It just so happens that my congressional representative, Boucher, was responsible for the language added which allows bypassing the restrictions, and there are very few conditions where that is permitted. There is research and there is the clause to preserve Fair Use (and other rights under copyright law), but that does not extend or cover the clause concerning traffiking in decryption software, unless that has been added by legal precedent in case law (that I’m unaware of). If you provide software to decrypt or assist someone in decryption, it violates the DMCA the way it was written. The use of decryption software for research or fair use is permitted, but it’s illegal to supply it.

I recognize that it’s a fine distinction, esp. for ephemeral works. Marijuana is a reasonable analogy in my state: it’s legal (again, in my state) to grow and possess personal amounts, but it is illegal to sell it, or for anyone to sell it to you. Anyone who sells it is violating the law, even if that is the only way you can obtain it. In the case decrypting a file for Fair Use is use (legal); selling is trafficking (providing a decryption algorithm); growing for personal use (also legal) is writing your own software from scratch to decrypt. (this is where the analogy breaks down because it’s legal to sell growing kits, but it’s not legal to sell decryption kits.)