Digital Watermarking
Rob Farraher
Ken Pickering
Lim Vu
Big Brother Industries
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© 1984
Joe Wahoo decides to be a law abiding
citizen and purchase music online from
Big Brother Industries
Joe Wahoo
Big Brother Industries
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© 1984
He purchases licenses to listen the
mp3s he has downloaded
He also owns the latest SDMI mp3
player
SDMI?
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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?
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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
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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
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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?
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Digital information embedded within
any digital media that can later be
detected and extracted
Characteristics
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Perceptible or Imperceptible
Robust or Fragile
Watermarking Applications
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Applications include
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Authentication and verification
Fingerprinting
Ownership Assertion
Content labeling
Usage Control
Authentication and Verification
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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
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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
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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
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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
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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
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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
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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
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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
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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.