SDMI? Secure Digital Music Initiative Who: Conglomerate of world-wide recording, consumer electronic, and information technology corporations Purpose: To design and implement a copyright protection scheme for music How: Digital Watermarking
MP3 Nirvana? Joe’s friend, Dave, sends him a new NSync mp3 Joe loves the song and wants to listen to it on his new mp3 player But a slight problem arises
Rejection Dave’s mp3 turns out to be watermarked only for his use Joe’s mp3 player rejects Dave’s NSync mp3 because it detects the mp3 watermark registered to Dave
Breakin’ the Law Joe decides to hack and remove the watermark on Dave’s mp3 so his mp3 player will play the song He uses the attacks described in a research paper released by Princeton’s professor Felton
What Is Watermarking? Digital information embedded within any digital media that can later be detected and extracted Characteristics Perceptible or Imperceptible Robust or Fragile
Watermarking Applications Applications include Authentication and verification Fingerprinting Ownership Assertion Content labeling Usage Control
Authentication and Verification Use of any type of watermark to authenticate files and digital media Verification allow users to download files in an insecure channel Similar to a cryptographic hash sent with a file but much more difficult for an attacker to forge and insert a correct watermark
Fingerprinting Imperceptible watermarks used to label content for identification purposes If content is copied and improperly used, the watermark can be viewed and the source of the copying can be found If Joe Wahoo distributes music with his watermark embedded, any authority with the watermark directory can track him down
Ownership Assertion A watermark can be placed in a music document to declare who owns/ produces the music This is basically used to remove the “value” of the data, in a lot of circumstances since it asserts it as the owners intellectual property or copyright
Content Labeling Involves using watermarks to carry and deliver data on the media they are embedded within Uses within databases and search engines Advantage in that description of data is internally stored within file
Usage Control A proposed use for watermarking could be to control accessing and copying music. The theory is that when a copy is made, some counter in the file is decremented. This requires a monopoly on copying.
Problems with Watermarking Must not be audible and change little content of MP3 file Plain text to “message” will always be available Must be universally accepted by software developers that make encoding software and players
Plaintext/Ciphertext Attacks The plaintext is always available for the MP3 file so, therefore, any attackers can see the additions the watermark makes (and remove them) Ease of removal is variable, depending on the algorithm used
Universal Acceptance As long as users can rip MP3’s without watermarks, piracy will always proliferate If the MP3 players and portable devices play unwatermarked MP3’s, there’s no point in having the system in place at all
Conclusion Watermarking is useful in a lot of circumstances. Digital music isn’t one of them. If someone wants to remove music watermarking, with all current algorithms, they will be able to. RIP Napster. We’ll miss you.