Timeline of information theory

• 1872 – Ludwig Boltzmann presents his H-theorem, and with it the formula Σp_i log p_i for the entropy of a single gas particle
• 1878 – J. Willard Gibbs defines the Gibbs entropy: the probabilities in the entropy formula are now taken as probabilities of the state of the whole system
• 1924 – Harry Nyquist discusses quantifying "intelligence" and the speed at which it can be transmitted by a communication system
• 1927 – John von Neumann defines the von Neumann entropy, extending the Gibbs entropy to quantum mechanics
• 1928 – Ralph Hartley introduces Hartley information as the logarithm of the number of possible messages, with information being communicated when the receiver can distinguish one sequence of symbols from any other
• 1929 – Leó Szilárd analyses Maxwell's Demon, showing how a Szilard engine can sometimes transform information into the extraction of useful work
• 1940 – Alan Turing introduces the deciban as a measure of information inferred about the German Enigma machine cypher settings by the Banburismus process
• 1944 – Claude Shannon's theory of information is substantially complete
• 1947 – Richard W. Hamming invents Hamming codes for error detection and correction
• 1948 – Claude E. Shannon publishes A Mathematical Theory of Communication
• 1949 – Claude E. Shannon publishes Communication in the Presence of Noise – Nyquist–Shannon sampling theorem and Shannon–Hartley law
• 1949 – Claude E. Shannon's Communication Theory of Secrecy Systems is declassified
• 1949 – Robert M. Fano publishes Transmission of Information. M.I.T. Press, Cambridge, Massachusetts – Shannon–Fano coding
• 1949 – Leon G. Kraft discovers Kraft's inequality, which shows the limits of prefix codes
• 1949 – Marcel J. E. Golay introduces Golay codes for forward error correction
• 1951 – Solomon Kullback and Richard Leibler introduce the Kullback–Leibler divergence
• 1951 – David A. Huffman invents Huffman encoding, a method of finding optimal prefix codes for lossless data compression
• 1953 – August Albert Sardinas and George W. Patterson devise the Sardinas–Patterson algorithm, a procedure to decide whether a given variable-length code is uniquely decodable
• 1954 – Irving S. Reed and David E. Muller propose Reed–Muller codes
• 1955 – Peter Elias introduces convolutional codes
• 1957 – Eugene Prange first discusses cyclic codes
• 1959 – Alexis Hocquenghem, and independently the next year Raj Chandra Bose and Dwijendra Kumar Ray-Chaudhuri, discover BCH codes
• 1960 – Irving S. Reed and Gustave Solomon propose Reed–Solomon codes
• 1962 – Robert G. Gallager proposes low-density parity-check codes; they are unused for 30 years due to technical limitations
• 1965 – Dave Forney discusses concatenated codes
• 1966 – Fumitada Itakura and Shuzo Saito develop linear predictive coding, a form of speech coding
• 1967 – Andrew Viterbi reveals the Viterbi algorithm, making decoding of convolutional codes practicable
• 1968 – Elwyn Berlekamp invents the Berlekamp–Massey algorithm; its application to decoding BCH and Reed–Solomon codes is pointed out by James L. Massey the following year
• 1968 – Chris Wallace and David M. Boulton publish the first of many papers on Minimum Message Length statistical and inductive inference
• 1970 – Valerii Denisovich Goppa introduces Goppa codes
• 1972 – Jørn Justesen proposes Justesen codes, an improvement of Reed–Solomon codes
• 1972 – Nasir Ahmed proposes the discrete cosine transform, which he develops with T. Natarajan and K. R. Rao in 1973; the DCT later became the most widely used lossy compression algorithm, the basis for multimedia formats such as JPEG, MPEG and MP3
• 1973 – David Slepian and Jack Wolf discover and prove the Slepian–Wolf coding limits for distributed source coding
• 1976 – Gottfried Ungerboeck gives the first paper on trellis modulation; a more detailed exposition in 1982 leads to a raising of analogue modem POTS speeds from 9.6 kbit/s to 33.6 kbit/s
• 1976 – Richard Pasco and Jorma J. Rissanen develop effective arithmetic coding techniques
• 1977 – Abraham Lempel and Jacob Ziv develop Lempel–Ziv compression
• 1989 – Phil Katz publishes the .zip format including DEFLATE ; later to become the most widely used archive container
• 1993 – Claude Berrou, Alain Glavieux and Punya Thitimajshima introduce Turbo codes
• 1994 – Michael Burrows and David Wheeler publish the Burrows–Wheeler transform, later to find use in bzip2
• 1995 – Benjamin Schumacher coins the term qubit and proves the quantum noiseless coding theorem
• 2006 – first Asymmetric numeral systems entropy coding: since 2014 popular replacement of Huffman and arithmetic coding in compressors like Facebook Zstandard or Apple LZFSE
• 2008 – Erdal Arıkan introduces polar codes, the first practical construction of codes that achieves capacity for a wide array of channels