cryptography

cryptography
Public domain · source
Name	Cryptography
Type	Field

cryptography Cryptography is the practice and study of techniques for securing information and enabling confidential communication between parties. It underpins modern National Security Agency operations, informs International Telecommunication Union standards, and shapes technologies deployed by Google, Microsoft, Apple Inc., and Amazon (company). Practitioners draw on research from institutions such as Massachusetts Institute of Technology, Stanford University, University of Cambridge, and École Polytechnique to design systems used by International Organization for Standardization, Internet Engineering Task Force, and companies like RSA Security.

History

Historical roots trace to ancient states and figures including Roman Empire, Egypt, Julius Caesar, and the use of substitution ciphers in the Greco-Roman world. Medieval developments occurred in courts of Ottoman Empire, Abbasid Caliphate, and during exchanges involving Marco Polo; later milestones involved individuals such as Blaise de Vigenère, Thomas Jefferson, and institutions like Royal Society. The telegraph and submarine cable era involved actors including Western Union and events such as the Crimean War, while the 20th century saw breakthroughs tied to World War I, World War II, Enigma machine, Alan Turing, the Bletchley Park project, and organizations such as Government Communications Headquarters and Signals Intelligence. Cold War advances engaged KGB, Central Intelligence Agency, and academic centers like Princeton University and University of California, Berkeley. The public-key revolution involved protagonists Whitfield Diffie, Martin Hellman, Ronald Rivest, Adi Shamir, Leonard Adleman, and commercial impacts reached companies such as Bell Labs, IBM, and AT&T.

Principles and Concepts

Core concepts derive from formal models used by scholars at Courant Institute of Mathematical Sciences, Institute for Advanced Study, and École Normale Supérieure. Key notions include secrecy models formulated by Claude Shannon, authentication standards developed through collaborations with National Institute of Standards and Technology, and trust frameworks adopted by World Wide Web Consortium. Cryptographic primitives rely on mathematical structures studied at American Mathematical Society venues and include ideas influenced by work of Edsger W. Dijkstra, John von Neumann, and Kurt Gödel in logical foundations. Security assumptions often reference problems related to entities such as RSA (company) research groups, and complexity classes explored at Carnegie Mellon University and University of Oxford.

Cryptographic Algorithms

Algorithm families include symmetric-key methods exemplified historically by machines like Enigma machine and modern ciphers standardized by National Institute of Standards and Technology; examples implemented by Cisco Systems and Juniper Networks in routers. Public-key systems trace lineage to proposals from Whitfield Diffie and Martin Hellman and to constructions by Ronald Rivest, Adi Shamir, and Leonard Adleman; these are used by protocols maintained by Internet Engineering Task Force and companies like VeriSign. Hash functions and message authentication codes receive scrutiny in competitions hosted by European Union Agency for Cybersecurity and labs at Los Alamos National Laboratory. Post-quantum candidates are being evaluated by communities including National Institute of Standards and Technology, research groups at IBM, Google, Microsoft Research, and universities such as University of Waterloo and ETH Zurich.

Protocols and Applications

Protocols implement cryptographic primitives in deployments by organizations like World Health Organization for data sharing, banks such as JPMorgan Chase and HSBC for transaction security, and platforms run by Facebook, Twitter, and Telegram Messenger LLP. Standards-setting bodies including Internet Engineering Task Force, International Organization for Standardization, and 3GPP codify practices for secure email, virtual private networks, and mobile telephony used by carriers like Verizon Communications and Vodafone Group. Applications span secure voting studied by Harvard University researchers, digital currencies pioneered by developers associated with Bitcoin, and identity frameworks adopted by governments including United Kingdom and Estonia.

Security and Cryptanalysis

Cryptanalysis has historic exemplars at sites such as Bletchley Park and modern research centers like Sandia National Laboratories, Los Alamos National Laboratory, and university labs at University of Cambridge. Attacks have been publicized by academics from University of Illinois Urbana-Champaign, Georgia Institute of Technology, and independent researchers associated with groups such as EFF; vulnerabilities have implicated vendors including RSA Security and Intel. Threat models consider actors like Advanced Persistent Threat groups, state actors exemplified by People's Republic of China operations or Russian Federation signals intelligence, and criminal organizations investigated by Federal Bureau of Investigation and Europol. Defensive techniques are advanced in collaborations between DARPA, European Commission, and private labs at Google and Microsoft Research.

Legal, Ethical, and Policy Issues

Legal frameworks include statutes and cases adjudicated by institutions such as United States Supreme Court, laws like the USA PATRIOT Act, and regulations from bodies such as European Parliament and Council of the European Union. Export controls historically involved agencies like U.S. Department of Commerce and affected companies including Apple Inc. and Microsoft. Ethical debates engage scholars from Oxford University, Harvard University, and think tanks like RAND Corporation over surveillance practices by agencies such as National Security Agency and judicial oversight exemplified by European Court of Human Rights. Policy forums include consultations at United Nations assemblies, standards deliberations at Internet Corporation for Assigned Names and Numbers, and national strategies issued by Government of the United Kingdom and Government of Canada.

Category:Information security