Doesn’t matter whether it’s a CakePHP app for a client, your own personal CMS, or any other web based application. If your passing around passwords or other sensitive info you should really implement SSL. SSL provides 2 main perks to your visitors.
Once you implement SSL certificates on your server you’ll want to require secure connections using Apache’s rewrite module. Now I won’t dwell on the creation and signing of certificates, its already well documented. If your just starting out though,heres a few links I recommend;