"The great advantage of being a writer is that you can spy on people. You're there, listening to every word, but part of you is observing. Everything is useful to a writer, every scrap, even the longest and most boring of luncheon parties."

The goal of cryptography is to make it so that the cost of breaking the system exceeds the value of the information protected.

The quantum Fourier transform is the key to the exponential speedup in Shor's algorithm.