As a key part of a campaign to embed encryption software that it could crack into widely used computer products, the U.S. National Security Agency arranged a secret $10 million contract with RSA, one of the most influential firms in the computer security industry.

Documents leaked by former NSA contractor Edward Snowden show that the NSA created and promulgated a flawed formula for generating random numbers to create a "back door" in encryption products, the New York Times reported in September. RSA became the most important distributor of that formula by rolling it into a software tool called Bsafe that is used to enhance security in personal computers and many other products.

Security researchers have successfully broken one of the most secure encryption algorithms, 4096-bit RSA, by listening – yes, with a microphone — to a computer as it decrypts some encrypted data.

The attack is fairly simple and can be carried out with rudimentary hardware. The repercussions for the average computer user are minimal, but if you’re a secret agent, power user, or some other kind of encryption-using miscreant, you may want to reach for the Rammstein when decrypting your data. This acoustic cryptanalysis, carried out by Daniel Genkin, Adi Shamir (who co-invented RSA), and Eran Tromer, uses what’s known as a side channel attack. A side channel is an attack vector that is non-direct and unconventional, and thus hasn’t been properly secured.