Authenticated Encryption

Often when two parties communicate over a network, they have two main security goals: privacy and authentication. In fact, there is compelling evidence that one should never use encryption without also providing authentication [8, 14]. Many solutions for the privacy and authentication problems have existed for decades, and the traditional approach to solving both simultaneously has been to combine them in a straightforward manner using so-called “generic composition.” However, recently there have been a number of new constructions which achieve both privacy and authenticity simultaneously, often much faster than any solution which uses generic composition. In this article we will explore the various approaches to achieving both privacy and authenticity, the so-called “Authenticated Encryption” problem. We will often abbreviate this as simply “AE.” We will start with generic composition methods and then explore the newer combined methods.