  Consumers frequently interact with reputation systems to rate products,
services, and deliveries. While past research extensively studied different
conceptual approaches to realize such systems securely and
privacy-preservingly, these concepts are not yet in use in business-to-business
environments. In this paper, (1) we thus outline which specific challenges
privacy-cautious stakeholders in volatile supply chain networks introduce, (2)
give an overview of the diverse landscape of privacy-preserving reputation
systems and their properties, and (3) based on well-established concepts from
supply chain information systems and cryptography, we further propose an
initial concept that accounts for the aforementioned challenges by utilizing
fully homomorphic encryption. For future work, we identify the need of
evaluating whether novel systems address the supply chain-specific privacy and
confidentiality needs.
