# Upgrading from 3.3 to 3.4

## Auth

 - The `Auth::hash_password()` method has been removed. Use `Auth::hash()` instead.

## Cache

- Added a new `Memcached` driver.
- The `APC` driver was deprecated. Use `APCu` or other drivers instead.
- The `Memcache` driver was deprecated. Use `Memcached` or other drivers instead.
- The `MemcacheTag` driver was deprecated.

## Core

- The `Core::CODENAME` constant was deprecated.

## Database

- The `MySQL` driver has been removed. Use `PDO` or other drivers instead.

## Encrypt

- Now `Encrypt` acts as an interface and a new `OpenSSL` driver for it was added.
- The `Mcrypt` driver was deprecated. Use `OpenSSL` instead.

## Security

- The `Security::strip_image_tags()` method has been removed for [security reasons](https://github.com/kohana/kohana/issues/107) as it is not reliable to parse and sanitize HTML with regular expressions. You should either encode HTML tags entirely, e.g. with `HTML::chars()`, or use a more robust HTML filtering solution such as [HTML Purifier](http://htmlpurifier.org).

## Validation

- The `Validation::as_array()` method has been removed. Use `Validation::data()` instead.
