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Watermarking and Steganography . Watermarks. First introduced in Bologna, Italy in 1282 Dandy Roll presses pattern into drying paper Changes thickness of paper fibers Uses: By paper makers to identify their product Security for stamps, official documents. Stock certificates, money, etc.

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  • First introduced in Bologna, Italy in 1282
  • Dandy Roll presses pattern into drying paper
    • Changes thickness of paper fibers
  • Uses:
    • By paper makers to identify their product
    • Security for stamps, official documents.
    • Stock certificates, money, etc.
    • Chic
  • Other “watermarks”
    • Printing on plastic with a window.(Australian $10 note)
dandy roll
Pressed into paper during paper-making processDandy Roll
  • J. Plank Features
  • In-house watermark design
  • Computerized design process
  • Quick-change sleeves and sections              
  • Dandy roll
  • 7.25" diameter
  • Watermarking possible


dandy roll1
Dandy Roll
  • High grade stainless steel construction
  • Incorporates internal oscillating shower, internal pan, internal steam shower and external saveall pan
  • Extended Header Brush for easy cleaning of shower pipe
  • Wet pulp sprayed onto moving belt
  • Dandy Roll pressed into pulp
  • Dandy Roll looks like oversized printer’s roll covered with pattern
laser printed watermarks
Laser Printed “Watermarks”
  • Used on bond paper, but who uses bond paper?
    • Doesn’t work well in inkjets or laserjets
  • “Watermarks” with most print drivers…
printed watermarks
Printed Watermarks
  • Looks great
  • You can even put it in your PDF file…which is the problem!
  • No security
printed document authentication techniques
Printed Document Authentication Techniques
  • Microprinting – Print that is too small to produce or copy with conventional equipment
  • Intaglio –engraved pattern used to press ink with great force; raised letters
  • Letterpress – Ink rolled raised type, leaving depression. Used for printing numbers.
  • Simultan press – precise registration of front and back. (see-through register). Changing ink colors (rainbowing).
  • Optically variable inks (change color depending on angle)
  • Metal foils & threads embedded in paper
  • Security holograms
lessons for paper authentication
Lessons for paper authentication
  • Security features should convey a message relevant to the product.
    • Use iridescent ink to print the banknote denomination
  • Should obviously belong where they are
    • They become “embedded in the user’s cognitive model.”
  • Should be obvious
  • Should not have competitors
  • Should be standardized

Source: Security Engineering, Anderson

information hiding
Information Hiding
  • Copyright Marks:
    • Watermarks - Hidden copyright messages
    • Fingerprints – Hidden serial numbers
  • Steganography
    • Hidden messages.
  • Other applications:
    • Closed captioning (hidden in first 21 scan lines)
      • http://www.robson.org/gary/writing/nv-line21.html
    • Audio RDS (Radio Data Service)-like service
      • “What’s that song?”
watermarks for copyright policy
Watermarks for Copyright Policy
  • “never copy”
  • “copy only once”
  • “copy only at low quality”

JPMG Linnartz, “The ‘Ticket’ Concept for Copy Control Based on Embedded Signaling” (Anderson [504] ) Suggests a hash-based implementation of “copy only once:”

    • X is the ticket
    • Record h(h(X)) on DVD
    • Provided with X, DVD recorded stores h(X) on second-generation copy.
the broadcast flag
The Broadcast Flag
  • “Advanced Television Systems Committee Flag”
  • Enable/Disable:
    • high-quality digital output
    • Re-transmitting on an “unprotected” channel
  • In the future:
    • Time-shifting?
    • Disallow fast-forward through commercials
  • Required on all digital TV cards sold after July 2005
  • Only broadcast, not satellite or cable-transmitted.

“Losing Control of Your TV,” Technology Review, March 3, 2004


  • A hidden message that can't be found by humans
  • A hidden message that can't be found by an algorithm. A hidden message that can be found by an algorithm but not by a human.
  • A hidden message that can be found by some algorithms but not others.  

[Wayner 2004]

what is hidden
What is Hidden?

