Cryptography Reference
In-Depth Information
Chapter 5
Life After DES: New Methods,
New Attacks
We have learned two important and modern encryption methods and know
quite a few things about cryptanalysis. In this chapter, we will undertake an
expedition through the colorful world of modern algorithms. It cannot be more
than a short expedition though, and it shouldn't be. Moreover, our discussion
will be limited to symmetric methods — you have already come to know the two
popular asymmetric methods in Section 4.5. I refer readers who want to know
about more algorithms and their analysis to the comprehensive and clearly
written work by Schneier [SchnCr].
But before we start dealing with new methods, we will first have a look at
very practical things. To be able to use cryptographic algorithms in programs,
or — more frequently — to evaluate the security of cryptographic programs, you
need to know a thing or two about the implementation of such algorithms.
5.1
Implementation of Algorithms
The best algorithm won't do any good if it is badly implemented from the
cryptographic viewpoint. This section will discuss three things everybody needs
to know before they embed a cryptographic algorithm in another program:
