CONTENTS - Emerald

041516 `Intrinsic Weakness of Keystream Generators'
JD Golic, Asiacrypt 94 pp 72{83
If an arbitrary keystream generator has M bits of state, then there is a linear
function of at most M +1 bits kt; :::kt+M which isanunbalanced function of the initial
state and whose probability distribution is independent oftif the next-state function
is balanced. This can be used as the basis for linear approximation attacks, which are
discussed in the case of several generators.
041517 `Three Characterisations of Non-Binary Correlation-Immune and
Resilient Functions'
K Gopalakrishnan, DR Stinson, Designs, Codes and Cryptography v 5 no 3 (May 95)
pp 241{251
The authors generalise the Xiao-Massey lemma to the case of odd characteristic,
and use it to characterise t-th order correlation immune and resilient functions of n
variables over GF (q). There are three equivalent forms of this: in terms of a matrix of
incidence probabilities, a sum of roots of unity, and a set of orthogonal arrays.
041518 `Linear dependencies in product ciphers'
HM Gustafson, AW Pettitt, EP Dawson, LJ O'Connot, Australasian Journal of Combinatorics
v 10 (Sep 94) pp 115{129
The authors survey the various kinds of linear dependency which a block cipher
can exhibit and which make it vulnerable to di erential, linear and other attacks. They
show that these dependencies are very unlikely to occur in a random cipher.
041519 `On the Security of the CAST Encryption Algorithm'
HM Heys, SE Tavares, Proceedings of the Canadian Conference onElectrical and Computer
Engineering, September 94, Halifax
The authors further describe the CAST algorithm used in North American digital
cellular telephones, and whose principles were rst described in 022501. It is a Feistel
cipher with a round function of four 8 by 32 bit S-boxes, whose outputs are x-ored
together. Various results on resistance to linear, di erential and related-key analysis
are given.
041520 `The Design of Substitution-Permutation Networks Resistant to
Di erential and Linear Cryptanalysis'
H Heys, S. Tavares, Fairfax 94 pp 148{155
A scheme for a block cipher is proposed based on the substitution-permutation
networks which were proposed by Feistel in the early seventies. The authors derive
upper bounds on the probability of the best characteristic and of the best linear approximation.
They conclude that large S-boxes with good di usion properties increase
the resistance to di erential cryptanalysis, and that linear transformations between the
rounds can increase the resistance to linear cryptanalysis.
041521 `How to strengthen DES against two robust attacks'
K Kim, S Lee, S Park, D Lee, JW-ISC 95 pp 173{182
The authors propose an alternate set of DES S-boxes which are claimed to be more
secure against both linear and di erential cryptanalysis.
041522 `Classi cation of Hadamard matrices of order 28'
H Kimura, Discrete Mathematics v 133 (Oct 94) pp 171{180
The author classi es all Hadamard matrices of order 28. Those with trivial Kmatrices
correspond to the squares in GF (27).
041523 `A model for secret-key cryptography using chaotic synchronisation'
L Kocarev, T Stojanovski, ISITA 94 pp 251{255
A new application of the concept of chaotic synchronization to secure communication
systems is proposed. This is a chaotic system which takes the information signal
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