How Encryption Programs can be attacked

[Carsten Wiethoff]

I've always assumed that freely available encryption packages could be hacked by the NSA and other government bodies. I also imagine that PGP can be broken too?

GnuPG, which is the subject of the article, is the most common implementation of PGP.
The described procedure can be used to attack any encryption program, not by cryptoanalysis, but by monitoring the running decryption program and analysing the steps it takes during decryption.