Decrypting the
ENCRYPTION DEBATE
A Framework for Decision Makers
Committee on Law Enforcement and Intelligence Access
to Plaintext Information
Computer Science and Telecommunications Board
Division on Engineering and Physical Sciences
A Consensus Study Report of
THE NATIONAL ACADEMIES PRESS
Washington, DC
www.nap.edu
THE NATIONAL ACADEMIES PRESS 500 Fifth Street, NW Washington, DC 20001
This activity was supported by award number 2015-3078 from the William and Flora Hewlett Foundation, award number 15-109219-000-HRS from the John D. and Catherine T. MacArthur Foundation, and award number CNS-1555610 from the National Science Foundation. Any opinions, findings, conclusions, or recommendations expressed in this publication do not necessarily reflect the views of any organization or agency that provided support for the project.
International Standard Book Number-13: 978-0-309-47153-4
International Standard Book Number-10: 0-309-47153-2
Digital Object Identifier: https://doi.org/10.17226/25010
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Copyright 2018 by the National Academy of Sciences. All rights reserved.
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Suggested citation: National Academies of Sciences, Engineering, and Medicine. 2018. Decrypting the Encryption Debate: A Framework for Decision Makers. Washington, DC: The National Academies Press. doi: https://doi.org/10.17266/25010.
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COMMITTEE ON LAW ENFORCEMENT AND INTELLIGENCE ACCESS TO PLAINTEXT INFORMATION
FRED H. CATE, Indiana University, Chair
DAN BONEH, NAE,1 Stanford University
FREDERICK R. CHANG, NAE, Southern Methodist University
SCOTT CHARNEY, Microsoft Corp.
SHAFRIRA GOLDWASSER, NAS2/NAE, Massachusetts Institute of Technology
DAVID A. HOFFMAN, Intel Corporation
SENY KAMARA, Brown University
DAVID KRIS, Culper Partners, LLC
SUSAN LANDAU, Tufts University
STEVEN B. LIPNER, NAE, SAFECode
RICHARD LITTLEHALE, Tennessee Bureau of Investigation
KATE MARTIN, Center for American Progress
HARVEY RISHIKOF, Cybersecurity Legal Task Force, American Bar Association
PETER J. WEINBERGER, Google, Inc.
Staff
JON EISENBERG, Study Director and Senior Director, Computer Science and Telecommunications Board
KATIRIA ORTIZ, Associate Program Officer
SHENAE BRADLEY, Administrative Assistant
JANKI PATEL, Senior Program Assistant
___________________
1 Member, National Academy of Engineering.
2 Member, National Academy of Sciences.
COMPUTER SCIENCE AND TELECOMMUNICATIONS BOARD
FARNAM JAHANIAN, Carnegie Mellon University, Chair
LUIZ ANDRE BARROSO, Google, Inc.
STEVEN BELLOVIN, Columbia University
ROBERT F. BRAMMER, Brammer Technology, LLC
EDWARD FRANK, Cloud Parity, Inc.
LAURA HAAS, University of Massachusetts, Amherst
MARK HOROWITZ, Stanford University
ERIC HORVITZ, Microsoft Research
VIJAY KUMAR, Univ. of Pennsylvania
BETH MYNATT, Georgia Institute of Technology
CRAIG PARTRIDGE, Raytheon BBN Technologies
DANIELA RUS, Massachusetts Institute of Technology
FRED SCHNEIDER, Cornell University
MARGO SELTZER, Harvard University
MOSCHE VARDI, Rice University
KATHERINE YELICK, University of California, Berkeley
Staff
JON EISENBERG, Senior Director
LYNETTE I. MILLETT, Associate Director
SHENAE BRADLEY, Administrative Assistant
EMILY GRUMBLING, Program Officer
RENEE HAWKINS, Financial and Administrative Manager
KATIRIA ORTIZ, Associate Program Officer
JANKI PATEL, Senior Program Assistant
For more information on CSTB, see its Web site at http://www.cstb.org, write to CSTB at National Academies of Sciences, Engineering and Medicine, 500 Fifth Street, NW, Washington, DC 20001, call (202) 334-2605, or email the CSTB at cstb@nas.edu.
Acknowledgment of Reviewers
This Consensus Study Report was reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise. The purpose of this independent review is to provide candid and critical comments that will assist the National Academies of Sciences, Engineering, and Medicine in making each published report as sound as possible and to ensure that it meets the institutional standards for quality, objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process.
