Cryptographic protocols often make use of nested cryptographic primitives, for example signed message digests, or encrypted signed messages. Gordon and Jeffrey’s prior work on types for authenticity did not allow for such nested cryptography. In this work, we present the pattern-matching spi-calculus, which is an obvious extension of the spi-calculus to include pattern-matching as primitive. Th...

The power of weighted nite automata to describe very complex images was widely studied, see [5, 6, 7]. Finite automata can be also used as an e ective tool for compression of twodimensional images. There are some software packages using this type of compression, see [12, 6]. We consider the complexity of some pattern-matching problems for two-dimensional images which are highly compressed using...

This paper presents a new cost-efficient realization scheme of pattern matching circuits in FPGA structures with embedded memory blocks (EMB). The general idea behind the proposed method is to implement combinational circuits using a net of finite state machines (FSM) instead. The application of functional decomposition method reduces the utilization of resources by implementing FSMs using both...

In this paper we consider the problem of secure pattern matching that allows singlecharacter wildcards and substring matching in the malicious (stand-alone) setting. Our protocol, called 5PM, is executed between two parties: Server, holding a text of length n, and Client, holding a pattern of length m to be matched against the text, where our notion of matching is more general and includes non-...

We study a class of finite state machines, called w-matching machines, which yield to simulate the behavior of pattern matching algorithms while searching for a pattern w. They can be used to compute the asymptotic speed, i.e. the limit of the expected ratio of the number of text accesses to the length of the text, of algorithms while parsing an iid text to find the pattern w. Defining the orde...

Given a permutation T of 1 to n, and a permutation P of 1 to k, for k ≤ n, we wish to find a k-element subsequence of T whose elements are ordered according to the permutation P . For example, if P is (1, 2, . . . , k), then we wish to find an increasing subsequence of length k in T ; this special case can be done in time O(n log log n) [CW]. We prove that the general problem is NP-complete. We...

Given permutations T and P of length n and m, respectively, the Permutation Pattern Matching problem asks to find allm-length subsequences of T that are order-isomorphic to P . This problem has a wide range of applications but is known to be NP-hard. In this paper, we study the special case, where the goal is to only find the boxed subsequences of T that are order-isomorphic to P . This problem...

It is quite appealing to base the description of pattern-based searches on positive as well as negative conditions. We would like for example to specify that we search for white cars that are not station wagons. To this end, we define the notion of anti-patterns and their semantics along with some of their properties. We then extend the classical notion of matching between patterns and ground t...

A palindrome is a string that reads the same forward and backward. For a string x, let Pals(x) be the set of all maximal palindromes of x, where each maximal palindrome in Pals(x) is encoded by a pair (c, r) of its center c and its radius r. Given a text t of length n and a pattern p of length m, the palindrome pattern matching problem is to compute all positions i of t such that Pals(p) = Pals...

We introduce variant types and a pattern matching operation to synchronous dataflow languages. These languages are used in the design of reactive systems. As these systems grow increasingly complex, the need for abstraction mechanisms, in particular, data and control structures, is critical. Variant types provide a mechanism to precisely model structured data. The pattern matching operation, de...