Defining "Hidden" is not easy

  • We run into the usual Goedel limits that prevents us from being logical about detection.
  • Humans are very different. Somemusicians have very, very good ears.
  • Some algorithms leave statistical anomalies. Themessage is often more random than the carriersignal. These statistics can give away the message.
who wants it
Who wants it?
  • Evil doers. If evil messages can't be seen by good people, evil will triumph. Osama bin Laden?
  • Good doers. If the good guys can communicate in secret, then goodwill triumph. U.S. forces
  • Content owners and copyright czars. Hidden messages can carry information about rights to view, copy, share, listen, understand, etc.
  • Software Developers. "Hidden" channels can be added to data structures without crashing previous versions. Steganography can fight bit rot.
models for steganography
Models for Steganography
  • Replace random number generators with the message.
    • This works if the random numbers are used in a detectable way.
    • TCP/IP, for instance, uses a random number for connections. Some grab this for their own purposes.
  • Replace noise with the message.
    • Just replace the least-significant bit.
    • Avoid the noise and tweak the salient features.
  • Anything not affected by compression.
    • If you have the freedom to change data without hurting the data, then you have the freedom to include another message.
models for steganography1
Models for Steganography
  • Structured Models
    • Run some compression algorithm in reverse
      • If the compression models the data accurately, then running it in reverse should spit out something that models the data well.
      • Huffman algorithms give common letters short bit strings and rare ones long ones.
    • Change the structure or the order.
      • GifEncoder, for instance, changes the order of the colors in the palette.
    • Synthesize something new and use the data to guide the synthesis.
      • Is the ghoul shooting at you in the game using a revolver or a machine gun? That's one bit.
  • The least significant bit of pixels or sound files is very popular.
  • Tweaking the LSB is only a small change. Less than 1%.
    • 140=10001100
    • 141=10001101
  • You can encrypt, too!

LSB modified to hide info

lsb modification
LSB Modification
  • Side Effects:
    • The data may not have the same statistical pattern as the least significant bits being replaced.
  • Add a lot of noise, and it’s obvious

4 LSB modified produces banding

8 out of 8 bits
8 out of 8 bits

All 8 bits

Bit 8 vs. Bit 1

wayner demos
Wayner Demos
  • Information hiding at the bit level:
    • http://www.wayner.org/books/discrypt2/bitlevel.php
  • Encoding information through list order:
    • http://www.wayner.org/books/discrypt2/sorted.php#note2
jpeg watermarking
JPEG Watermarking

“Hide and Seek: An

Introduction to Steganography”

IEEE Security & Privacy

Figure 2. Embedded information in a JPEG. (a) The unmodified

original picture; (b) the picture with the first chapter of The Hunting

of the Snark embedded in it.

mesh watermarking
Mesh Watermarking
  • Robust mesh watermarking, Emil Praun, Hugues Hoppe, Adam Finkelstein,July 1999Proceedings of the 26th annual conference on Computer graphics and interactive techniques
issues to evaluate
Issues to evaluate
  • “Capability”
    • Payload carrying ability
    • Detectability
    • Robustness
  • Securing information: Capacity is the wrong paradigm, Ira S. Moskowitz, LiWu Chang, Richard E. Newman , September 2002 Proceedings of the 2002 workshop on New security paradigms
sdmi secure digital media initiative
SDMI – Secure Digital Media Initiative
  • SDMI (200+ companies) published an “Open Letter to the Digital Community” with an SDMI Challenge.
    • Earn up to $10,000 for breaking their “watermarks”
    • Challenge from September 15, 2000 – October 7, 2000
  • SDMI Systems:
    • Designed to prevent “remixing” of privated CDs
    • Designed to survive MP3 compression
sdmi the academics
SDMI & The Academics
  • The Academics:
    • Scott Craver, Patrick McGregor, Min Wu, Bede Liu, (Dept. of Electrical Engineering, Princeton University)
    • Adam Stubblefield, Ben Swartzlander, Dan S. Wallach (Dept. of Computer Science, Rice University)
    • Edward W. Felten (Dept. of Computer Science, Princeton University)
  • What they did:
    • Successfully removed the digital watermark from the challenge audio samples.
  • How did they know they did it?
    • SDMI provided an “Oracle” that told them they did!
sdmi academics part 2
SDMI & Academics: Part 2
  • Academics couldn’t claim cash prize
    • Doing so would have required signing a “confidentiality agreement” and prohibit the academics from sharing results with the public
  • DMCA didn’t apply…
    • … because SDMI specifically invited the work
  • Felton &c decided to present their findings at the 4th International Information Hiding Workshop April 25-29, 2001
  • April 9, 2001 RIAA Senior VP for Business and Legal Affairs sent Felton letter with veiled DMCA threats
  • April 26, 2001 Felton declines to present paper
  • May 3, 2001 – RIAA and SDMI say they never intended to sue
  • June 6, 2001 – Felton files suit against RIAA asking for a declaratory judgment that they would not be infringing
  • November 28, 2001 – Case dismissed for mootness
Leading provider of watermarking technologies