We wish to thank the following individuals for their review of this report:
Kevin Bankston, Open Technology Institute,
Alvaro Bedoya, Georgetown University Law School,
James Emerson, iThreat Cyber Group,
Edward W. Felten, NAE,1 Princeton University,
Eric Grosse, EHG Flight, LLC,
Joseph Lorenzo Hall, Center for Democracy and Technology,
Susan Hennessey, Brookings Institution,
John C. (“Chris”) Inglis, U.S. Naval Academy,
Kenn Kern, New York County District Attorney’s Office,
___________________
1 Member, National Academy of Engineering.
Butler W. Lampson, NAS2/NAE, Microsoft Corporation,
Josiah Landers, Rockland County, New York, District Attorney’s Office,
Bruce W. McConnell, EastWest Institute,
Deirdre K. Mulligan, University of California, Berkeley,
Ronald L. Rivest, NAS/NAE, Massachusetts Institute of Technology,
Peter Swire, Georgia Institute of Technology, and
Marcus C. Thomas, Subsentio, LLC.
Although the reviewers listed above provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations of this report nor did they see the final draft before its release. The review of this report was overseen by Robert F. Sproull, NAE, University of Massachusetts, Amherst. He was responsible for making certain that an independent examination of this report was carried out in accordance with the standards of the National Academies and that all review comments were carefully considered. Responsibility for the final content rests entirely with the authoring committee and the National Academies.
___________________
2 Member, National Academy of Sciences.
Preface
Government access to the plaintext of encrypted communications and stored data presents difficult, important, and controversial issues that reveal conflicting values within the government and society at large. The debate over efforts to ensure that access is very polarized. Critics of government access, even as they acknowledge the importance of effective law enforcement, cite legal and practical objections, including risks to security, privacy and civil liberties, and U.S. commercial interests. Government officials acknowledge the value of encryption to protect privacy and confidential information but also express the need to be able to access information relevant to investigations when properly authorized.
To address these issues (Box P.1), the National Academies of Sciences, Engineering, and Medicine appointed the Committee on Law Enforcement and Intelligence Access to Plaintext Information (biosketches in Appendix A). It met four times in person to receive briefings from government, industry, and academic experts (listed in Appendix B) and also used these meetings, supplemented by conference calls and email discussion, to deliberate and develop this report.
To better inform the policy debate and future decision making, this report reviews how encryption is used, including its applications to cybersecurity; its role in protecting privacy and civil liberties; the needs of law enforcement and the intelligence community for information; technical and policy options for accessing plaintext; and the international landscape.
Because the concerns expressed by law enforcement officials at the federal, state, and local levels have been more clearcut and less nuanced
than the views offered by U.S. intelligence officials, who in contrast to law enforcement representatives have not vigorously advocated in public for exceptional access, this report not only gives greater attention to law enforcement needs but also discusses national security needs. The last chapter of the report provides a framework for evaluating policy or technical approaches for government access to plaintext. The committee intends that developing and debating answers to these questions will help illuminate the underlying issues and trade-offs and help guide future decisions about government access to plaintext.
Moreover, while it suspects there will always be disagreements over how to address the challenges presented by encryption, it is the committee’s hope that this report will facilitate a frank conversation, involving all parties, about those challenges and alternative approaches to addressing them. The process of creating this report at times was challenging and required members of the committee to develop a deeper understanding of perspectives with which they did not always agree. But the process was also illuminating, and the committee hopes that the common vocabulary and broad context provided by this report, as well as the analytical framework, will make future conversations easier, more productive, and more likely.
The committee would like to acknowledge the William and Flora Hewlett Foundation, the John D. and Catherine T. MacArthur Foundation, and the National Science Foundation for their generous support for this project and in particular Eli Sugarman (Hewlett Foundation), Eric Sears (MacArthur Foundation), and Jeremy Epstein (National Science
Foundation) for their encouragement and support. It also thanks the National Academies of Sciences, Engineering, and Medicine staff who supported this project: study director Jon Eisenberg, associate program officer Katiria Ortiz, and administrative assistant Shenae Bradley.
Fred H. Cate, Chair
Committee on Law Enforcement and
Intelligence Access to Plaintext Information
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3 THE ROLE OF ENCRYPTION IN PROTECTING PRIVACY AND CIVIL LIBERTIES
4 INFORMATION NEEDS OF LAW ENFORCEMENT AND THE INTELLIGENCE COMMUNITY
Goals of Law Enforcement Officials and Intelligence Analysts
The Volume and Diversity of Information Relevant to Law Enforcement and the Intelligence Community
Encryption as an Impediment to Investigations
The Practical Utility of Alternatives to Exceptional Access
5 OPTIONS FOR ACCESSING PLAINTEXT
Options for Accessing Plaintext
Legal Tools for Obtaining Plaintext within the Current Legislative Framework
Compelled Disclosure of Biometric Identifiers or Passcodes
Compelled Assistance by Third Parties and Related Issues
Legal Aspects of Lawful Hacking
Technological Approaches for Accessing Plaintext, Limitations, and Alternatives
Approaches to Exceptional Plaintext Access
Future Cryptographic Technologies
Ways to Bypass a Plaintext Access Mandate
Alternatives to Exceptional Access
Enhanced Financial and Technical Support
Effects of U.S. Actions on Other Countries and the International Market for U.S. Goods and Services
7 A FRAMEWORK FOR EVALUATING APPROACHES TO ACCESS PLAINTEXT