Cryptanalysis in the context of "Supercomputer"

An intelligence agency is a government agency responsible for the collection, analysis, and exploitation of information in support of law enforcement, national security, military, public safety, and foreign policy objectives.

Means of information gathering are both overt and covert and may include espionage, communication interception, cryptanalysis, cooperation with other institutions, and evaluation of public sources. The assembly and propagation of this information is known as intelligence analysis or intelligence assessment.

Signals intelligence (SIGINT) is the act and field of intelligence-gathering by interception of signals, whether communications between people (communications intelligence—abbreviated to COMINT) or from electronic signals not directly used in communication (electronic intelligence—abbreviated to ELINT). As classified and sensitive information is usually encrypted, signals intelligence may necessarily involve cryptanalysis (to decipher the messages). Traffic analysis—the study of who is signaling to whom and in what quantity—is also used to integrate information, and it may complement cryptanalysis.

A cryptosystem is considered to have information-theoretic security (also called unconditional security) if the system is secure against adversaries with unlimited computing resources and time. In contrast, a system which depends on the computational cost of cryptanalysis to be secure (and thus can be broken by an attack with unlimited computation) is called computationally secure or conditionally secure.

The ACM A. M. Turing Award is an annual prize given by the Association for Computing Machinery (ACM) for contributions of lasting and major technical importance to computer science. It is generally recognized as the highest distinction in the field of computer science and is often referred to as the "Nobel Prize of Computing". As of 2025, 79 people have been awarded the prize, with the most recent recipients being Andrew Barto and Richard S. Sutton, who won in 2024.

The award is named after Alan Turing, also referred as "Father of Computer Science", who was a British mathematician and reader in mathematics at the University of Manchester. Turing is often credited as being the founder of theoretical computer science and artificial intelligence, and a key contributor to the Allied cryptanalysis of the Enigma cipher during World War II. From 2007 to 2013, the award was accompanied by a prize of US$250,000, with financial support provided by Intel and Google. Since 2014, the award has been accompanied by a prize of US$1 million, with financial support provided by Google.

In cryptology, a code is a method used to encrypt a message that operates at the level of meaning; that is, words or phrases are converted into something else. A code might transform "change" into "CVGDK" or "cocktail lounge". The U.S. National Security Agency defined a code as "A substitution cryptosystem in which the plaintext elements are primarily words, phrases, or sentences, and the code equivalents (called "code groups") typically consist of letters or digits (or both) in otherwise meaningless combinations of identical length." A codebook is needed to encrypt, and decrypt the phrases or words.

By contrast, ciphers encrypt messages at the level of individual letters, or small groups of letters, or even, in modern ciphers, individual bits. Messages can be transformed first by a code, and then by a cipher. Such multiple encryption, or "superencryption" aims to make cryptanalysis more difficult.

Colossus was a set of computers developed by British codebreakers in the years 1943–1945 to help in the cryptanalysis of the Lorenz cipher. Colossus used thermionic valves (vacuum tubes) to perform Boolean and counting operations. Colossus is regarded as the world's first programmable, electronic, digital computer (the first electromechanical being Konrad Zuse's Z3 completed in Berlin in 1941), although it was programmed by switches and plugs and not by a stored program.

Colossus was designed by General Post Office (GPO) research telephone engineer Tommy Flowers based on plans developed by mathematician Max Newman at the Government Code and Cypher School at Bletchley Park.