What's the link between security and processors?

A lot of newer processors have parts of their core dedicated to doing AES instructions. This means the 'cost' of encryption, in terms of power and processor use is less, since these parts do that one job more efficiently and faster. This means its easier to encrypt things, and as such you have better security.

You can use this for things like openssl, or encrypting the hard drive, or any library designed to use it, with less of a hit on performance for regular tasks.

Modern processors incorporate various protection techniques which facilitate an increase in the overall security of the system.

One example is the flagging of data areas in memory as No-eXecute in order to prevent over- and underrun vulnerabilities.

An older and more fundamental capability is the protection mechanisms provided by the virtual memory management system. The very nature of the conventional VMM techniques prevent one process from accessing another process's memory.