A constraint is defined as a logical relation among several unknown quantities or variables, each taking a value in a given domain. Constraint Programming (CP) is an emergent field in operations research. Constraint programming is based on feasibility which means finding a feasible solution rather than optimization which means finding an optimal solution and focuses on the constraints and variables domain rather than the objective functions. While defining a set of constraints, this may seem a simple way to model a real-world problem but finding a good model that works well with a chosen solver is not that easy. A model could be very hard to solve if it is poorly chosen.

/pdf/a-review-of-constraint-programming-4yu73a2h8q.pdf

A Review of Constraint Programming

Identifying legitimate user in DDoS attack using Petri net

Today most of the activities like trade, e-commerce are dependent on the availability of Internet. The growing use of internet services in the past few years have facilitated increase in distributed denial of service attack. Due to DDos attacks, caused by malicious hosts secured data communication over the internet is very difficult to achieve and is the need of the hour. DDos attacks are one of the most widely spread problems faced by most of the internet service providers (ISP’s). The work which had already been done was in the direction of detection, prevention and trace-back of DDos attack. Mitigation of these attacks has also gained an utmost importance in the present scenario. A number of techniques have been proposed by various researchers but those techniques produce high collateral Damage so more efforts are needed to be done in the area of mitigation of DDos attacks. This paper focuses on Distributed Denial of Service attack, surveys, classification and also proposed mitigation techniques revealed in literature by various researchers.

/pdf/router-based-mechanism-for-mitigation-of-ddos-attack-a-4anmjm3myo.pdf

ROUTER BASED MECHANISM FOR MITIGATION OF DDoS ATTACK- A SURVEY

DDoS mitigation schemes are increasingly becoming relevant in the Internet. The main hurdle faced by such schemes is the “nearly indistinguishable” line between malicious traffic and genuine traffic. It is best tackled with a paradigm shift in connection handling by attesting the path. We therefore propose the scheme called “Path Attestation Scheme” coupled with a metric called “Confidence Index” to tackle the problem of distinguishing malicious and genuine traffic in a progressive manner, with varying levels of certainty. We support our work through an experimental study to establish the stability of Internet topology by using 134 different global Internet paths over a period of 16 days. Our Path Attestation Scheme was able to successfully distinguish between malicious and genuine traffic, 85% of the time. The scheme presupposes support from a fraction of routers in the path.

/pdf/path-attestation-scheme-to-avert-ddos-flood-attacks-356n037wlb.pdf

Raktim Bhattacharjee

Papers

Path attestation scheme to avert DDoS flood attacks