Welcome back. I'm going to go over
the general outline of
applied cryptography over the next few lessons.
I'll introduce you to
a concept tree that fits all the different ideas
together and will help us apply what we
need for this course in terms of applied cryptography.
Now, the goal here is to give
you enough of an understanding of
applied cryptography so that you have
the ability to differentiate between
kinds of algorithms and know
which kind of algorithm to use in a given instance.
We're going to basically do
an overview so you have the context.
But what I'm not going to be doing in these lessons is
to present you the math
and the theory behind applied cryptography.
You can get a really excellent in-depth discussion
if you read the very excellent textbook
called "Cryptography Engineering: Design
Principles and Practical Applications"
by Ferguson, Schneier, and Khono.
So the basic outline of what we're going to talk about
today is outlined in general
in this concept tree that I've created.
So this concept tree is based on relating each of
the concepts of applied cryptography to one another.
This is a subset of
applied cryptography that we want to use for this course.
Now, applied cryptography of course,
is a very large topic,
but we're only going to touch upon a small subset of it.
But nonetheless, the concepts
that we're going to talk about can be thought
of as being related to one
another as drawn here in this concept tree.
I'm showing you this tree so that you can understand
better where things fit
together and how they fit together conceptually.
This concept tree is not
based on the importance of the concept,
it's just how they fit
together is what I'm highlighting here.
So with that said, first,
we're going to go and start
with looking at block ciphers,
and then block cipher modes of operation.
Then we're going to work our way up
this part of the concept tree
to symmetric key encryption.
Next, we're going to talk about
an introduction to the idea
behind asymmetric cryptography,
and then we're going to talk
about public and private keys.
Then we're going to see
asymmetric cryptography in action.
Then we're going to move on to talk
about hash functions and work our
way up this concept tree to talk
about cryptographic hash functions.
Last, we're going to talk
about message authentication codes.
So at the end of the series on cryptography basics,
you will be able to select
the proper kind of algorithm to use.
One, to encrypt sensitive data, two,
to authenticate messages, and three,
to prevent data tampering.
Now, we have a lot to cover, so let's get started.