What Is Hash Function?

This next one seems to get things done in a blur, if you know what we mean, but it is genuinely one of the best buddies for you out there. Hashes are like barcodes in that they're short strings of numbers that represent more significant pieces of information, but unlike barcodes, hashes are random and unreadable: you can't look at them and know what meaning they have. However, you can use them to find other information in a database by comparing their value against known values. Hashes are valid for indexing and locating items in databases because it's much easier to find shorter values than longer ones. They're also used in encryption: when you encrypt something using hashing, you essentially create a code that will be impossible for anyone else to decrypt without knowing the original message or key used for encryption, and even then, it will still take some time to decrypt! One instance of a hash function is called folding. This takes an original value, divides it into several parts, adds the parts and uses the last four remaining digits as the hashed value or key. It's like when you fold a piece of paper in half, then fold it in half again and again until you have only one square left. If you had written your name on that square, you would now have a unique identifier: your name spelled out differently based on how many times you folded that piece of paper. So if someone wanted to send you a message by folding their piece of paper and writing your name on it, and they folded it enough times so that the squares were too small to read, you could still figure out what they wrote just by knowing how many times they folded their paper!