We're dealing with keys and we'll learn how to generate a key a 128 bit key. And when we are asked to type our password in a typical pain code when entering your office, we're usually asked to insert four characters only four characters, which are the password. They are four characters out of 10 possible characters out of zero to nine. If an attacker will try to brute force the password, he will have a key space of 10 to the power of four. There is 10 optional characters to the power of the four that have been chosen as the password in math, we call it a base 10 quick math There are 10,000 possible options. There is the key space that we're using one, only one out of 10,000 possible keys is the right password.

Now let's take it to another area, alphabet characters from A to Z. There are 26 characters. So when we use a password on our computer, and we were asked to insert only a lowercase alphabet, no uppercase, no symbols, no numbers, only eight lowercase alphabet. Our key space is 26 to the power of eight, and that is a huge number. When we use binary digits, our base is two there is only one And zero, we are actually mapping to bits of input to the power of n bits output possible state. So, if we had a key that is two to the power of two, we have four possible keys and that is with no permutations.

If we take permutations, our key space is much larger two to the power of three, eight possible keys, two to the power of 16 more than 65,000 keys and so on. Today, we are not using anything that is less than two to the power of 128 bit 256 bit and 512 bit