Whitfield Diffie is a consulting scholar at CISAC. He was a visiting scholar in 2009-2010 and an affiliate from 2010-2012. He is best known for the discovery of the concept of public key cryptography, in 1975, which he developed along with Stanford University Electrical Engineering Professor Martin Hellman. Public key cryptography, which revolutionized not only cryptography but also the cryptographic community, now underlies the security of internet commerce.

During the 1980s, Diffie served as manager of secure systems research at Northern Telecom. In 1991, he joined Sun Microsystems as distinguished engineer and remained as Sun fellow and chief security officer until the spring of 2009.

Diffie spent the 1990s working to protect the individual and business right to use encryption, for which he argues in the book Privacy on the Line, the Politics of Wiretapping and Encryption, which he wrote jointly with Susan Landau. Diffie is a Marconi fellow and the recipient of a number of awards including the National Computer Systems Security Award (given jointly by NIST and NSA) and the Franklin Institute's Levy Prize.

David Brady is deputy director and senior fellow at the Hoover Institution. He is also the Bowen H. and Janice Arthur McCoy Professor of Political Science and Ethics in the Stanford Graduate School of Business and professor of political science in the School of Humanities and Sciences at the university.

Brady is an expert on the U.S. Congress and congressional decision making. His current research focuses on the political history of the U.S. Congress, the history of U.S. election results, and public policy processes in general.

His recent publications include, with John Cogan, "Out of Step, Out of Office," American Political Science Review, March 2001; with John Cogan and Morris Fiorina, Change and Continuity in House Elections (Stanford University Press, 2000); Revolving Gridlock: Politics and Policy from Carter to Clinton (Westview Press, 1999); with John Cogan and Doug Rivers, How the Republicans Captured the House: An Assessment of the 1994 Midterm Elections (Hoover Essays in Public Policy, 1995); and The 1996 House Elections: Reaffirming the Conservative Trend (Hoover Essays in Public Policy, 1997). Brady is also author of Congressional Voting in a Partisan Era (University of Kansas Press, 1973) and Critical Elections in the U.S. House of Representatives (Stanford University Press, 1988).

Brady has been on continuing appointment at Stanford University since 1987. He was associate dean from 1997 to 2001 at Stanford University; a fellow at the center for Advanced Study in the Behavioral Sciences from 1985 to 1986 and again in 2001-2; the Autrey Professor at Rice University, 1980-87; and an associate professor and professor at the University of Houston, 1972-79.

In 1995 and 2000 he received the Congressional Quarterly Prize for the "best paper on a legislative topic." In 1992 he received the Dinkelspiel Award for Excellence in Undergraduate Teaching from Stanford University, and in 1993 he received the Phi Beta Kappa Award for best teacher at Stanford University.

Brady taught previously at Rice University, where he was honored with the George Brown Award for Superior Teaching. He also received the Richard F. Fenno Award of the American Political Science Association for the "best book on legislative studies" published in 1988-89.

He is a member of the American Academy of Arts and Sciences.

Brady received a B.S. degree from Western Illinois University and an M.A. in 1967 and a Ph.D. in 1970 from the University of Iowa. He was a C.I.C. scholar at the University of Michigan from 1964 to 1965.

Scott D. Sagan is the Caroline S.G. Munro Professor of Political Science, the Bass University Fellow in Undergraduate Education, and a Senior Fellow at the Center for International Security and Cooperation, where he previously served as the social science co-director. He is the Inaugural Harry Frank Guggenheim Fellow for Nuclear Ethics and Security at the Carnegie Council for Ethics in International Affairs (2026-2027). Sagan also serves as co-chair of the American Academy of Arts and Sciences’ Committee on International Security Studies. Before joining the Stanford faculty, he was a lecturer in the Department of Government at Harvard University and served as special assistant to the director of the Organization of the Joint Chiefs of Staff in the Pentagon.

Sagan is the author of Moving Targets: Nuclear Strategy and National Security (Princeton University Press, 1989); The Limits of Safety: Organizations, Accidents, and Nuclear Weapons (Princeton University Press, 1993); and, with co-author Kenneth N. Waltz, The Spread of Nuclear Weapons: An Enduring Debate (W.W. Norton, 2012). He is the co-editor of Insider Threats (Cornell University Press, 2017) with Matthew Bunn; and co-editor of The Fragile Balance of Terror (Cornell University Press, 2022) with Vipin Narang. Sagan was also the guest editor of a two-volume special issue of Daedalus: Ethics, Technology, and War (Fall 2016) and The Changing Rules of War (Winter 2017).

Recent publications include “Creeds and Contestation: How US Nuclear and Legal Doctrine Influence Each Other,” with Janina Dill, in a special issue of Security Studies (December 2025); “Kettles of Hawks: Public Opinion on the Nuclear Taboo and Noncombatant Immunity in the United States, United Kingdom, France, and Israel”, with Janina Dill and Benjamin A. Valentino in Security Studies (February 2022); “The Rule of Law and the Role of Strategy in U.S. Nuclear Doctrine” with Allen S. Weiner in International Security (Spring 2021); “Does the Noncombatant Immunity Norm Have Stopping Power?” with Benjamin A. Valentino in International Security (Fall 2020); and “Just War and Unjust Soldiers: American Public Opinion on the Moral Equality of Combatants” and “On Reciprocity, Revenge, and Replication: A Rejoinder to Walzer, McMahan, and Keohane” with Benjamin A. Valentino in Ethics & International Affairs (Winter 2019).

In 2022, Sagan was awarded Thérèse Delpech Memorial Award from the Carnegie Endowment for International Peace at their International Nuclear Policy Conference. In 2017, he received the International Studies Association’s Susan Strange Award which recognizes the scholar whose “singular intellect, assertiveness, and insight most challenge conventional wisdom and intellectual and organizational complacency" in the international studies community. Sagan was also the recipient of the National Academy of Sciences William and Katherine Estes Award in 2015, for his work addressing the risks of nuclear weapons and the causes of nuclear proliferation. The award, which is granted triennially, recognizes “research in any field of cognitive or behavioral science that advances understanding of issues relating to the risk of nuclear war.” In 2013, Sagan received the International Studies Association's International Security Studies Section Distinguished Scholar Award. He has also won four teaching awards: Stanford’s 1998-99 Dean’s Award for Distinguished Teaching; Stanford's 1996 Hoagland Prize for Undergraduate Teaching; the International Studies Association’s 2008 Innovative Teaching Award; and the Monterey Institute for International Studies’ Nonproliferation Education Award in 2009.