Table Of ContentC ’
RYPTOGRAPHY S
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Kenneth W. Dam and Herbert S. Lin, Editors
Committee to Study National Cryptography Policy
Computer Science and Telecommunications Board
Commission on Physical Sciences, Mathematics, and Applications
National Research Council
NATIONAL ACADEMY PRESS
Washington, D.C. 1996
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COMMITTEE TO STUDY
NATIONAL CRYPTOGRAPHY POLICY
KENNETH W. DAM, University of Chicago Law School, Chair
W.Y. SMITH, Institute for Defense Analyses (retired), Vice Chair
LEE BOLLINGER, Dartmouth College
ANN CARACRISTI, National Security Agency (retired)
BENJAMIN R. CIVILETTI, Venable, Baetjer, Howard and Civiletti
COLIN CROOK, Citicorp
SAMUEL H. FULLER, Digital Equipment Corporation
LESLIE H. GELB, Council on Foreign Relations
RONALD GRAHAM, AT&T Bell Laboratories
MARTIN HELLMAN, Stanford University
JULIUS L. KATZ, Hills & Company
PETER G. NEUMANN, SRI International
RAYMOND OZZIE, Iris Associates
EDWARD C. SCHMULTS, General Telephone and Electronics (retired)
ELLIOT M. STONE, Massachusetts Health Data Consortium
WILLIS H. WARE, RAND Corporation
Staff
MARJORY S. BLUMENTHAL, Director
HERBERT S. LIN, Study Director and Senior Staff Officer
JOHN M. GODFREY, Research Associate
FRANK PITTELLI, Consultant to CSTB
GAIL E. PRITCHARD, Project Assistant
iii
COMPUTER SCIENCE AND TELECOMMUNICATIONS BOARD
WILLIAM A. WULF, University of Virginia, Chair
FRANCES E. ALLEN, IBM T.J. Watson Research Center
DAVID D. CLARK, Massachusetts Institute of Technology
JEFF DOZIER, University of California at Santa Barbara
HENRY FUCHS, University of North Carolina
CHARLES GESCHKE, Adobe Systems Incorporated
JAMES GRAY, Microsoft Corporation
BARBARA GROSZ, Harvard University
JURIS HARTMANIS, Cornell University
DEBORAH A. JOSEPH, University of Wisconsin
BUTLER W. LAMPSON, Microsoft Corporation
BARBARA LISKOV, Massachusetts Institute of Technology
JOHN MAJOR, Motorola
ROBERT L. MARTIN, AT&T Network Systems
DAVID G. MESSERSCHMITT, University of California at Berkeley
WILLIAM PRESS, Harvard University
CHARLES L. SEITZ, Myricom Incorporated
EDWARD SHORTLIFFE, Stanford University School of Medicine
CASIMIR S. SKRZYPCZAK, NYNEX Corporation
LESLIE L. VADASZ, Intel Corporation
MARJORY S. BLUMENTHAL, Director
HERBERT S. LIN, Senior Staff Officer
PAUL D. SEMENZA, Staff Officer
JERRY R. SHEEHAN, Staff Officer
JEAN E. SMITH, Program Associate
JOHN M. GODFREY, Research Associate
LESLIE M. WADE, Research Assistant
GLORIA P. BEMAH, Administrative Assistant
GAIL E. PRITCHARD, Project Assistant
iv
COMMISSION ON PHYSICAL SCIENCES,
MATHEMATICS, AND APPLICATIONS
ROBERT J. HERMANN, United Technologies Corporation, Chair
PETER M. BANKS, Environmental Research Institute of Michigan
SYLVIA T. CEYER, Massachusetts Institute of Technology
L. LOUIS HEGEDUS, Elf Atochem North America Inc.
JOHN E. HOPCROFT, Cornell University
RHONDA J. HUGHES, Bryn Mawr College
SHIRLEY A. JACKSON, U.S. Nuclear Regulatory Commission
KENNETH I. KELLERMANN, National Radio Astronomy Observatory
KEN KENNEDY, Rice University
THOMAS A. PRINCE, California Institute of Technology
JEROME SACKS, National Institute of Statistical Sciences
L.E. SCRIVEN, University of Minnesota
LEON T. SILVER, California Institute of Technology
CHARLES P. SLICHTER, University of Illinois at Urbana-Champaign
ALVIN W. TRIVELPIECE, Oak Ridge National Laboratory
SHMUEL WINOGRAD, IBM T.J. Watson Research Center
CHARLES A. ZRAKET, MITRE Corporation (retired)
NORMAN METZGER, Executive Director
v
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vi
Preface
INTRODUCTION
For most of history, cryptography—the art and science of secret writ-
ing—has belonged to governments concerned about protecting their own
secrets and about asserting their prerogatives for access to information
relevant to national security and public safety. In the United States, cryp-
tography policy has reflected the U.S. government’s needs for effective
cryptographic protection of classified and other sensitive communica-
