Privacy Preserving Detection of Path Bias Attacks in Tor

Anonymous communication networks like Tor are vulnerable to attackers that control entry and exit nodes. Such attackers can compromise the essential anonymity and privacy properties of the network. In this paper, we consider the path bias attack– where the attacker induces a client to use compromised nodes and thus links the client to their destination. We describe an efficient scheme that detects such attacks in Tor by collecting routing telemetry data from nodes in the network. The data collection is differentially private and thus does not reveal behaviour of individual users even to nodes within the network. We show provable bounds for the sample complexity of the scheme and describe methods to make it resilient to introduction of false data by the attacker to subvert the detection process. Simulations based on real configurations of the Tor network show that the method works accurately in practice

Levonorgestrel intrauterine system: A first line medical therapy for idiopathic heavy menstrual bleeding

Heavy menstrual bleeding or menorrhagia is a common menstrual disorder. Currently, both medical and surgical treatment options are available for the management of heavy menstrual bleeding. Hysterectomy, one of the surgical treatment options is associated with risks and is a costly procedure. Medical treatment may be preferred for the management of heavy menstrual bleeding. Oral medical treatments have various limitations for their use. For instance, cost is a limiting factor for tranexamic acid. Limited data is available to support the effectiveness of oral contraceptives. Poor patient compliance and intolerable adverse events are some other limitations especially in long term use. Levonorgestrel intrauterine system (LNG-IUS) is one of the common medical modalities in the management of heavy menstrual bleeding. LNG-IUS has been compared with other medical options like tranexamic acid, mefenamic acid, combined estrogen-progestogen, or progesterone alone, cyclic oral medroxyprogesterone acetate (MPA) oral norethisterone and low-dose combined oral contraceptive. LNG-IUS is more effective than usual medical treatment and also reduces the effect of heavy menstrual bleeding on quality of life. Similarly, it has shown similar therapeutic effects compared to endometrial ablation. Based on its efficacy, convenience and cost of therapy, it can be considered as the first line medical therapy for the management of heavy menstrual bleeding

A generic domain specific language for financial contracts

Financial contracts require management, such as valuation, scheduling and generating legal documents. The current approach for managing financial contracts is inefficient, for lack of a universal language for representing contracts. Peyton Jones et al.'s proposed such a language, even though contracts are diverse and new ones are introduced often. We verify that Peyton Jones et al.'s language is expressive enough by using it to represent two new contracts: credit default swap and power reverse dual currency swap. We demonstrate its advantage by using the same program to value all contracts represented. More generally, we need only one program for each contract management task.M.S.Includes bibliographical references (p. 46)

Improving Answer Set Based Planning

Solving AI planning problems by transformation into (normal) logic programs and computing answer sets (stable models) has gained considerable interest over the last years. We investigate in this context a classical AI search technique, bidirectional search, where search is performed both from the initial facts towards the goal and vice versa. Our contribution is to show how bidirectional search can be realized in the logic programming/answer set paradigm to planning. This seems not having been investigated so far. We report on practical experiments on planning problems from an AIPS competition and show how our approach helps speeding up the planning process. We perceive our contribution mainly as a technique that is compatible with and complementary to existing extensions and improvements, rather than as a concrete planning system. Keywords