Thanks for the explaination. Even if this is a protected and valid use of DMCA, it doesn't strike me as a strong move for a company confident in its product.

Thanks for the explaination. Even if this is a protected and valid use of DMCA, it doesn't strike me as a strong move for a company confident in its product. This isn't what I would consider "technologically sophisticated cryptattack", but instead just looking at some screenshots or slides and doing a quick observational analysis on them. If the analysis were wrong, it might just come down to "well that's how our designers ended up making the slides/video" (replacing each word with a hash of itself), then I think it might make more sense to issue a statement that the advertising materials weren't exactly matching how the encryption works. Not sure if that would open them up to libel though.