Adaptive Concurrent Non-Malleability with Bare Public-Keys

TL;DR

This paper develops a framework for concurrent non-malleability in the bare public-key model, demonstrating that secure, round-efficient cryptography with adaptive input selection is achievable without trusted assumptions.

Contribution

It formulates CNM in the BPK model and constructs round-efficient protocols with full adaptive input selection, clarifying subtleties in this setting.

Findings

CNM can be achieved in the BPK model without trusted assumptions

Protocols with full adaptive input selection are round-efficient

The work clarifies subtleties of adaptive CNM in the BPK model

Abstract

Concurrent non-malleability (CNM) is central for cryptographic protocols running concurrently in environments such as the Internet. In this work, we formulate CNM in the bare public-key (BPK) model, and show that round-efficient concurrent non-malleable cryptography with full adaptive input selection can be established, in general, with bare public-keys (where, in particular, no trusted assumption is made). Along the way, we clarify the various subtleties of adaptive concurrent non-malleability in the bare public-key model.