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A lower bound on the probability of deception in multiple authentication

New bounds are derived for the probabilities of successful attack on multiple authentication schemes by removing the frequently assumed 'freshness' constraint on the source states. We prove that the overall probability of successful deception, PD(L), for a sequences of L uses of the authentication channel, is bounded from below by max(k/v, 1/√b). We also show that if PD{L) = 1/√b, then the key ent

On a fast correlation attack on certain streaxn ciphers

In this paper we present a new algorithm for the recovery of the initial state of a linear feedback shift register when a noisy output sequence is given. Our work is focussed on the investigation of the asymptotical behaviour of the recovery process rather than on the construction of an optimal recovery procedure. Our results show the importance of low-weight checks and show also that the complexi

Windmill pn-sequence generators

A windmill generator is a high-speed sequence generator capable of producing blocks of v consecutive symbols in parallel. It consists of v feedback-shift registers linked into a ring. The sequences are identical to those produced by a linear feedback-shift register with feedback polynomial of the special ('windmill') form f(t) = α(tv) - tLβ(t-v), where α(t) and β(t) are polynomials of degree less

Windmill generators a generalization and an observation of how many there are

The windmill technique has several practical advantageous over other techniques for high-speed generation or blockwise generation of pn-sequences. In this paper we generalize previous results by showing that if f(t)=α(t v) − β(t −v)t L is the minimal polynomial of a pn-sequence, then the sequence can be generated by a windmill generator. For L = 1,..127, and ν = 4, 8, 16 such that L ≡ ±3 mod 8 no

Linear complexity profile of sequences over the field GF(Q)

Summary form only given. The author extends Reuppel's concept of the linear complexity profile of binary sequences to sequences over an arbitrary finite field and provides formulas for the expected linear complexity and its variance of sequences Sn of length n over GF(q). He shows that the variance approaches 1/q when q approaches ∞. He presents criteria that could be useful when using the linear

GENERAL CLASS OF WINDMILL POLYNOMIALS FOR FAST M-SEQUENCE GENERATION.

Summary form only given. The windmill technique is an attractive alternative to the Lempel-Eastman technique for fast m-sequence generation. The author has generalized the class of linear recurrence relations for which the windmill technique results in an m-sequence generator. A converse to a set of known necessary conditions has been obtained.

Keyed logic BIST for Trojan detection in SoC

As demonstrated by the recent attack on Intel's Ivy Bridge processor, the traditional Logic Built-In Self-Test (LBIST) methods do not provide adequate protection of SoC against malicious modifications known as hardware Trojans. In this paper, we introduce a simple but efficient countermeasure against hardware Trojans which exploits non-zero aliasing probability of LBIST. We propose to generate LBI

Incremental authentication of tree-structured documents

A new message authentication code (MAC) is described that exploits the tree structure present in many modern document formats, e.g. SGML and XML. The new code supports incremental updating of the cryptographic checksum in the process of making incremental changes to the document. Theoretical bounds on the probability of a successful substitution attack are derived. Through experimental results we

Fast message authentication using efficient polynomial evaluation

Message authentication codes (MACs) using polynomial evaluation have the advantage of requiring a very short key even for very large messages. We describe a low complexity software polynomial evaluation procedure, that for large message sizes gives a MAC that has about the same low software complexity as for bucket hashing but requires only small keys and has better security characteristics.

Fast authentication codes based on random polynomial residue classes

The verification of the authenticity of a text document or a datafile is one of the main applications of cryptographic techniques. A common used technique for this purpose is the application of a message authentication code (MAC). Usually the MAC computation has to be done in software. Based on the relationship between error-correcting codes and so-called families of almost universal hash function

Estimation of escape probabilities for PPM based on universal source coding theory

Some of the best compression ratios for text compression are provided by the PPM (prediction by partial matching) class of algorithms. These algorithms are based on arithmetic coding using a fixed-depth Markov chain model of the source, i.e., the subsequence of symbols generated in any state s of the source is assumed to be the output of a memoryless subsource w=w(s). One of the most crucial steps

A coding theoretic approach to attack certain stream ciphers

We present a coding theoretic approach to the problem the initial state recovery of a linear feedback shift register when a noisy output sequence is given. Our work is focused on the investigation of the asymptotical behaviour of the recovery process. We give two algorithms which will work for shift registers with arbitrary feedback polynomial. Furthermore, the number of required given noisy symbo

On the construction of authentication codes with secrecy and codes withstanding spoofing attacks of order L ≥ 2

We present an analysis of some known cartesian authentication codes and their modification into authentication codes with secrecy, with transmission rate R = r/n, where n = 2, 3, …, and 1 ≤ r ≤ n - 1 using (n - r)(r + 1) q-ary key digits. For this purpose we use a grouping technique. Essentially the same key grouping technique is used for the construction of codes that withstand spoofing attacks o