Blockchain-based Recommender Systems: Applications, Challenges and Future Opportunities

TL;DR

This paper reviews how blockchain technology can enhance security and privacy in recommender systems across various domains, discussing challenges, solutions, and future research directions.

Contribution

It provides a comprehensive taxonomy of security and privacy challenges and reviews existing blockchain-based frameworks for recommender systems.

Findings

Blockchain improves security and privacy in recommender systems.

Current frameworks address some challenges but lack complete solutions.

Future research opportunities include developing more resilient and scalable blockchain solutions.

Abstract

Recommender systems have been widely used in different application domains including energy-preservation, e-commerce, healthcare, social media, etc. Such applications require the analysis and mining of massive amounts of various types of user data, including demographics, preferences, social interactions, etc. in order to develop accurate and precise recommender systems. Such datasets often include sensitive information, yet most recommender systems are focusing on the models' accuracy and ignore issues related to security and the users' privacy. Despite the efforts to overcome these problems using different risk reduction techniques, none of them has been completely successful in ensuring cryptographic security and protection of the users' private information. To bridge this gap, the blockchain technology is presented as a promising strategy to promote security and privacy preservation in recommender systems, not only because of its security and privacy salient features, but also due to its resilience, adaptability, fault tolerance and trust characteristics. This paper presents a holistic review of blockchain-based recommender systems covering challenges, open issues and solutions. Accordingly, a well-designed taxonomy is introduced to describe the security and privacy challenges, overview existing frameworks and discuss their applications and benefits when using blockchain before indicating opportunities for future research.