Extending Oblivious Transfers EÆ

Extending Oblivious Transfers Efficiently

We consider the problem of extending oblivious transfers: Given a small number of oblivious transfers “for free,” can one implement a large number of oblivious transfers? Beaver has shown how to extend oblivious transfers given a one-way function. However, this protocol is inefficient in practice, in part due to its non-black-box use of the underlying one-way function. We give efficient protoco...

Extending Oblivious Transfers Efficiently - How to get Robustness Almost for Free

At Crypto 2003 Ishai et al. gave a protocol which given a small number of (possibly extremely inefficient) oblivious transfers implements an essentially unbounded number of oblivious transfers for an additional overhead, per oblivious transfer, of computing and sending only two hash values. This highly efficient protocol is however only passive secure. To get active security, except with probab...

Cache-Oblivious Planar Shortest Paths

We present an efficient cache-oblivious implementation of the shortest-path algorithm for planar graphs by Klein et al., and prove that it incurs no more than O ` N B1/2− + N B logN ́ block transfers on a graph with N vertices. This is the first cache-oblivious algorithm for this problem that incurs o(N) block transfers.

Equivalence Between Two Flavours of Oblivious Transfers

Cache-Oblivious Iterated Predecessor Queries via Range Coalescing

In this paper we develop an optimal cache-oblivious data structure that solves the iterated predecessor problem. Given k static sorted length-n lists L1, L2, . . . , Lk and a query value q, the iterated predecessor problem is to find the largest element in each list which is less than q. Our solution to this problem, called “range coalescing”, requires O(logB+1 n + k/B) memory transfers for a q...