Kaisa Nyberg
Encyclopedia
Kaisa Nyberg is a cryptographer and computer security
researcher, currently a professor at Helsinki University of Technology
. Her notable work includes the theory of perfect nonlinear S-boxes
(now known as Nyberg S-boxes), provably secure
block cipher
design (resulting in KN-Cipher), and the cryptanalysis
of the stream cipher
s E0
and SNOW
.
Nyberg received her Ph.D. in mathematics in 1980 from the University of Helsinki
, with a dissertation in topology
.
Computer security
Computer security is a branch of computer technology known as information security as applied to computers and networks. The objective of computer security includes protection of information and property from theft, corruption, or natural disaster, while allowing the information and property to...
researcher, currently a professor at Helsinki University of Technology
Helsinki University of Technology
Aalto University School of Science and Technology , was the temporary name for Helsinki University of Technology during the process of forming the Aalto University...
. Her notable work includes the theory of perfect nonlinear S-boxes
Substitution box
In cryptography, an S-Box is a basic component of symmetric key algorithms which performs substitution. In block ciphers, they are typically used to obscure the relationship between the key and the ciphertext — Shannon's property of confusion...
(now known as Nyberg S-boxes), provably secure
Provable security
In cryptography, a system has provable security if its security requirements can be stated formally in an adversarial model, as opposed to heuristically, with clear assumptions that the adversary has access to the system as well as enough computational resources...
block cipher
Block cipher
In cryptography, a block cipher is a symmetric key cipher operating on fixed-length groups of bits, called blocks, with an unvarying transformation. A block cipher encryption algorithm might take a 128-bit block of plaintext as input, and output a corresponding 128-bit block of ciphertext...
design (resulting in KN-Cipher), and the cryptanalysis
Cryptanalysis
Cryptanalysis is the study of methods for obtaining the meaning of encrypted information, without access to the secret information that is normally required to do so. Typically, this involves knowing how the system works and finding a secret key...
of the stream cipher
Stream cipher
In cryptography, a stream cipher is a symmetric key cipher where plaintext digits are combined with a pseudorandom cipher digit stream . In a stream cipher the plaintext digits are encrypted one at a time, and the transformation of successive digits varies during the encryption...
s E0
E0 (cipher)
E0 is a stream cipher used in the Bluetooth protocol. It generates a sequence of pseudorandom numbers and combines it with the data using the XOR operator. The key length may vary, but is generally 128 bits.-Description:...
and SNOW
SNOW
SNOW 1.0, SNOW 2.0, and SNOW 3G are word-based synchronous stream ciphers developed by Thomas Johansson and Patrik Ekdahl at Lund University.-History:...
.
Nyberg received her Ph.D. in mathematics in 1980 from the University of Helsinki
University of Helsinki
The University of Helsinki is a university located in Helsinki, Finland since 1829, but was founded in the city of Turku in 1640 as The Royal Academy of Turku, at that time part of the Swedish Empire. It is the oldest and largest university in Finland with the widest range of disciplines available...
, with a dissertation in topology
Topology
Topology is a major area of mathematics concerned with properties that are preserved under continuous deformations of objects, such as deformations that involve stretching, but no tearing or gluing...
.