The title is rather misleading (not the submitter's fault -- it's the title of the original post). It's not "array comparison that's independent of timing", whatever that might have meant, it's "array comparison whose timing is independent of the contents of they arrays". (To avoid side-channel attacks on your crypto.)<p>I think there's an oversimplification in the first section, though it may be a deliberate one for the sake of clarity. Your goal isn't really to know each byte with 95% confidence, it's to know enough about the bits that you can do a small search and be likely to find the right key / hash / whatever. Which means that what you really want to do is to have a model of how the timings (noise and all) relate to the actual values, and keep going until the <i>total entropy</i> of the secret you're trying to extract gets small enough.