Hybrid Key Duplication Hashing Techniques for IP Address Lookup

Rujiroj Tiengtavat,Wei-Ming Lin

doi:10.4236/ijcns.2011.45037

Abstract

This In the past decade there has been an increasing need for designs to address the time and cost efficiency issues from various computer network applications such as general IP address lookup and specific network intrusion detection. Hashing techniques have been widely adopted for this purpose, among which XOR-operation-based hashing is one of most popular techniques due to its relatively small hash process delay. In most current commonly used XOR-hashing algorithms, each of the hash key bits is usually explicitly XORed only at most once in the hash process, which may limit the amount of potential randomness that can be introduced by the hashing process. In [1] a series of bit duplication techniques are proposed by systematically duplicating one row of key bits. This paper further looks into various ways in duplicating and reusing key bits to maximize randomness needed in the hashing process so as to enhance the overall performance further. Our simulation results show that, even with a slight increase in hardware requirement, a very significant reduction in the amount of hash collision can be obtained by the proposed technique.

Highlights

Fast address lookup or identification matching has become critical to the feasibility of many modern applications
In most current commonly used XOR-hashing algorithms, each of the hash key bits is usually explicitly XORed only at most once in the hash process, which may limit the amount of potential randomness that can be introduced by the hashing process
Simulation runs are performed on randomly generated data sets and real IP data sets to demonstrate the performance improvement of the minimal Induced Duplication Correlation (IDC) dupli- cation XOR hash technique over other techniques with no duplication

Summary

Introduction

One modern example is in that the routers in wide-area networks have to look through a large database, a routing table, for a forwarding link that matches the given destination address [2]. Another example that calls for imminent attention these days is in the area of internet security, in which intrusion detection demands rapid evaluation of client requests. Hashing in essence provides a process of mapping records (hash keys) between two regions, a domain space (the database) and a hash space [3]. Known as a hashing function, issues a set of directives outlining the mapping of a hash key (or record) from the domain space into hash space by creating a corresponding hash value

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