Lars Ramkilde Knudsen (born 21 February 1962) is a

Danish Danish may refer to: * Something of, from, or related to the country of Denmark People * A national or citizen of Denmark, also called a "Dane," see Demographics of Denmark * Culture of Denmark * Danish people or Danes, people with a Danish a ...

researcher in

cryptography Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or ''-logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adver ...

, particularly interested in the design and

analysis Analysis ( : analyses) is the process of breaking a complex topic or substance into smaller parts in order to gain a better understanding of it. The technique has been applied in the study of mathematics and logic since before Aristotle (38 ...

block cipher In cryptography, a block cipher is a deterministic algorithm operating on fixed-length groups of bits, called ''blocks''. Block ciphers are specified cryptographic primitive, elementary components in the design of many cryptographic protocols and ...

hash functions A hash function is any function that can be used to map data of arbitrary size to fixed-size values. The values returned by a hash function are called ''hash values'', ''hash codes'', ''digests'', or simply ''hashes''. The values are usually u ...

and

message authentication code In cryptography, a message authentication code (MAC), sometimes known as a ''tag'', is a short piece of information used for authenticating a message. In other words, to confirm that the message came from the stated sender (its authenticity) and ...

s (MACs).

Academic

After some early work in

banking A bank is a financial institution that accepts deposits from the public and creates a demand deposit while simultaneously making loans. Lending activities can be directly performed by the bank or indirectly through capital markets. Because ...

, Knudsen enrolled at

Aarhus University Aarhus University ( da, Aarhus Universitet, abbreviated AU) is a public research university with its main campus located in Aarhus, Denmark. It is the second largest and second oldest university in Denmark. The university is part of the Coimbra Gr ...

in 1984 studying

mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...

and

computer science Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to Applied science, practical discipli ...

, gaining an MSc in 1992 and a PhD in 1994. From 1997-2001, he worked at the

University of Bergen The University of Bergen ( no, Universitetet i Bergen, ) is a research-intensive state university located in Bergen, Norway. As of 2019, the university has over 4,000 employees and 18,000 students. It was established by an act of parliament in 194 ...

Norway Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and t ...

. Currently, Knudsen is a professor in the Department of

Mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...

at the

Technical University of Denmark The Technical University of Denmark ( da, Danmarks Tekniske Universitet), often simply referred to as DTU, is a polytechnic university and school of engineering. It was founded in 1829 at the initiative of Hans Christian Ørsted as Denmark's fi ...

Ivan Damgård Ivan Bjerre Damgård (born 1956) is a Danish cryptographer and currently a professor at the Department of Computer Science, Aarhus University, Denmark. Academic background In 1983, he obtained a master's degree in mathematics (with minors in ...

was Lars' mentor during his studies at Aarhus University. His Ph.D. was refereed by

Bart Preneel Bart Preneel (born 15 October 1963 in Leuven, Belgium) is a Flemish cryptographer and cryptanalyst. He is a professor at Katholieke Universiteit Leuven, in the COSIC group. He was the president of the International Association for Cryptologic R ...

Publications

Knudsen has published a couple of papers on cryptanalysis of cryptographic primitives, including the R-MAC scheme, the

SHA-1 In cryptography, SHA-1 (Secure Hash Algorithm 1) is a cryptographically broken but still widely used hash function which takes an input and produces a 160-bit (20-byte) hash value known as a message digest – typically rendered as 40 hexadecima ...

and MD2 hash functions, and a couple of block

cipher In cryptography, a cipher (or cypher) is an algorithm for performing encryption or decryption—a series of well-defined steps that can be followed as a procedure. An alternative, less common term is ''encipherment''. To encipher or encode i ...

DES Des is a masculine given name, mostly a short form (hypocorism) of Desmond. People named Des include: People * Des Buckingham, English football manager * Des Corcoran, (1928–2004), Australian politician * Des Dillon (disambiguation), sever ...

, DFC,

IDEA In common usage and in philosophy, ideas are the results of thought. Also in philosophy, ideas can also be mental representational images of some object. Many philosophers have considered ideas to be a fundamental ontological category of being ...

