Vijay Kothari

Measuring the security impacts of password policies using cognitive behavioral agent-based modeling

Agent-based modeling can serve as a valuable asset to security personnel who wish to better understand the security landscape within their organization, especially as it relates to user behavior and circumvention. In this paper, we argue in favor of cognitive behavioral agent-based modeling for usable security, report on our work on developing an agent-based model for a password management scenario, perform a sensitivity analysis, which provides us with valuable insights into improving security (e.g., an organization that wishes to suppress one form of circumvention may want to endorse another), and provide directions for future work.

Combinatorial algorithms for minimizing the weighted sum of completion times on a single machine

Abstract We study the problem of minimizing the weighted sum of completion times of jobs with release dates on a single machine with the aim of shedding new light on “the simplest (linear program) relaxation” (Queyranne and Schulz, 1994 [17] ). Specifically, we analyze a 3-competitive online algorithm (Megow and Schulz, 2004 [16] ), using dual fitting. In the offline setting, we develop a primal–dual algorithm with approximation guarantee 1 + 2 . The latter implies that the cost of the optimal schedule is within a factor of 1 + 2 of the cost of the optimal LP solution.