The entire architecture is created and maintained based on that premise rather than simply implementing point solutions for, say, access control or encryption. The challenge throughout, of course, is to balance high levels of security with network, system and application performance, plus responsiveness and 24x7 availability. With a 'gold rush' mentality still at play, it seems that every man, woman and dog with a computer is either already on or about to leap onto the e-bandwagon. So the notion of security needs to include making sure that you're working with trusted, proven e-providers. User access security is, ideally, based on the principle of 'something you have and something you know'.
Procedural security is enabled through the granting of rights to functions and data.
Good database and workflow design, encompassing security considerations, can minimize the impact on application usability. HTTP is a seriously heavyweight protocol, and is ideal for security purposes. Firewalls can then restrict by protocol, and only one port is used. Next, we have embedded problems. Buggy software has led to security breaches, so pro-actively monitor identified problems and apply the necessary patches.