removed a call to the validation class, as it's overkill for a simple preg_match
diff --git a/system/libraries/Encrypt.php b/system/libraries/Encrypt.php
index 6d0735a..aabf90d 100644
--- a/system/libraries/Encrypt.php
+++ b/system/libraries/Encrypt.php
@@ -141,9 +141,7 @@
 	{

 		$key = $this->get_key($key);

 		

-		$this->CI->load->library('validation');

-		

-		if ($this->CI->validation->valid_base64($string) === FALSE)

+		if ( ! preg_match('/[^a-zA-Z0-9\/\+=]/', $string))

 		{

 			return FALSE;

 		}