Knudsen has published a couple of papers on cryptanalysis of cryptographic primitives, including the R-MAC scheme, the
SHA-1 and
MD2 hash functions, and a couple of block
ciphers:
DES,
DFC,
IDEA,
ICE,
LOKI,
MISTY,
RC2,
RC5,
RC6,
SC2000,
Skipjack,
Square and
SAFER. Knudsen was involved in designing some ciphers:
AES candidates
DEAL,
Serpent (the latter in conjunction with
Ross Anderson and
Eli Biham) and the lightweight cipher
PRESENT included in ISO/IEC 29192-2:2019. He was involved in designing
Grøstl, 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 and
integral cryptanalysis. ==Industry and Research Contributions==