code: private function decrypt($ciphertext) {
  		$plaintext = base64_decode($ciphertext);
  		if ($this->status) {
  			$plaintext = trim( @mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $this->key, base64_decode($ciphertext), MCRYPT_MODE_CBC, base64_decode($this->iv)) );
  			$plaintext_array = json_decode($plaintext, TRUE);
  			if ($plaintext_array)
  				$plaintext = $plaintext_array;
  		}
  
  		return $plaintext;
  	}
docs: decrypt
  ID: Dekripsi session | EN: Session Decryption
  @param string $ciphertext
  @return mixed