answer the following questions:

Schneier says that using mass surveillance to find terrorists would have so many false alarms that it would not be useful. But what if we were to come up with a technique that was extremely accurate -- would we still get too many false alarms? Lets say we get accuracy of 99.99%, almost perfect, and that 1 in every million people scanned was really a terrorist. Would that be enough to bring the false alarms down? Could we use this technique to reliably find the terrorist? Explain why or why not.

The NSA, CIA and others have been gathering mass surveillance since 9/11 (and even before.) Schneier points out it did not help find the Boston bombers, the underwear bomber, or the liquid bombers. What did he say was a more effective technique, and why is it better than mass surveillance? Explain.

What is the difference between mass surveillance and targeted surveillance? Explain.

An 80 bit encryption key (roughly the length of a 10 character password) is twice as hard to use as a 40 bit key (similar length to a 5 character password.) How much harder is it to crack it? By harder, I mean how much longer would it take to crack. I'm not asking in absolute time, just compare it to breaking the 40 bit key.

If encryption is so good, how do the NSA and similar agencies get access to encrypted information? Explain.