On the Incommensurability of Laws and Technical Mechanisms: Or, What Cryptography Can’t Do

  • Joan FeigenbaumEmail author
  • Daniel J. Weitzner
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 11286)


We examine several technology-policy debates in which technical and legal perspectives are so at odds that they approach incommensurability. Investigating the use of digital rights management systems in the online-copyright debate and the dispute over the impact of end-to-end encryption on lawful surveillance, we offer an analysis of the source of this incommensurability. In these two policy debates, both sides invoke the rule of law to support their position, but in each case they draw selectively from the constituent parts of the rule of law, resulting in seemingly irreconcilable differences. We show that the rule of law is actually composed of rules (susceptible to deterministic evaluation against a set of facts) and principles (expressing important values but not susceptible to purely formal evaluation). The clash between rules and principles exacerbates the difference in perspective between system designers, who favor formal rules, and policy makers, who are more comfortable with situational application of principles. Following our observation that the rules-principles gap makes for incommensurate debate between legal and technical actors, we identify steps that each discipline can take to move toward more coherent policy for the networked, digital environment.



Feigenbaum was supported in part by US National Science Foundation grants CNS-1407454 and CNS-1409599 and by the William and Flora Hewlett Foundation grant 2016-3834. Weitzner was supported in part by the William and Flora Hewlett Foundation grant 2014-1601.


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Copyright information

© Springer Nature Switzerland AG 2018

Authors and Affiliations

  1. 1.Computer Science DepartmentYale UniversityNew HavenUSA
  2. 2.Internet Policy Research InitiativeMassachusetts Institute of TechnologyCambridgeUSA

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