Reading between the lines: Lessons from the SDMI challenge

The Secure Digital Music Initiative is a consortium ofparties interested in preventing piracy of digital music,
and to this end they are developing architectures for con-
tent protection on untrusted platforms. SDMI recently
held a challenge to test the strength of four watermark-
ing technologies, and two other security technologies.
No documentation explained the implementations of the
technologies, and neither watermark embedding nor de-
tecting software was directly accessible to challenge par-
ticipants. We nevertheless accepted the challenge, and
explored the inner workings of the technologies. We re-
port on our results here.