ICE Ice is water frozen into a solid state, typically forming at or below temperatures of 0 degrees Celsius or Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaq ...

LOKI Loki is a god in Norse mythology. According to some sources, Loki is the son of Fárbauti (a jötunn) and Laufey (mentioned as a goddess), and the brother of Helblindi and Býleistr. Loki is married to Sigyn and they have two sons, Narfi or Na ...

MISTY Misty may refer to: Music * ''Misty'' (Ray Stevens album), an album by Ray Stevens featuring the above song * ''Misty'' (Richard "Groove" Holmes album), an album by Richard "Groove" Holmes featuring the above song * ''Misty'' (Eddie "Lockjaw" ...

RC2 In cryptography, RC2 (also known as ARC2) is a symmetric-key block cipher designed by Ron Rivest in 1987. "RC" stands for "Ron's Code" or "Rivest Cipher"; other ciphers designed by Rivest include RC4, RC5, and RC6. The development of RC2 wa ...

, RC5,

RC6 In cryptography, RC6 (Rivest cipher 6) is a symmetric key block cipher derived from RC5. It was designed by Ron Rivest, Matt Robshaw, Ray Sidney, and Yiqun Lisa Yin to meet the requirements of the Advanced Encryption Standard (AES) competition. ...

SC2000 In cryptography, SC2000 is a block cipher invented by a research group at Fujitsu Labs. It was submitted to the NESSIE project, but was not selected. It was among the cryptographic techniques recommended for Japanese government use by CRYPTR ...

, Skipjack,

Square In Euclidean geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90-degree angles, π/2 radian angles, or right angles). It can also be defined as a rectangle with two equal-length adj ...

and

SAFER In cryptography, SAFER (Secure And Fast Encryption Routine) is the name of a family of block ciphers designed primarily by James Massey (one of the designers of IDEA) on behalf of Cylink Corporation. The early SAFER K and SAFER SK designs share ...

. Knudsen was involved in designing some ciphers:

AES candidate The Advanced Encryption Standard (AES), the symmetric block cipher ratified as a standard by National Institute of Standards and Technology of the United States (NIST), was chosen using a process lasting from 1997 to 2000 that was markedly more ...

DEAL A deal, or deals may refer to: Places United States * Deal, New Jersey, a borough * Deal, Pennsylvania, an unincorporated community * Deal Lake, New Jersey Elsewhere * Deal Island (Tasmania), Australia * Deal, Kent, a town in England * Deal, ...

and

Serpent Serpent or The Serpent may refer to: * Snake, a carnivorous reptile of the suborder Serpentes Mythology and religion * Sea serpent, a monstrous ocean creature * Serpent (symbolism), the snake in religious rites and mythological contexts * Serp ...

(the latter in conjunction with Ross Anderson and

Eli Biham Eli Biham ( he, אלי ביהם) is an Israeli cryptographer and cryptanalyst, currently a professor at the Technion - Israel Institute of Technology Computer Science department. Starting from October 2008 and till 2013, Biham was the dean of t ...

). He was involved in designing

Grøstl Grøstl is a cryptographic hash function submitted to the NIST hash function competition by Praveen Gauravaram, Lars Knudsen, Krystian Matusiewicz, Florian Mendel, Christian Rechberger, Martin Schläffer, and Søren S. Thomsen. Grøstl was chosen ...

, a hash function which was one of the submissions to the NIST SHA-3 competition (it was not the winner). He introduced the technique of

impossible differential cryptanalysis In cryptography, impossible differential cryptanalysis is a form of differential cryptanalysis for block ciphers. While ordinary differential cryptanalysis tracks differences that propagate through the cipher with greater than expected probability, ...

and

integral cryptanalysis In cryptography, integral cryptanalysis is a cryptanalytic attack that is particularly applicable to block ciphers based on substitution–permutation networks. It was originally designed by Lars Knudsen as a dedicated attack against Square, so ...

References

External links

*
Homepage

{{DEFAULTSORT:Knudsen, Lars 1962 births Living people Modern cryptographers Danish scientists Danish computer scientists University of Bergen faculty