This is the second part in a series of three posts.
…the managed activities necessary: (1) For the long term maintenance of a byte stream (including metadata) sufficient to reproduce a suitable facsimile of the original document and (2) For the continued accessibility of the document contents through time and changing technology.
This definition calls the byte stream a reproduction, suggesting that the digital preservation is of some physical record. However, this is true even for natively digital content because on each instance of accessing that content, a computer copies the byte stream into memory, thereby reproducing it. Regardless, the archive must support accessibility while mitigating the threat of technological change over time.
The Library and Archives Canada (LAC) mandate serves as a good example for examining where TPMs conjoined with current copyright law, cause conflict. The thrust of LAC’s objectives although unique, are not dissimilar to many other archives. In the preamble of the Library and Archives Canada Act it says
WHEREAS it is necessary that
(a) the documentary heritage of Canada be preserved for the benefit of present and future generations;
(b) Canada be served by an institution that is a source of enduring knowledge accessible to all, contributing to the cultural, social and economic advancement of Canada as a free and democratic society;
(c) that institution facilitate in Canada cooperation among the communities involved in the acquisition, preservation and diffusion of knowledge; and
(d) that institution serve as the continuing memory of the government of Canada and its institutions;. . .
Called a “source for enduring knowledge accessible to all,” the act that established LAC is phrased to imply continuing endurance through time (it does not limit the number of future generations). Thus, the archive itself should be capable of offering its holdings to those that would like to examine them. Operating as the source, the archive needs to be capable of enabling people to access its holdings.
LAC should not be prevented the capabilities to fulfil its mandate. Owning rights (e.g. the rights to access TPM-encumbered content) is of little use if LAC doesn’t at least have the capability to carry out its mandate. LAC has little choice but to address content as preserved in our era’s pervasive use of digital media. Indeed, LAC developed a digital preservation policy in which one of the principle tenets includes the
Generation of access and service copies. Originals and preservation masters will be preserved in archival storage, while web-friendly versions will be generated for public use.
The first important element in this statement is that it explicitly calls out the practice of making copies. The second: that it distinguishes between originals, masters for archival storage, and other versions that the public will access. We should keep in mind that the public expects to engage with archival holdings through electronic means, generally the World Wide Web. The archive must make copies not just for the sake of preservation but for use.
Copying is a strategic and technical requirement of TDRs. Indeed, LAC’s digital preservation TDR system requires multiple copies be made. The original, unaltered bit stream that makes up a digital asset, as submitted by the content creator, will always be retained within a LAC TDR as Preservation Master 0. If the original logical file format is at risk of obsolescence, it may be migrated to an alternate format, thus creating another preservation master. All preservation masters exist in multiple copies.
The procedure for preserving digital assets is to take the original, as LAC receives it, and eventually to migrate it to other formats. I use the term “eventually” (though LAC’s policy is written conditionally) because content stored on digital media faces the media’s inevitable obsolescence. Obsolescence occurs because the devices that read the media may no longer be produced, systems that operate with those devices cease to exist, or the formats stored on the media are no longer readable by computer systems.
Migration is the periodic transfer of digital materials from one hardware/software configuration to another, or from one generation of computer technology to a subsequent generation. The purpose of migration is to preserve the integrity of digital objects and to retain the ability for clients to retrieve, display, and otherwise use them in the face of constantly changing technology.
Although the act of migrating is by definition also an act of copying, LAC goes a step further, maintaining all preservation masters (original or not) in multiple copies. These copies are part of TDR strategy as I’ll now explain.
Trusted Digital Repositories
A TDR is an integral part of archival strategy for long term digital preservation. The Research Libraries Group (RLG) defines it thus:
A trusted digital repository is one whose mission is to provide reliable, long-term access to managed digital resources to its designated community, now and in the future.
Trusted digital repositories are designed in principle to have a great deal of redundancy, helping ensure the integrity of what they store. But we still have to worry about the technical components of the TDR. This results from the ungraceful deterioration of digital media as well as from mechanical and natural contingencies.
All of our digital recording media require active management in order to avoid problems due to media degradation and failure. The only approach to this generic problem is for the repository manager to put in place policies for routine backups, off-site backup, and the use of mirrored sites or other types of redundancy options to ensure that there is always another digital “place” where one can find the original object. From a digital preservation perspective, redundancy of content is perhaps the most critical consideration.