tions as well as its needs to gather intelligence for national security pur-
poses, needs that would be damaged by the widespread use of cryptogra-
phy. National security concerns have motivated such actions as
development of cryptographic technologies, development of countermea-
sures to reverse the effects of encryption, and control of cryptographic
technologies for export.
In the last 20 years, a number of developments have brought about
what could be called the popularization of cryptography. First, some
industries—notably financial services—have come to rely on encryption
as an enabler of secure electronic funds transfers. Second, other indus-
tries have developed an interest in encryption for protection of propri-
etary and other sensitive information. Third, the broadening use of
computers and computer networks has generalized the demand for tech-
nologies to secure communications down to the level of individual citi-
zens and assure the privacy and security of their electronic records and
transmissions. Fourth, the sharply increased use of wireless communica-
tions (e.g., cellular telephones) has highlighted the greater vulnerability
vii
vviiiiii CPORNETFEANCTES
of such communications to unauthorized intercept as well as the diffi-
culty of detecting these intercepts.
As a result, efforts have increased to develop encryption systems for
private sector use and to integrate encryption with other information
technology products. Interest has grown in the commercial market for
cryptographic technologies and systems incorporating such technologies,
and the nation has witnessed a heightened debate over individual need
for and access to technologies to protect individual privacy.
Still another consequence of the expectation of widespread use of
encryption is the emergence of law enforcement concerns that parallel, on
a civilian basis, some of the national security concerns. Law enforcement
officials fear that wide dissemination of effective cryptographic technolo-
gies will impede their efforts to collect information necessary for pursu-
ing criminal investigations. On the other side, civil libertarians fear that
controls on cryptographic technologies will give government authorities
both in the United States and abroad unprecedented and unwarranted
capabilities for intrusion into the private lives of citizens.
CHARGE OF THE COMMITTEE TO STUDY
NATIONAL CRYPTOGRAPHY POLICY
At the request of the U.S. Congress in November 1993, the National
Research Council’s Computer Science and Telecommunications Board
(CSTB) formed the Committee to Study National Cryptography Policy.
In accordance with its legislative charge (Box P.1), the committee under-
took the following tasks:
• Framing the problem. What are the technology trends with which
national cryptography policy must keep pace? What is the political envi-
ronment? What are the significant changes in the post-Cold War environ-
ment that call attention to the need for, and should have an impact on,
cryptography policy?
• Understanding the underlying technology issues and their expected devel-
opment and impact on policy over time. What is and is not possible with
current cryptographic (and related) technologies? How could these ca-
pabilities have an impact on various U.S. interests?
• Describing current cryptography policy. To the committee’s knowl-
edge, there is no single document, classified or unclassified, within the
U.S. government that fully describes national cryptography policy.
• Articulating a framework for thinking about cryptography policy. The
interests affected by national cryptography policy are multiple, varied,
and related: they include personal liberties and constitutional rights, the
maintenance of public order and national security, technology develop-
CPROENFTAECNETS iixx
BOX P.1
Legislative Charge to the National Research Council
Public Law 103-160
Defense Authorization Bill for Fiscal Year 1994
Signed November 30, 1993
SEC. 267. COMPREHENSIVE INDEPENDENT STUDY OF NATIONAL
CRYPTOGRAPHY POLICY.
