Motivated by strong Karp-Lipton collapse results in bounded arithmetic, Cook and Kraj́ıček [1] have recently introduced the notion of propositional proof systems with advice. In this paper we investigate the following question: Given a language L, do there exist polynomially bounded proof systems with advice for L? Depending on the complexity of the underlying language L and the amount and type ...

In this paper, we present an O(n log3 n) time algorithm for finding shortest paths in a planar graph with real weights. This can be compared to the best previous strongly polynomial time algorithm developed by Lipton, Rose, and Tarjan in 1978 which ran in O(n3=2) time, and the best polynomial algorithm developed by Henzinger, Klein, Subramanian, and Rao in 1994 which ran in e O(n4=3) time. We a...

In this paper we analyze practical aspects of the differential fault attack on RSA published by Boneh, Demillo and Lipton from Bellcore. We focus on the CRT variant, which requires only one faulty signature to be entirely broken provided that no DFA countermeasures are in use. Usually the easiest approach for the attacker is to introduce a fault in one of the two RSA-CRT exponentiations. These ...

Using a complete panel of Ghanaian cocoa producers’ societies in the 1930s, we investigate whether group interaction problems threatened i) capital accumulation, ii) cocoa sales and iii) cooperative survival as membership size increased. We find evidence of group interaction problems. The net effect, however, is positive indicating gains from economies of scale as cooperatives expanded their me...

Three recent studies (Pearson, 2012; Pearson, Ross, & Webster, 2012) purported to test the revised dual representation theory of posttraumatic stress disorder (Brewin, Gregory, Lipton, & Burgess, 2010) by manipulating the amount of additional information accompanying traumatic stimulus materials and assessing the effect on subsequent intrusive memories. Here we point out that these studies invo...