(The previous two parts of this essay appeared earlier.)
Or maybe not. There is a rough consensus among cryptography experts that the theoretical underpinnings of encryption - the mathematical foundations - remain untouched. The problem lies in the implementation and the environment in which encryption is used. Edward Snowden probably knows better than most what the true situation is, and here's how he put it:
Encryption works. Properly implemented strong crypto systems are one of the few things that you can rely on. Unfortunately, endpoint security is so terrifically weak that NSA can frequently find ways around it.
That's a hugely important clue as to what we need to do. It tells us that there is nothing wrong with crypto as such, just the corrupted implementations of otherwise strong encryption techniques. That is confirmed by recent leaks of information that show computer software companies complicit in weakening the supposedly safe products they sell - truly a betrayal of the trust placed in them by their customers.
The good news is that we have an alternative. For the last few decades, free software/open source has been building a software ecosystem that is outside the control of the traditional computer industry. That makes it much harder for the NSA to subvert, since the code is developed openly, which allows anyone to inspect it and look for backdoors - secret ways to spy on and control the software.
That's not to say free software is completely immune to security issues. Many open source products come from companies, and it's possible that some of them may have been pressured to weaken aspects of their work. Free software applications might be subverted as they are converted from the source code, which can be easily checked for backdoors, to the binaries - the versions that actually run on a computer - which can't. There is also potential for online holdings of open source programs to be broken into and tampered with in subtle ways.
Despite those problems, open source is still the best hope we have when it comes to using strong encryption. But in the wake of Snowden's revelations, the free software community needs to take additional precautions so as to minimise the risk that code is still vulnerable to attacks and subversion by spy agencies.
Beyond such measures, the open source world should also start thinking about writing a new generation of applications with strong crypto built in. These already exist, but are often hard to use. More needs to be done to make them appropriate for general users: the latter may not care much about the possibility that the NSA or GCHQ is monitoring everything they do online, but if they are offered great tools that make it easy to resist such efforts, more people may adopt them, just as millions have switched to the Firefox browser - not because it supports open standards, but because it is better.
Although the scale of the spying revealed by Snowden's leaks is staggering, and the leaks about the thoroughgoing and intentional destruction of the Internet's entire trust and security systems are shocking, there is no reason for despair. Even in the face of widespread public ignorance and indifference to the threat such total surveillance represents to democracy, as far as we know we can still use strong encryption implemented in open source software to protect our privacy.
Indeed, this may be an opportunity for open source to be embraced by a wider public, since we now know definitively that commercial software cannot be trusted, and is effectively spyware that you have to pay for. And just as Moore's Law allows the NSA and GCHQ to pull in and analyse ever-more of our data, so free software, too, can benefit.
For as Moore's Law continues to drive down the prices of personal computing devices - whether PCs, smartphones or tablets - so more people in developing countries around the world are able to acquire them. Many will adopt free software, since Western software companies often price their products at unreasonably-high levels compared to local disposable income. As open source is used more widely, so the number of people keen and able to contribute to such projects will grow, the software will improve, and more people will use it. In other words, there is a virtuous circle that produces its own kind of scaling that will help to counteract the more malign kind that underlies the ever-expanding surveillance activities of the NSA and GCHQ. As well as tools of repression, computers can also be tools of resistance when powered by free software, which is called that for a reason.