A couple of questions for the Freeper Crypto Whiz Kids:
1. When doing a dycrypt how do you test for success?
2. Why can’t these powerful quantum systems be defeated by putting a finite limit on the number of breakin attempts. That could be a very large number and still be safe.
It seems to me that the super-super-computers have to work off line to avoid this easy fix. How is that possible? Or is it?
I’m not exactly a “Crypto Whiz Kid” but I’ll give it a go.
Current crypto systems are based on functions that can be computed quickly in one direction, but are hard (meaning not computationally practical) to compute in the other direction. The threat here is that quantum computing would be able to do the reverse computation quickly.
So, checking for success is not necessary and counting breakin attempts would not help. Just calculate the key and use it.