) & 0xff) << 16) |
@@ -129,14 +85,9 @@ private function generateHOTP(string $secretKey, int $counter): string
             (ord($hash[$offset + 3]) & 0xff)
         );
 
-        // Convert binary code into a 6-digit OTP
         return str_pad($binaryCode % 1000000, 6, '0', STR_PAD_LEFT);
     }
 
-    /**
-     * @param string $input
-     * @return string
-     */
     private function base32_decode(string $input): string
     {
         $alphabet = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567';
@@ -147,7 +98,6 @@ private function base32_decode(string $input): string
         foreach (str_split($input) as $char) {
             $buffer = ($buffer << 5) | strpos($alphabet, $char);
             $bitsLeft += 5;
-
             if ($bitsLeft >= 8) {
                 $bitsLeft -= 8;
                 $output .= chr(($buffer >> $bitsLeft) & 0xff);
@@ -157,63 +107,34 @@ private function base32_decode(string $input): string
         return $output;
     }
 
-    /**
-     * @param string $otp
-     * @param string|null $secret
-     * @return bool
-     * Verify TOTP
-     */
     final public function verifyTOTP(string $otp, string $secret = null): bool
     {
         if ($secret !== null) {
             $this->secret = $secret;
         }
 
-        $secretKey = $this->secret;
-
-        // Check the OTP for the current time step, the previous, and the next one
         for ($i = -1; $i <= 1; $i++) {
-            $calculatedOtp = $this->generateTOTP($secretKey, $i);
-            if ($calculatedOtp === $otp) {
-                return true; // OTP is valid
+            if ($this->generateTOTP($this->secret, $i) === $otp) {
+
+                return true;
             }
         }
 
-        return false; // OTP is invalid
+        return false;
     }
 
-    /**
-     * @param string $otp
-     * @param int $counter
-     * @param string|null $secret
-     * @return bool
-     * Verify HOTP at specific counter
-     */
     final public function verifyHOTP(string $otp, int $counter, string $secret = null): bool
     {
         if ($secret !== null) {
             $this->secret = $secret;
         }
 
-        $calculatedOtp = $this->generateHOTP($this->secret, $counter);
-        return $calculatedOtp === $otp; // Return true if OTP matches, otherwise false
+        return $this->generateHOTP($this->secret, $counter) === $otp;
     }
 
-
-    /**
-     * @param string $label
-     * @param string $issuer
-     * @param string|null $secretKey
-     * @param int|null $counter
-     * @return string
-     * Generate URL to be used on QR Codes for Authenticator apps
-     */
     final public function generateUrl(string $label, string $issuer, string $secretKey = null, int $counter = null): string
     {
-        $method = 'totp';
-        if ($counter !== null) {
-            $method = 'hotp';
-        }
+        $method = $counter !== null ? 'hotp' : 'totp';
         return "otpauth://" . $method . '/' . $label . "?secret=" . ($secretKey ?? $this->secret) . '&issuer=' . $issuer . ($counter ? '&counter=' . $counter : '');
     }
 }
diff --git a/src/LaravelOTPServiceProvider.php b/src/LaravelOTPServiceProvider.php
index c7f18a2..7d31816 100644
--- a/src/LaravelOTPServiceProvider.php
+++ b/src/LaravelOTPServiceProvider.php
@@ -4,12 +4,12 @@
 
 use Illuminate\Support\ServiceProvider;
 
-class LaravelOTPServiceProvider extends ServiceProvider
+final class LaravelOTPServiceProvider extends ServiceProvider
 {
     /**
      * Bootstrap the application services.
      */
-    public function boot()
+    public function boot(): void
     {
 
         if ($this->app->runningInConsole()) {
@@ -24,7 +24,7 @@ public function boot()
     /**
      * Register the application services.
      */
-    public function register()
+    public function register(): void
     {
         // Register the main class to use with the facade
         $this->app->singleton('laravel-otp', function () {