Plug-ins for Windows, PhotoShop, etc.


Copyright ownership

Image ID

Image content – adult, etc.

tools and references
Tools and References
  • Fabien a. p. penticolas
    • http://www.petitcolas.net/fabien/steganography/
  • Digimarc
  • http://theargon.com/archivess/steganography/
  • Hiding Secrets with Steganography, by Dru Lavigne,
    • http://www.onlamp.com/pub/a/bsd/2003/12/04/FreeBSD_Basics.html
  • http://www.outguess.org
mosa c attack
“Mosaïc attack”
  • Defeat an embedded watermark by chopping up image and serving it in pieces

<nobr><img SRC="kings_chapel_wmk1.jpg’ BORDER="0’ ALT="1/6’ width="116’ height="140"><img SRC="kings_chapel_wmk2.jpg’ BORDER="0’ ALT="2/6’ width="116’ height="140"><img SRC="kings_chapel_wmk3.jpg’ BORDER="0’ ALT="3/6’ width="118’ height="140"></nobr><br><nobr><img SRC="kings_chapel_wmk4.jpg’ BORDER="0’ ALT="4/6’ width="116’ height="140"><img SRC="kings_chapel_wmk5.jpg’ BORDER="0’ ALT="5/6’ width="116’ height="140"><img SRC="kings_chapel_wmk6.jpg’ BORDER="0’ ALT="6/6’ width="118’ height="140"></nobr>

mosa c assembled
Mosaïc assembled
  • Some websites use mosaics to deter casual copying!
  • Hides information in MP3 files during the compression process
  • Takes advantage of the fact that MP3 provides high-quality compression of 11:1
    • Plenty of room for information hiding!
    • Randomly chooses which parts of the Layer III inner loop to modify; makes sure modifications don’t exceed threshold defined by the psycho acoustic model.
  • “Weak but better than the MPEG copyright flag defined in the standard”
  • Defeat by decompressing & recompressing
mp3stego in action
MP3Stego in action


translucent databases

Translucent Databases

(More Wayner Work,

if we have time…)

translucent database
Translucent Database
  • Instead of:
    • INSERT INO purchases values (“bob jones”, 55424, “36”, NOW())
  • Use:
    • INSERT INTO purchases values (MD5(“bob jones”, 55424, “36”, NOW())
td s with redundency
TD’s with Redundency
  • INSERT INTO salaries2 VALUES (MD5(“Fred Smith/1313 Mockingbird Lane/06-01-1960/012-34-5678”), MD5(“Fred Smith/1313 Mockingbird Lane/012-34-5678”), MD5(“Fred Smith/1313 Mockingbird Lane/06-01-1960”), MD5(“Fred Smith//06-01-1960/012-34-5678”), 60000, 5 20)
inserting into multi user table
Inserting into multi-user table
  • INSERT INTO bboard1 Values(MD5(“Lucy”),MD5(“Ricky”),”You’ve got some explaining to do.”)
  • INSERT INTO bboard1 Values(MD5(“Lucy”),MD5(“Ricky”),ENCRYPT(”You’ve got some explaining to do.”))