We propose a convertible undeniable signature scheme without random oracles. Our construction is based on Waters’ and Kurosawa and Heng’s schemes that were proposed in Eurocrypt 2005. The security of our scheme is based on the CDH and the decision linear assumption. Comparing only the part of undeniable signatures, our scheme uses more standard assumptions than the existing undeniable signature...

A firm receives orders that will be required at an uncertain time given by an Erlang distribution, and over time observes the associated independent exponential events. The firm, in turn, places orders at a linear cost from a supplier with fixed lead time l and has the option of converting (expediting) each order, at a cost, over a certain time interval after the order is originally placed. A c...

The Federal Court of Appeal recently rendered its judgment in Citibank15 and affirmed the Tax Court of Canada’s earlier decision.16 The issue in Citibank was whether certain shares constituted “term preferred shares,” as defined in subsection 248(1) of the Act. Where a specified financial institution (SFI) acquires term preferred shares in the ordinary course of business, subsection 112(2.1) of...