I would substitute "scramble" with "magic". Something like: "The password is scrambled [1] so no one can see what it was originally. Second, this scrambling method ensures the result is the same length as every other password. Third, that very similar passwords, like 'aaaa' and 'aaab' [2] come out very different looking. And it's impossible [3] to descramble it to the original password."

[1] Using a mathematical concept known as "hashing"---see [link] for futher information.

[2] These are bad passwords; used for an example only.

[3] Not quite impossible, but very darned near impossible. See [link] for more information.