Quantum preprocessing for information-theoretic security in two-party computation
This work addresses security in two-party computation for cryptography and quantum computing, but it appears incremental as it builds on existing concepts like one-time tables and no-signaling correlations.
The authors tackled the problem of achieving information-theoretic security in two-party computation without a trusted third party by proposing quantum protocols to generate one-time tables, showing that the probability of generating useful tables can approach 1 in noiseless cases under weak assumptions.
In classical two-party computation, a trusted initializer who prepares certain initial correlations, known as one-time tables, can help make the inputs of both parties information-theoretically secure. We propose some bipartite quantum protocols with possible aborts for approximately generating such bipartite classical correlations with varying degrees of privacy, without introducing a third party. Under some weak requirements for the parties, the security level is nontrivial for use in bipartite computation. We show that the security is sometimes dependent on the noise level, but we propose a method for dealing with noise. The security is "forced security", which implies that the probability that some useful one-time tables are generated can approach $1$ in the noiseless case under quite weak assumptions about the parties, although the protocols allow aborts. We show how to use the generated one-time tables to achieve nontrivial information-theoretic security in generic two-party classical or quantum computation tasks, including (interactive) quantum homomorphic encryption. Our methods provide check-based implementations of some no-signaling correlations, including the PR-box type, with the help of communication which carry no information about the inputs in the generated correlations.