(a) Study by National Research Council.—Not later than 90 days after the date
of the enactment of this Act, the Secretary of Defense shall request the National
Research Council of the National Academy of Sciences to conduct a comprehensive
study of cryptographic technologies and national cryptography policy.
(b) Matters To Be Assessed in Study.—The study shall assess—
(1) the effect of cryptographic technologies on—
(A) national security interests of the United States Government;
(B) law enforcement interests of the United States Government;
(C) commercial interests of United States industry; and
(D) privacy interests of United States citizens; and
(2) the effect on commercial interests of United States industry of export con-
trols on cryptographic technologies.
(c) Interagency Cooperation With Study.—The Secretary of Defense shall direct
the National Security Agency, the Advanced Research Projects Agency, and other
appropriate agencies of the Department of Defense to cooperate fully with the Na-
tional Research Council in its activities in carrying out the study under this section.
The Secretary shall request all other appropriate Federal departments and agencies to
provide similar cooperation to the National Research Council.
ment, and U.S. economic competitiveness and markets. At a minimum,
policy makers (and their critics) must understand how these interests
interrelate, although they may decide that one particular policy configu-
ration better serves the overall national interest than does another.
• Identifying a range of feasible policy options. The debate over cryptog-
raphy policy has been hampered by an incomplete analysis and discus-
sion of various policy options—both proponents of current policy and of
alternative policies are forced into debating positions in which it is diffi-
cult or impossible to acknowledge that a competing view might have
some merit. This report attempts to discuss fairly the pros and cons of a
number of options.
• Making recommendations regarding cryptography policy. No cryptog-
raphy policy will be stable for all time. That is, it is unrealistic to imagine
xx CPORNETFEANCTES
that this committee or any set of policy makers could craft a policy that
would not have to evolve over time as the technological and political
milieu itself changes. Thus, the committee’s recommendations are framed
in the context of a transition, from a world characterized by slowly evolv-
ing technology, well-defined enemies, and unquestioned U.S. technologi-
cal, economic, and geopolitical dominance to one characterized by rap-
idly evolving technology, fuzzy lines between friend and foe, and
increasing technological, economic, and political interdependencies be-
tween the United States and other nations of the world.
Given the diverse applications of cryptography, national cryptography
policy involves a very large number of important issues. Important to
national cryptography policy as well are issues related to the deployment
of a large-scale infrastructure for cryptography and legislation and regula-
tions to support the widespread use of cryptography for authentication and
data integrity purposes (i.e., collateral applications of cryptography), even
though these issues have not taken center stage in the policy debate.
The committee focused its efforts primarily on issues related to cryp-
tography for confidentiality, because the contentious problem that this
committee was assembled to address at the center of the public policy
debate relates to the use of cryptography in confidentiality applications.
It also addressed issues of cryptography policy related to authentication
and data integrity at a relatively high level, casting its findings and rec-
ommendations in these areas in fairly general terms. However, it notes
that detailed consideration of issues and policy options in these collateral
areas requires additional study at a level of detail and thoroughness com-
parable to that of this report.
In preparing this report, the committee reviewed and synthesized
relevant material from recent reports, took written and oral testimony
from government, industry, and private individuals, reached out exten-
sively to the affected stakeholders to solicit input, and met seven times to
discuss the input from these sources as well as the independent observa-
tions and findings of the committee members themselves. In addition,
this study built upon three prior efforts to examine national cryptography
policy: the Association for Computing Machinery report Codes, Keys, and
Conflicts: Issues in U.S. Crypto Policy,1 the Office of Technology Assess-
ment report Information Security and Privacy in Network Environments,2 and
1Susan Landau et al., Codes, Keys, and Conflicts: Issues in U.S. Crypto Policy, Association
for Computing Machinery Inc., New York, 1994.
2Office of Technology Assessment, Information Security and Privacy in Network Environ-
ments, OTA-TCT-606, U.S. Government Printing Office, Washington, D.C., September 1994.
