It quickly became apparent though, that the RIAA was really only concerned with one thing: copy protection. Whether anyone would buy the copy-protected music, or products designed to play only copy-protected music, didn't seem to bother them. (It was ironic then that the chosen logo tag line was "Digital Music Access Technology", when preventing access was paramount.) Further, the dominant RIAA participants were lawyers with unrealistic expectations for security - whom few of technical people had the courage to confront. I caused quite a stir with a short presentation dealing with "cryptography 101" realities like shimming and key discovery -realities that made it clear they could not get the level of protection they wanted.
A few months into the process, out of desperation or technical ignorance or both, SDMI chose a protection technology approach based on digital watermarks. It was obvious to technically competent participants, (amongst whom I un-humbly count myself), that you could not make a watermark sufficiently robust for persistent content protection with the relevant perceptual audio codecs such as MP3. NetActive stopped participating at that point, because it was clear that the technology would not work. (And the meetings we missed were in places like Florence, Paris, and Tokyo - sigh.) Anyway, the scheme was cracked soon after it was made available for outside scrutiny..and the RIAA sent their lawyers after some of the people who did the cracking !
SDMI is dead, and the problems that SDMI considered took another ten years to work themselves out in the marketplace, without the benefit of a simiar unbrella technical organization. It is ironic that the eventual industry solution for audio, was the recognition that copy protection for audio is overkill and many consumers will pay for convenience and quality even in the face of "free" competition. Of course, it took Apple's brilliant iTunes ecosystem to do that, whcih was only a gleam in Steve Jobs' eye in 1999.