IACR News item: 27 February 2013
Paul Baecher, Christina Brzuska, Marc Fischlin
ePrint ReportHaving precise notions for such reductions is very important when it comes to black-box separations, where one shows that black-box reductions cannot exist. An impossibility result, which clearly specifies the type of reduction it rules out, enables us to identify the potential leverages to bypass the separation. We acknowledge this by extending the RTV framework in several respects using a more fine-grained approach. First, we capture a type of reduction---frequently ruled out by so-called meta-reductions---which escapes the RTV framework so far. Second, we consider notions that are ``almost black-box\'\', i.e., where the reduction receives additional information about the adversary, such as its success probability. Third, we distinguish explicitly between efficient and inefficient primitives and adversaries, allowing us to determine how relativizing reductions in the sense of Impagliazzo and Rudich (STOC, 1989) fit into the picture.
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