When we use keys, the key space is much larger than we think. So if we use a tree, pick key two to the power of three, there are eight possible keys. There's 100110111011001000101 and 010. But there are also permutations. permutation is the amount of possible combination and that makes our key much more larger. So if we will do permutation of eight, that is eight times seven times six times five times four times three times two.

It adds up to 40,000 more than 40,000 possible permutation from the eight possible keys that we get in our two to the power of three bit key. permutations are being used in just about any cipher algorithm out there. Trust me, permutations are key to make your cipher text much more confusing for any attacker. We will look at how do we use permutations and how do we map the different bitstream In the next video