Songs of the Universe

In our introduction, we discuss encryption keys, passwords and ciphers. We tell how keys are built by the computer, how they are used, andy why you must change your password often.

Here we will try to enlighten you as to the general workings of cryptography and passwords in as painless a way as we can. We will also try to stay away from any math. Well, there is a little, but easy stuff, we promise. Enjoy.

Private Key Encryption

Part 1 - History of Cryptography
Part 2 - Keys Public and Private
Part 3 - On Complexity and Cracking
Part 4 - Encrypting or Enciphering

Before we actually get started, a small word of caution: If you already know about this stuff, you might consider skipping this section entirely. This is an introduction and we have tried to keep it simple. So if you decide to continue on, you do so at your own risk. You may find that your brain resembles week-old oatmeal before you finish. Don't say we didn't warn you.

History of (Western) Cryptography

As far back as civilization goes, there has always been the urge to say, "I know a secret and you don't. Nah nuh nah nuh na na!" an attitude that usually led to the quick demise of the holder of the secret.

In times of war, which is always, there arose a real need to send messages and not have them fall into the wrong hands. Sending messengers didn't work too well, as torture was too willingly and happily applied in order to separate the message from the container.

However, with such clever innovations as reading and writing (we're not too sure which came first.), things got a bit more complex.

The early Romans came up with the idea of shaving the messenger's head, tattooing the message and letting the hair grow back before sending him on his way. Since he didn't know the message, he couldn't be tortured. This didn't work out too well for urgent messages, however. There was also the messy problem of disposing of the message once read, which led to an acute shortage of available messengers. Something clearly had to be done. Enter Julius Caesar.

The Caesar Cipher

Not the same as the Caesar Salad, but similar. The salad has tossed greens where the cipher has tossed alphabet. Clever Julius came up with the idea of scrambling the letters of the alphabet before writing a message so that no one could read it.

What he came up with was the simple method of shifting the letters of the alphabet to the right by three. Thus the number 3 became the ...

Encryption Key

All encryption systems use a key. It is called a key because it is used to unlock the secret message. It is more familiar to us today as the password. The problem with keys is that if you continue to use the same key long enough, someone will figure out what it is, or more likely just steal it. Once the key is discovered, the entire system is compromised. So you must change the password often.

So it would appear logical to never use the same key or password twice. This is what Songs of the Universe does. We will return to this subject a bit later.

It would also seem logical that the more complex the key the harder it is to guess. More than one safe was cracked during WWII simply by dialing Hitler's birthday.

In our computer driven society today, we commonly use passwords or phrases. These also have their problems. One is that they must be simple and easy to remember, which also makes them easier to guises, especially for a computer.

These days we use incredibly long numbers as keys. This makes them very complex indeed. Cryptography relies on the huge quantity of possible combinations of numbers for its secrecy. Let's make a key to use to scramble the alphabet as Caesar did. Here's an example, and we promise this will be the only math you will see here.

Of Bits And Bytes and Characters

Get a coin and place it on the table in front of you. Forget that it is a coin and call it a 'bit'. You have one bit, so that coin is the same as a 1 bit binary number. Binary? Binary means two. Two, because there are two states for the coin or bit to be in. Heads or Tails. Up, Down. Just two states and no other. (And no, edges don't count). Now add another coin next to the first. Now the two coins have four states:

1 - Heads, Heads
2 - Heads, Tails
3 - Tails, Heads
4 - Tails, Tails

Four states, so we have now doubled the complexity. It's twice as hard to guess the correct combination. For each bit (coin) you add, you make it twice as hard to figure out the correct number. If we used one of these four states as our key to scramble the alphabet, it would not take long to guess which is the correct one. All we have to do is try each combination and see if it deciphers our message. So we must add more bits until we get a number so long that it would take years to guess it.

Continue adding coins until you have eight. Eight is a small but important number to a computer. Why? Because there are 256 possible combinations of numbers that can be made from 8 bits. With this many, you can assign one number to every letter of the English alphabet, both upper and lower case, along with all the digits and punctuation and still have some left over.

On your screen, you see strings of letters. Each letter is called a character, and is made up of eight bits. In geek-speak each character or letter is called a 'byte'.

The byte, or 8 bits, is also the smallest data size a computer can handle efficiently. Handling bits by themselves is cumbersome and requires a lot of fiddling around. Although we talk of key size in bits, we do so only to show how complex the numbers can get. We will look into this a bit more when we discuss cracking a code.

Using the Key

OK, got the concept now? Here's a simple example you are bound to be familiar with: The Password. You type in your secret password, or words as the case may be. The computer changes the letters into one long series of numbers. Then it scrambles them around by a method only it knows. It takes this scrambled number and matches it to the original number it made up when you chose the password. If the two match, you are in. You just used cryptography. Congratulations.

OK, now on to our next heart-pounding installment on...

Keys, Public and Private



Back to top...