Delayed choice relativistic quantum bit commitment with arbitrarily long commitment time

TL;DR

This paper introduces a relativistic two-round bit commitment scheme enabling indefinite commitment time and simultaneous commitment and reveal, with potential applications in secure multiparty computations and classical bit string commitments.

Contribution

It presents a novel relativistic multiparty bit commitment scheme with indefinite commitment time and practical implementation using minimal entanglement requirements.

Findings

Scheme allows arbitrarily long commitment duration.

It can be generalized to multiparty scenarios.

Applicable with existing technology, requiring minimal entanglement.

Abstract

We propose here a two-round relativistic bit commitment scheme where committer commits in the first round and then confirms his/her commitment in the second round. The scheme offers indefinite commitment time where both committer and receiver extract non-locally correlated measurement outcomes during the scheme that can be stored and revealed after arbitrarily long time. We show that the proposed scheme turns out to be a multiparty bit commitment scheme where both parties commit and reveal simultaneously. The multiparty generalization would have applications in business and secure multiparty computations such as managing joint bank account, holding joint shares in stock exchange and blind bidding. The same bit commitment scheme can also be used for the commitment of arbitrarily long classical bit strings. The scheme can be applied efficiently with existing technologies; entanglement is required only for time t=x/c where x is the special distance, can be as small as possible, between the committer and receiver.