Rational Oblivious Transfer

On the limits of cache-oblivious rational permutations

Permuting a vector is a fundamental primitive which arises in many applications. In particular, rational permutations, which are defined by permutations of the bits of the binary representations of the vector indices, are widely used. Matrix transposition and bit-reversal are notable examples of rational permutations. In this paper we contribute a number of results regarding the execution of th...

Cryptography in an Unbounded Computational Model

We investigate the possibility of cryptographic primitives over nonclassical computational models. We replace the traditional finite field F ∗ n with the infinite field Q of rational numbers, and we give all parties unbounded computational power. We also give parties the ability to sample random real numbers. We determine that secure signature schemes and secure encryption schemes do not exist....

Anonymous Oblivious Transfer

In this short note we want to introduce anonymous oblivious transfer a new cryptographic primitive which can be proven to be strictly more powerful than oblivious transfer. We show that all functions can be robustly realized by multi party protocols with anonymous oblivious transfer. No assumption about possible collusions of cheaters or disruptors have to be made. Furthermore we shortly discus...

A new efficient k-out-of-n Oblivious Transfer protocol

This paper presents a new efficient protocol for k-out-of-n oblivious transfer which is a generalization of Parakh's 1-out-of-2 oblivious transfer protocol based on Diffie-Hellman key exchange. In the proposed protocol, the parties involved generate Diffie-Hellman keys obliviously and then use them for oblivious transfer of secrets.

Reducing String Oblivious Transfer to Universal Oblivious Transfer