- Information security is critical to the world we live in,
yet it's been with us for hundreds of years,
and as you'll see, it's more than just
keeping information secret.
Securing information and information systems
goes back at least as far 480 BC
when the Persian king, Xerxes, put his invasion plans
for Greece onto encrypted tablets,
so he could safely share them with his distant allies.
About 400 years later, the Roman general, Julius Caesar,
invented what we call the Caesar cipher
in order to protect his military messages.
The cipher wheel itself was part of an entire system
which included strict procedures for how to handle
the messages, as well as the cipher tools.
In recent years, our computers do the encryption
and decryption for us.
They convert our data into digital nonsense,
and then return it into its original form when we need it.
So how do we define information security today?
Because the law is taking an ever increasing role
in information security affairs, let's take a look
at section 3552 in title 44 of the United States code.
Not surprisingly, the definition is detailed,
so let's step through it.
The term information security means protecting information
and information systems from unauthorized access, use,
or disclosure, disruption, modification, or destruction.
By protecting information from these threats,
we can achieve three goals.
First, confidentiality so we can keep
our secrets under control.
Second, integrity which means that our information
is not corrupted.
And third, availability so we can see our information
whenever we want.
You'll commonly hear the term CIA Triad
when information security professionals talk about
the three goals of confidentiality,
integrity, and availability of information.
How do these goals help us today?
Take, for example, modern banking.
Today we can manage our money privately online,
we can withdraw cash from an ATM any time, day or night,
and we can quickly place an online order
for just about anything.
But without information security,
none of these things would be possible.