Information Filtering and Automatic Keyword Identification by Artificial Neural Networks

Information filtering (IF) systems usually filter data items by correlating a vector of terms (keywords) that represent the user profile with similar vectors of terms that represent the data items (e.g. documents). The terms that represent the data items can be determined by (human) experts (e.g. authors of documents) or by automatic indexing methods. In this study we employ an artificial neural-network (ANN) as an alternative method for both filtering and term selection, and compare its effectiveness to “traditional” methods. In an earlier study we developed and examined the performance of an IF system that employed content-based and stereotypic rule-based filtering methods, in the domain of e-mail messages. In this study we train a large-scale ANN-based filter which uses meaningful terms in the same database of email messages as input, and use it to predict the relevancy of those messages. Results of the study reveal that the ANN prediction of relevancy is very good, compared to the prediction of the IF system: correlation between the ANN prediction and the users’ evaluation of message relevancy ranges between 0.76- 0.99, compared to correlation in the range of 0.41-0.77 for the IF system. Moreover, we found very low correlation between the terms in the user profile (which were selected by the users) and the positive causal-index terms of the ANN (which indicate the important terms that appear in the messages). This indicates that the users under-estimate the importance of some terms, failing to include them in their profiles. This may explain the rather low prediction accuracy of the IF system that is based on user-generated profiles

Minimizing the Time of Spam Mail Detection by Relocating Filtering System to the Sender Mail Server

Unsolicited Bulk Emails (also known as Spam) are undesirable emails sent to massive number of users. Spam emails consume the network resources and cause lots of security uncertainties. As we studied, the location where the spam filter operates in is an important parameter to preserve network resources. Although there are many different methods to block spam emails, most of program developers only intend to block spam emails from being delivered to their clients. In this paper, we will introduce a new and efficient approach to prevent spam emails from being transferred. The result shows that if we focus on developing a filtering method for spams emails in the sender mail server rather than the receiver mail server, we can detect the spam emails in the shortest time consequently to avoid wasting network resources.Comment: 10 pages, 7 figure

A Proposal for Dynamic Access Lists for TCP/IP Packet Filering

The use of IP filtering to improve system security is well established, and although limited in what it can achieve has proved to be efficient and effective. In the design of a security policy there is always a trade-off between usability and security. Restricting access means that legitimate use of the network is prevented; allowing access means illegitimate use may be allowed. Static access list make finding a balance particularly stark -- we pay the price of decreased security 100% of the time even if the benefit of increased usability is only gained 1% of the time. Dynamic access lists would allow the rules to change for short periods of time, and to allow local changes by non-experts. The network administrator can set basic security guide-lines which allow certain basic services only. All other services are restricted, but users are able to request temporary exceptions in order to allow additional access to the network. These exceptions are granted depending on the privileges of the user. This paper covers the following topics: (1) basic introduction to TCP/IP filtering; (2) semantics for dynamic access lists and; (3) a proposed protocol for allowing dynamic access; and (4) a method for representing access lists so that dynamic update and look-up can be done efficiently performed.Comment: 12 pages. Shortened version appeared in SAICSIT 200

Interactive Simplifier Tracing and Debugging in Isabelle

The Isabelle proof assistant comes equipped with a very powerful tactic for term simplification. While tremendously useful, the results of simplifying a term do not always match the user's expectation: sometimes, the resulting term is not in the form the user expected, or the simplifier fails to apply a rule. We describe a new, interactive tracing facility which offers insight into the hierarchical structure of the simplification with user-defined filtering, memoization and search. The new simplifier trace is integrated into the Isabelle/jEdit Prover IDE.Comment: Conferences on Intelligent Computer Mathematics, 201

Spam on the Internet: can it be eradicated or is it here to stay?

A discussion of the rise in unsolicited bulk e-mail, its effect on tertiary education, and some of the methods being used or developed to combat it. Includes an examination of block listing, protocol change, economic and computational solutions, e-mail aliasing, sender warranted e-mail, collaborative filtering, rule-based and statistical solutions, and legislation

"May I borrow Your Filter?" Exchanging Filters to Combat Spam in a Community

Leveraging social networks in computer systems can be effective in dealing with a number of trust and security issues. Spam is one such issue where the "wisdom of crowds" can be harnessed by mining the collective knowledge of ordinary individuals. In this paper, we present a mechanism through which members of a virtual community can exchange information to combat spam. Previous attempts at collaborative spam filtering have concentrated on digest-based indexing techniques to share digests or fingerprints of emails that are known to be spam. We take a different approach and allow users to share their spam filters instead, thus dramatically reducing the amount of traffic generated in the network. The resultant diversity in the filters and cooperation in a community allows it to respond to spam in an autonomic fashion. As a test case for exchanging filters we use the popular SpamAssassin spam filtering software and show that exchanging spam filters provides an alternative method to improve spam filtering performance