Encryption and cryptography are two words we hear all the time. We want to hide our information from prying eyes. Cryptography is the math that makes it work, encryption is the process that does the work. We’re not going to talk math, I promise. We’ll talk encryption instead, that’s more fun.

Lock and Key

Let’s start with two kinds of encryption. One way encryption and two way encryption. If I encrypt something with a one-way method, then I can’t get it back. It’s like locking a padlock then throwing away the key.

That sounds silly, right? Why on earth would I lock a padlock and throw away the key?

Well, this being computers it’s not exactly like locking a padlock and throwing away the key. When you use one-way encryption, what you get back is a unique combination of characters that means eactly what you encrypted. You can’t decrypt it to find out what it was to begin with, but you can encrypt a word and see if it matches that weird looking string of characters you have.

Sounds weird, right? It’s actually the method used for passwords. That way no one has any idea what your password is, they just know what the hash looks like. You type your password in, the system encrypts it and compares it to what they have on file. If it matches, then bingo, you’re in.

Here’s an example, suppose Tony Stark’s password is ShellHead. Then the password could look like:

$_OIhfVvnK$.UYVFlACkTI

That doesn’t look anything like ShellHead, does it? So figuring out what the password is just by looking at that is impossible.

Suppose I type in ShellHea instead of ShellHead. Then the password could look like:

$_jCoO/YKY$GeTermseGL2

That isn’t anything like ShellHead’s password, so I’m not getting in.

How do people break passwords then? It’s called a dictionary attack. They run through all the words in the dictionary in various combinations and encrypt each one. Then they compare it to the password string of characters and if it matches, they have your password.

That’s why choosing a good password is so important! You don’t want people breaking into your system, do you? Imagine the damage someone could do if they broke into Batman’s computer.