What Every Citizen Should Know About DRM, aka - Public Knowledge

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What Every Citizen Should Know About DRM,a.k.a. “Digital Rights Management”another downstream device (such as a television, avideo recorder, or a computer) unless the devicecontaining the demodulator first re-encodes thecontent using some other copy-protection technology,or else passes it through “robust” (user-inaccessible)channels to another device that can berelied upon to do the re-encoding. 23If the decoder does re-protect the content, itmust do so using one of the approved copy protectiontechnologies that are listed in “Table A” of thebroadcast-flag framework. 24The scheme additionally requires that if a downstreamdevice is capable of understanding contentthat is encoded using one of the Table A technologies,then that downstream device must itselfimplement that Table A technology.Given the relative simplicity of the broadcastflag itself, the mandates relating to other technolo-gies are in fact the main effect of the broadcast-flagapproach. In this sense, the broadcast-flag schemecan be considered primarily to be a meta-standardwhose purpose is to mandate the use of other standards.Thus, to analyze the real effect of the broadcast-flagscheme we must consider the effect ofmandating all of these other technologies. A fullassessment of that effect is beyond the scope of thispaper, but we may be sure that costs associatedwith a broadcast-flag mandate spread out farbeyond the costs of building flag-detectors intoTV-receiver hardware.To understand why this is so, we need to focus onthe two main lessons to be drawn from our examinationof the broadcast-flag proposal. First, considerthe ever-expanding nature ofbroadcast-flag technology mandate. We startwith a simple broadcast-flag label on digital televi-A Case Study of Watermarking:The Secure Digital Music InitiativeOne example of the problems inherent in attemptingto develop a standard watermarking technology forcontent can be found in the experience of the SecureDigital Music Initiative (SDMI), a consortium of companiesfrom the music, consumer electronics, andsoftware industries. SDMI sought to design a marking-basedDRM system for recorded music. Afterchoosing a set of proposed DRM technologies, includingfour watermarking methods, SDMI announced apublic challenge, inviting the public to try to defeatthe proposed technologies.A team of researchers from Princeton Universityand Rice University studied the four watermarkingmethods, and was able to defeat all of them — thatis, to remove each watermark without unacceptablydamaging the audio quality of the content — in lessthan three weeks of work. 27 During this time theresearchers had access to less information than a realwould-be copyright infringer would have had.The researchers were able to defeat each SDMIwatermark technology by first pinning down thenature of the watermark and where in the content itwas hidden, and then by devising a modification tothe content that would target the watermark’s locationand thereby either remove or mask the watermark.As an example, in one of the SDMItechnologies, the watermark consisted of a smallamount of noise added within a certain narrow rangeof musical tones. Having identified this range oftones, the researchers found it easy to isolate andsuppress this noise, thus defeating the watermark.None of the SDMI watermarks required highlyadvanced technology to defeat. The Princeton andRice researchers concluded that current watermarkingtechnology can be defeated by an attacker of evenmoderate technical sophistication. Although we cannotrule out the possibility that a major advance inwatermarking technology will occur, history suggeststhat any purported advance would have to be subjectedto substantial public scrutiny and testingbefore it could be deemed reliable.15
II. What Does DRM Look Like?sion broadcasts. To protect the effectiveness of this,we need a mandate on all demodulator-containingdevices. But this is pointless unless we impose additionalmandates on all of the devices that might be“downstream” 25 from the demodulator. Becausethere are so many types of downstream devices, wemust incorporate by reference a set of othercopy-protection technologies. What started outas a “simple” broadcast flag scheme ends up includinga range of copy-protection technologies, andwhat started out applying only to digital televisiondemodulators must, to have any hope of even beingeffective at all, up applying to virtually all digitalvideo equipment, personal computers, and personal-computersoftware. 26This expanding-mandatephenomenon is to beWatermarking, like otherexpected with “marking”labeling approaches to approaches generally. Anytechnology mandate coverscontent protection, a limited set of devices andsituations, and the devicesrequires device-makers to at the edge of this coveragetend to become loopholesthrough which theredesign their products.content can escape. Thenatural response is towiden the coverage area to address the loopholes -but this tends only to moves the boundary ratherthan eliminating it.Arguably, then, the only mandate that mightclaim to be truly effective is one that expands toreach the entire universe of digital devices—ineffect, it requires a massive universal redesign of digitaltechnologies that might be used to capture, copy,and redistribute content labeled by the “broadcastflag.” Efforts to “cabin” the effect of the broadcastflagscheme by limiting it to certain classes of digitaldevices (digital TV receivers, set-top boxes, and personalvideo recorders, for example) may limit theextent to which IT companies and others must complywith such mandates, but at the price of increasingthe risk that the marking scheme will besidestepped, either by current or future digital toolsthat aren’t covered by the scheme. 28 This developmentwould render a “cabined” mandate and relatedexpenses a relatively useless and costly exercise.The Risk of Premature Deployment of a Watermark-BasedSchemeAs discussed supra, watermarking remains anunsolved area of scientific research and debate,with many fundamental open problems. No completelysatisfactory watermarking techniques haveyet been developed for the audio, video, or textdomains, nor is it certain that a sufficiently secure,robust and invisible marking technology could bedeveloped in the foreseeable future. It would bevery risky, at present, to deploy systems (or to baseregulatory structures) that depend for their securityor viability on the highly speculative assumptionthat a practical watermarking scheme will be ableto be developed. Should an adequate watermarkingtechnique be invented, however, it would likelyplay a role in several aspects of copy protection andenforcement.At least two applications of digital watermarkingtechnology relate to DRM. The first is contentlabeling, in which the content owner aims to identifyprotected material and specify permissible usesand copying restrictions. The second is serialization,which aims to mark material with a uniqueserial number or message that identifies theauthorized end user and thereby provide evidenceof the source of illegal copying.Neither content labeling nor serialization is sufficientby itself to prevent illegal copying, however.Both approaches require that various parts of thecontent distribution process be “trusted” andsecured against unauthorized access. It is theoreticallypossible that a practical system might bebased on either, or both, approaches, but such apractical system would impose certain requirementson device-makers and other industries thatenable the playback of digital content.Systems based exclusively on content labelingrequire that all devices that use restricted materialwill read the label and refuse to act in a mannerthat is contrary to the restrictions encoded in thelabel. Furthermore, each system component mustcontain all the necessary keys to access the protectedcontent. In addition, the required trustedsystem components include essentially any enduserequipment that must process labeled content.This last requirement is an ambitious one, since it16
Page 1 and 2: What Every CitizenShould Know About
Page 3 and 4: AcknowledgementsThis “DRM primer
Page 5 and 6: I. A Brief Introduction To DRMand i
Page 7 and 8: What Every Citizen Should Know Abou
Page 11 and 12: II. What Does DRM Look Like?system
Page 13 and 14: II. What Does DRM Look Like?The “
Page 15 and 16: II. What Does DRM Look Like?The “
Page 17: II. What Does DRM Look Like?support
Page 21 and 22: II. What Does DRM Look Like?ing tel
Page 23 and 24: III. Should DRM Be ImposedBy the Go
Page 25 and 26: III. Should DRM Be ImposedBy the Go
Page 27 and 28: IV. The “Threat Model” of Unive
Page 33 and 34: V. Conclusion: Can ThereBe a “Hum

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