Privacy-preserving Crime Reporting and Rewarding in the Presence of Active Insider and Outsider Adversaries

Abstract

Security agencies collect evidence from whistleblowers to take action against criminals. Moreover, security agencies provide rewards to encourage whistleblowers for their services. However, sometimes, security agencies may have individuals who are not trustworthy. Such insider adversaries disclose the identities of whistleblowers and modify the order of evidence submission to provide rewards to specific whistleblowers. In this paper, we present the crime-reporting and rewarding mechanism to protect the identities of whistleblowers and reward genuine and first whistleblowers. The proposed mechanism not only protects in the presence of outsider adversaries but also in the presence of active insider adversaries. To the best of our knowledge, the proposed mechanism is reliable in identifying and rewarding genuine and first whistleblowers. We use the public ledger to timestamp and record submissions and smart contracts to automatically transfer rewards to genuine and first whistleblowers. To show the feasibility, we implemented the proposed mechanism. Security and performance analysis show that the proposed mechanism is secure against active insider and outsider adversaries, reliable, and transparent.