Making many copies of the digitally-stored content and continually migrating those to “upgraded” digital storage mediums ensures (hopefully) that the stored content remains accessible on whatever the present-day’s computer systems are.
A TPM that causes an archive to be incapable (technically) of copying content may not be circumvented under current law. I’ve already identified a situation (the professor’s notes example) in which TPM-encumbered content would not be copyable and if it’s not copyable, it’s not migrateable. Such content is thus outside the scope of what archives may properly preserve as holdings in a TDR.
Lets return to considering approaches to long term digital preservation. An archive could acquire all appropriate rights and mechanisms to enable it to access TPM-encumbered content but this is not a practical solution for backup and migration processes. As new technologies, media, or infrastructure techniques are introduced to the market, there is scant likelihood that all TPM techniques will be transferable or continue to work on the necessary computer systems.
If the TPMs are dependent on a third party, which they invariably are, the third party may not continue to be able to provide the accessible rights, nor might it even continue to exist. Companies and their processes come and go. Relying on the existence of third party rights-holders is a folly that will cripple long term preservation strategies.
So long as a trusted digital repository is necessary for digital preservation practices, we must worry about anything that prevents a TDR from achieving its function. While TPMs exist in the marketplace and digital content is encumbered by them, anti-circumvention of TPMs make TDR strategies ineffective.
- Jantz, Ronald and Giarlo, Michael. “Digital Archiving and Preservation: Technologies and Processes for a Trusted Repository.” Journal of Archival Organization 4:1-2 2008: 195. http://dx.doi.org/10.1300/J201v04n01_10 (30 October 2012). †
- Library and Archives of Canada Act. Statutes of Canada. 2004, c 11. †
- Bak, Greg and Armstrong, Pam. “Points of convergence: seamless long-term access to digital publications and archival records at library and archives Canada,” Archival Science Volume 8, Issue 4, (2008) p 283, http://link.springer.com/article/10.1007%2Fs10502-009-9091-4?LI=true (30 October 2012). †
- Bak, Greg and Armstrong, Pam. “Points of convergence: seamless long-term access to digital publications and archival records at library and archives Canada,” Archival Science Volume 8, Issue 4, (2008) p 287, http://link.springer.com/article/10.1007%2Fs10502-009-9091-4?LI=true (30 October 2012). †
- Andre, Pamela Q.C., et al. “Preserving Digital Information Report of the Task Force on Archiving of Digital Information,” The Commission on Preservation and Access and The Research Libraries Group. (1996) p 6, http://www.oclc.org/research/activities/digpresstudy.html (30 October 2012). †
An Act to amend the Copyright Act. Statutes of Canada. 2012, c 20.
Andre, Pamela Q.C., et al. "Preserving Digital Information Report of the Task Force on Archiving of Digital Information," The Commission on Preservation and Access and The Research Libraries Group. (1996). http://www.oclc.org/research/activities/digpresstudy.html (30 October 2012).
Bak, Greg and Armstrong, Pam. "Points of convergence: seamless long-term access to digital publications and archival records at library and archives Canada," Archival Science Volume 8, Issue 4, (2008) pp 279-293, http://link.springer.com/article/10.1007%2Fs10502-009-9091-4?LI=true (30 October 2012).
Beagrie, Neil, et al. "Trusted Digital Repositories: Attributes and Responsibilities," Research Libraries Group. (2002). http://www.oclc.org/research/activities/trustedrep.html (30 October 2012).
"Briefing: Demystifying Technical Protection Measures (TPMs) in the Library." Association of Research Libraries (ARL). 25 January 2012. http://www.arl.org/pp/ppcopyright/codefairuse/demystifying-tpms.shtml (31 October 2012).
Canadian Council of Archives "Guidelines for Appraisal Criteria for Non-Institutional Records" in Building a National Acquisition Strategy. Ottawa. Canadian Council of Archives, p. 53-61.
Jantz, Ronald and Giarlo, Michael. "Digital Archiving and Preservation: Technologies and Processes for a Trusted Repository." Journal of Archival Organization 4:1-2 2008: 193-213. http://dx.doi.org/10.1300/J201v04n01_10 (30 October 2012).
Library and Archives of Canada Act. Statutes of Canada. 2004, c 11.
Ridner, John. From Polders to Postmodernism: A Concise History of Archival Theory. Duluth, Minnesota: Litwin Books, LLC, p.143-161.