A Few Thoughts on Cryptographic Engineering: On the NSA

Let me tell you the story of my tiny brush with the biggest crypto story of the year.

A few weeks ago I received a call from a reporter at ProPublica, asking me background questions about encryption. Right off the bat I knew this was going to be an odd conversation, since this gentleman seemed convinced that the NSA had vast capabilities to defeat encryption. And not in a 'hey,d'ya think the NSA has vast capabilities to defeat encryption?' kind of way.No, he'd already established the defeating. We were just haggling over the details.

Oddness aside it was a fun (if brief) set of conversations, mostly involving hypotheticals. If the NSA could do this, how might they do it? What would the impact be? I admit that at this point one of my biggest concerns was to avoid coming off like a crank. After all, if I got quoted soundingtoo much like an NSA conspiracy nut, my colleagues would laugh at me. Then I might not get invited to the cool security parties.

All of this is a long way of saying that I was totally unprepared for today's bombshell revelationsdescribing the NSA's efforts to defeat encryption. Not only does the worst possible hypothetical I discussed appear to be true, but it's true on a scale I couldn't even imagine. I'm no longer the crank. I wasn't even close to cranky enough.

And since I never got a chance to see the documents that sourced the NYT/ProPublica story -- and I would give my right armto see them-- I'm determined to make up for this deficit with sheer speculation. Which is exactly what this blog post will be.

'Bullrun' and 'Cheesy Name'

If you haven't read the ProPublica/NYT or Guardian stories, you probably should. The TL;DR is that the NSA has been doing some very bad things. At a combined cost of $250 million per year, they include:

How to break a cryptographic system

There's almost too much here for a short blog post, so I'm going to start with a few general thoughts. Readers of this blog should know that there are basically three ways to break a cryptographic system. In no particular order, they are:

So which code should we be concerned about? Which hardware?

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A Few Thoughts on Cryptographic Engineering: On the NSA