version of secure content-distribution software to newer versions) is certainly possible, but one has to worry about whether software with these capabilities will be made available in a competitive marketplace without a legal requirement.
Existing technical protection services do not, as far as the committee has been able to determine, include an express "self-destruct" mechanism triggered when the copyright on a work expires and it finally enters the public domain. The design of such a mechanism would be tricky, because this date is set at life of the author plus a fixed number of years (or at publication plus a fixed number of years for works of corporate authorship). In the former case, the protection software would in principle have to be able to determine when the author died in order to decide when to cease operating.54 One can envision situations in which works in the public domain remain entangled with protection software that still attempts to limit access to the work. This largely unforeseen consequence of the recent legislative endorsement of technical protection services may, in the long term, run counter to the public good of a healthy and accessible public domain (Lynch, 1997). An assessment is needed to consider whether the requirements for disengagement of a TPS should be part of the legal and social constraints on the deployment of such protection services in the first place.
Although the focus here has been on the potential difficulties raised by technical protection services, they can also have a positive effect on archiving. For example, the lack of effective TPSs may cause content owners to avoid making their works available to the public in digital formats in the first place. This lack of availability could have serious implications for the public good. The committee acknowledges that the foregoing discussion of archiving and TPSs presumes the existence of works and focuses on the issues for archival institutions and archiving processes. Clearly, authors and publishers need to have appropriate incentives and protections so that they create and distribute content in the first place.
54The details of authorship are part of the copyright management information protected under the DMCA. Formally recording this information may ease the transition of works into the public domain on several levels, First, it may make determining when a work enters the public domain less costly, and second, it may make automatically disengaging technical protection feasible.