Encryption: Explain it to me Like I’m 5
Say you wanted to send a letter to somebody but the message content is pretty sensible. It has a big secret that should only ever see the person who is meant to read. If someone else had their hands on it you would have more trouble than you could imagine. Just let’s say you’re very motivated to keep the message out of the wrong hands. How would you do that, then? Would you please hire armed guards? Put it in a sturdy lockbox? What about putting a code on it, and if the message auto-destructs the wrong PIN? That is a good analogy if “encryption” is what it is. It is a way to manipulate your message, so that nobody else can understand it. The other person knows how you were manipulating it, and when they get your message, they can reverse the process. So it matters not if someone else has a copy of the information. It makes no sense whatsoever. In a nutshell, that is encryption.
OK How?
Let’s put some terms in first. You already know that encryption is called the act of scrambling a message. Encryption is the practical component of a field called cryptography. The method we use to manipulate the message is called a “cipher” to scramble it All cryptography is based on the art of cipher making. The cipher is the bit you’ll have to share with the other person who’ll get the message. To mix the message, you use the instructions incorporated in the cipher. The person on the other end will then use the cypher to un-mix the whole thing. What exactly does a cipher look like? Substitution cipher is the simplest example. This is one for which you do not need a computer, but has in fact been of practical use in the history. Good enough to generals in the army, and so on. What you do, in the message, you take a letter and then you replace it with something else. Another letter in the alphabet could be some of the symbols you made up.
All About Keys These Days “3/3.1124.png” Conceptually the ciphers we use on computers these days are the same as other cipher types. The key difference is that knowing the workings of the cipher is not enough to reverse its effects. How could it be? It is thanks to random inclusion. As you probably already know by definition randomness is patternless. If you randomly choose 100 numbers then nothing connects them to each other. The ciphers we use for computers leave a little gap in them, with a random sequence of symbols to be filled in. These form then an integral part of how the information is scrambled by the cipher. That means that simply knowing how the cipher generally works will not help you decode a specific message. There’s a unique string of symbols known as the encryption key as part of the cipher’s functionality. To make the message meaningful again you need both this key and the cipher. The ciphers are so complicated that they only have any hope of being applied by a computer. Which means just guessing the key is the only way forward. Except there’s a little problem with that …
“3/3.1125.jpg” Well, it’s not technically impossible, but it’s so hard it could be impossible. Remember to randomize the keys which means that there is no way to predict or derive the key from anything else. That means you are going to have to guess breaking the encryption. How long does it take for this? OK let’s give you a quick example of an idea. Let’s say you want to steal a bike. I don’t know why you desperately want just one. The bike is fitted with a four-digit combination padlock. Each digit from 0-9 can be anything. Since there are four digits it means that between 0000 and 9999 is the number that will unlock the bike. That is ten thousand possible numbers. If you had to guess any number and you could do one number per second it would take you nearly three hours to go through them all. You probably will hit the right number sooner than that, of course. In the first half of possible numbers there is a 50 percent chance that it will be. That is about an hour and a half, “only.” You probably would still be caught long before you actually found the answer.We inventedasymmetric encryption to solve the issue of getting people’s keys without giving them access to decryption. There are two of those keys now. Each of you can do just one job: encrypt or decrypt. So, you can make one public safely. Anyone who wants to email you can use your public key. Only your private key can decipher it. To send back information the other way you use the public key for the other person. Lastly, there is hashing which is not exactly data encryption but is related to it. You get a unique signature when you hash one piece of data. If there was only one bit different in the data then the hash looks completely different. The actual figures are not in the hash itself. Hashes are used to check whether the data was altered. We use it for passwords too. A Facebook-like provider does not have your actual password on file. Just its hash. It gets hashed once again when you type in a password. If both hashes exactly match you get access.
What Cryptography Does for Us It’s not difficult to find an example of cryptography that will help you out in your everyday life. You’re probably connected to a WiFi network right now, for example, or will be there today at some point. In fact, the WiFi passcode is an encryption key although it is a rather simple and short one. You might have figured out, based on what you read above, that it’s an example of symmetric encryption. By a long shot, that is not the only place. Here are some common cases of use where the encryption improves your life.
Disk and Device Encryption
Information about our computer drives and smartphones is likely to contain some very sensitive information and obviously there is a need to protect it. Encryption can be a big help. To turn your Windows Mac or Linux PC into a data fortress, there are plenty of full disk encryption programs out there. The same applies to Android phones and tablets, and iOS. These days they come by default with full disk encryption enabled. With disk encryption in place it doesn’t matter if someone gets access to your data physically. They have zero chance of getting to your information without a decryption key.