i get that SHA256 isn’t considered “encryption”, it’s something to do with hashing. so, if i encrypt “hello” into a random string of characters, why is it said to be impossible to decrypt it back to “hello”? if you had a maths equation like P = (k * 10 / G) / (4x * 5gl), it’s possible to work backwards to find the value of k or g eventually. why not with SHA256? is it something to do with random numbers?
In: Mathematics
>is it something to do with random numbers?
Not really. Hash algorithms have to give the same answer for a given set of data every time they run. If they used random numbers, that would not be possible. It has more to do with the XOR operation. Most hash algorithms work by XOR-ing the data with various strings of binary numbers.
The binary operation XOR takes in two digits (each either 0 or 1) and produces a 1 if exactly one of those digits is a 0 and the other is a 1. Its possible output look like this:
* 1 & 0 = 1
* 0 & 1 = 1
* 1 & 1 = 0
* 0 & 0 = 0
If you use XOR to combine a string of data with some other string of bits, you will get the same answer each time, because the operation is consistent. But it is not easy to reverse: if tell you the answer is 0, does that mean my input bits were both 0 or both 1? You have no way of knowing.
This is why hash algorithms are (relatively) easy to run, but very difficult to reverse.
Latest Answers