In the era of data-driven economies, incentive systems and loyalty programs have become widespread across various sectors such as advertising, retail, travel, and financial services. These systems offer benefits for both users and companies, but they also require the transfer and analysis of large amounts of sensitive data. As a result, privacy concerns have become increasingly important, leading to the need for privacy-preserving incentive protocols.
Despite the growing demand for secure and decentralized systems, there is currently a lack of comprehensive solutions. That’s why the Boomerang protocol comes as a promising innovation in this field. This novel decentralised privacy-preserving incentive protocol utilizes cryptographic black box accumulators to securely store user interactions within the incentive system. By leveraging these accumulators, the Boomerang protocol ensures that sensitive user data is protected while still enabling the transparent computation of rewards for users.
To achieve this transparency and verifiability, the Boomerang protocol incorporates zero-knowledge proofs based on BulletProofs. These proofs allow for the computation of rewards without revealing any sensitive user information. Additionally, to enhance public verifiability and transparency, the protocol utilizes a smart contract on a Layer 1 blockchain to verify these zero-knowledge proofs.
The combination of black box accumulators with selected elliptic curves in the zero-knowledge proofs makes the Boomerang protocol highly efficient. A proof of concept implementation of the protocol demonstrates its ability to handle up to 23.6 million users per day on a single-threaded backend server, with financial costs of approximately 2 US$. Furthermore, by utilizing the Solana blockchain, the protocol can handle up to 15.5 million users per day with approximate costs of only 0.00011 US$ per user.
The Boomerang protocol not only offers a significant advancement in privacy-preserving incentive protocols but also paves the way for a more secure and privacy-centric future. By addressing the privacy concerns surrounding incentive systems, this protocol provides a framework for companies to offer incentives while maintaining the privacy of their users. As the demand for privacy and data protection continues to grow, solutions like the Boomerang protocol will likely become essential in various industries.