Biblio

Hybridisation of algorithms in evolutionary computation (EC) has been used by researchers to overcome drawbacks of population-based algorithms. The introduced algorithm called mutated Artificial Bee Colony algorithm, is a novel variant of standard Artificial Bee Colony algorithm (ABC) which successfully moves out of local optima. First, new parameters are found and tuned in ABC algorithm. Second, the mutation operator is employed which is responsible for bringing diversity into solution. Third, to avoid tuning 'limit' parameter and prevent abandoning good solutions, it is replaced by average fitness comparison of worst employed bee. Thus, proposed algorithm gives the global solution thus improving the exploration capability of ABC. The proposed algorithm is tested on four classes of problems. The results are compared with six other population-based algorithms, namely Genetic Algorithm (GA), Particle Swarm Optimsation (PSO), Differential Evolution (DE), standard Artificial Bee Colony algorithm (ABC) and its two variants- quick Artificial Bee Colony algorithm (qABC) and adaptive Artificial Bee Colony algorithm (aABC). Overall results show that mutated ABC is at par with aABC and better than above-mentioned algorithms. The novel algorithm is best suited to 3 of the 4 classes of functions under consideration. Functions belonging to UN class have shown near optimal solution.

Web application attacks are an extreme threat to the world's information technology infrastructure. A web application is generally defined as a client-server software application where the client uses a user interface within a web browser. Most users are familiar with web application attacks. For instance, a user may have received a link in an email that led the user to a malicious website. The most widely accepted solution to this threat is to deploy an Intrusion Detection System (IDS). Such a system currently relies on signatures of the predefined set of events matching with attacks. Issues still arise as all possible attack signatures may not be defined before deploying an IDS. Attack events may not fit with the pre-defined signatures. Thus, there is a need to detect new types of attacks with a mutated signature based detection approach. Most traditional literature works describe signature based IDSs for application layer attacks, but several works mention that not all attacks can be detected. It is well known that many security threats can be related to software or application development and design or implementation flaws. Given that fact, this work expands a new method for signature based web application layer attack detection. We apply a genetic algorithm to analyze web server and database logs and the log entries. The work contributes to the development of a mutated signature detection framework. The initial results show that the suggested approach can detect specific application layer attacks such as Cross-Site Scripting, SQL Injection and Remote File Inclusion attacks.