Transcript Digital Rights Management

Digital Rights Management
Brian P. Bailey
Spring 2006
Announcements
• Bin Yu speaking this coming Friday
• Send me HW4, evaluation results, and
presentation plans via email
– otherwise drop off to Anda Ohlsson (3120)
Presentation Schedule (In order)
• April 28
– Victor and Daniel
– David and Matt
• May 1
– Chris and Jay
– Sid and Anshul
– Michael and Sangjoon
• 15-20 minutes to present your project
Today’s Goals
• Basics of copyright and patent (IP) law
– application of IP law to software
• DRM must balance prevention of copyright
infringement with allowing for fair use
• Examine two existing DRM systems
– MacroVision for VHS tapes
– Apple’s FairPlay technology for ITunes
Basis for U.S. Copyright Law
U.S. Constitution (A1, S8, C8) states:
"Congress shall have power . . . to promote
the progress of science and useful arts,
by securing for limited times to authors
and inventors the exclusive right to their
respective writings and discoveries”
Origins of Copyright
• Trace to introduction of printing press in
England in late 15th century
– control (censor) publication of books
– maintain registry of legal books
• 1710, passed law to protect authors’ works
– prevent another person from re-producing a
book and putting their name on it
Balance Two Competing Goals
• Protect works of an author long enough
so the author can obtain financial reward
• Allow access to promote public discourse
and progress of science and useful arts
U.S. Copyright Law
• Gives exclusive rights for limited time
– reproduce the work, derive new works,
distribute copies, perform or display it publicly
– set at life of author plus 70 years
• Applies to “original works of authorship”
fixed in tangible medium of expression
– literary, dramatic, artistic, musical, pictorial,
architectural, etc. works
Who Can Claim Copyright
• Almost anyone, but many special cases
– e.g., work was produced in a foreign country,
or non-citizen produces work in the U.S.
• Applies as soon as original work is fixed
– no formal registration is required
– employer almost always owns copyrights
• Ownership does not imply copyright
How to Claim Copyright
• Act of publication with notice of copyright
– e.g., “© 2006 Name of Owner”
– give reasonable notice of claim of copyright
• Act of registration of unpublished works
– establishes date of authorship (thus also
recommended for published works)
– register with U.S. Copyright Office
Copyright Does Not Protect:
• Works not fixed in a tangible form
• Ideas, procedures, methods, processes,
systems, principles, discoveries, etc.
• Work composed solely of common
property with no transformative value
Patents
• Gives patent holder exclusive rights to a
disclosed invention for a limited time
– time is currently set at 20 years
• Inventions
– can be products, methods, processes,
apparatus, etc.
– cannot be obvious to a person of ordinary skill
in the respective domain
IP Dilemma of Software
• Copyright argument
– programming is a form of artistic expression
– no two algorithms programmed the same way
• Patent argument
– applications represent software products
– software implements processes or methods
Fair Use
• Legal use of copyrighted works for
education, research, reporting, etc.
– must provide transformative value
• Determined by four factors
– purpose and character of the use
– nature of the copyrighted work
– amount of the copyrighted work used
– effect on market value of copyrighted work
Two Perspectives
• Affirmative perspective
– allows copying in specific circumstances
• Defensive perspective
– defend copyright infringement
Examples of Fair Use
• Citing short passages of a book for a term
paper
• Making a backup copy of a CD for
personal use
• Song parodies
Technology-enabled Infringement
• Unprecedented speed and reach
– beyond what has been previously possible
• Technology enables the circumvention of
the concept of copyright protection
• Combat with DRM and punitive legislation
Digital Rights Management
• Mission: protect rights of digital media
producers while enabling access for fair use
– grant exclusive rights in exchange for disclosure
• Reality: DRM is just protection technology, and
is fast eroding our rights of fair use
– may never be able to reuse parts of any digital
content (documents, film, images, audio, etc.)
– hinders progress of science and the useful arts
Protection Technology
• Any technology designed to prohibit
access to a copyrighted work
– e.g., algorithms for content encryption
• Protects rights of the author, but
– prohibits fair use
– prohibits public access
– never expires
Digital Millennium Copyright Act
• Illegal to develop or distribute any
mechanism to circumvent protections
– e.g., demonstrating weaknesses in encryption
algorithms or posting algorithm to a website
• Education and research on DRM may
become dormant for fear of lawsuits
– allowed only via exceptions to the DMCA
Research Paradox
• Develop more sophisticated methods to
encrypt digital media content
• Erodes our rights to use digital media
MacroVision (1985-)
• Copy protection technique for VHS tapes
• Inserts special signals into the vertical
blanking interval of NTSC protocol
– affects automatic gain control in most VCRs,
but is ignored by most televisions
– difficult to remove from the original signal
• Makes subsequent recordings shake and
have periods of bright and dark frames
Apple’s FairPlay Technology
• DRM for iTunes
– playing, recording, and sharing of files
• Moves beyond “protection only”
– allows media to be shared among devices
– allows others to listen to (but not copy) music
– allows music to be burned to an audio CD,
which loses the DRM protection
How FairPlay Works
• iTunes uses encrypted MP4 audio files
• Acquire decryption key by trying to play song
– player generates a unique ID
– sends this ID to the iTunes server
– if there are fewer than N authorizations in your
account, the server responds with decryption key
• The decryption key itself is encrypted so cannot
be given to another machine
Discussion
• Is FairPlay too lenient, too stringent, or
just about right?
• What is your experience with this DRM?
• What happens if Apple decides to stop
supporting FairPlay?