{@code HashedCredentialsMatcher} implementation that expects the stored {@code AuthenticationInfo} credentials to be MD2 hashed. <p/> <b>Note:</b> the MD2, <a href="http://en.wikipedia.org/wiki/MD5">MD5</a> and <a href="http://en.wikipedia.org/wiki/SHA_hash_functions">SHA-1</a> algorithms are now known to be vulnerable to compromise and/or collisions (read the linked pages for more). While most applications are ok with either of these two, if your application mandates high security, use the SHA-256 (or higher) hashing algorithms and their supporting <code>CredentialsMatcher</code> implementations.</p>