Three out of three? That could be the score for the U.S. National Security Agencys cryptographic most wanted list of 2012.

In January 2012, it saw Internet traffic anonymizing tool Tor (The Onion Router), Linux distribution Tails (The Amnesic Incognito Live System) and disk encryption system TrueCrypt as the biggest threats to its ability to intercept Internet traffic and interpret other information it acquires.

Since then, flaws have been found in Tor, and the FBI has unmasked Tor users. A vulnerability was found in Tails allowing attackers to determine users IP addresses.

Whilea source-code audit gave TrueCrypt a relatively clean bill of health in April, TrueCrypts anonymous developersinexplicably abandoned the software a few weeks later, warning it was insecure.

That the NSA considered these tools dangerous is perhaps little surprise: In July it was revealed that the agencys XKeyScore traffic interception tool contains rules for tracking who visited the websites of the Tor and Tails projects.

But now German magazine Der Spiegel has published further documents from the cache leaked by Edward Snowden, including one outlining, on page 25, the tools the NSA most wanted to crack in order to intercept and decrypt its targets communications.

The tools were ranked by their impact, from trivial to catastrophic, and their use risk, from current highest priority targets down to experimentation by technical thought leaders.

In the slide deck, the NSA explained that, with rare exceptions, it only developed application-specific solutions based on those two criteria, impact and use risk. In a resource-constrained environment, it said, the need for responses to current threats would always trump speculative work on threats that might become more widespread. Der Spiegel had something to say about those constraints: Of the NSAs 2013 budget of over $10 billion, some $34.3 million was allocated to Cryptanalysis and Exploitation Services.

Top of the NSAs list of major or catastrophic threats, capable of causing a majority or near-total loss or lack of insight into the highest-priority targets communications or online presence, were Tor, Tails and TrueCrypt.

Of course, its unlikely that the published attacks on Tor and Tails were developed by the NSAbut with the Tor's unmasking attack costing researchers just $3,000, the NSA could certainly have done something similar with its budget over the last three years. Although some of the wilder conspiracy theories linking TrueCrypts demise to the NSA have evaporated, there is still no convincing explanation for why the developers abandoned a tool that had just come through a code audit with no major flaws found.

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Tor, TrueCrypt, Tails topped the NSA's 'most wanted' in 2012, per newly revealed Snowden leaks