It does not matter how slowly you go, so long as you do not stop.
Security means a variety of things to users and developers. In a web context, security is related to preventing injection of malicious code in the running application. Likewise, security relates to actions aimed at preventing disclosure of private data. Finally, security relates to building applications (and sections of an application) that only authenticated and authorized users can access.
The aspect of security that application developers deal with more frequently is certainly the authentication and authorization of users. Recently, more and more websites started implementing authentication also via popular social providers. Although ...