Technology parameter maps summarize experiences with specific parameters in production processes, e.g., milling, and significantly help in designing new or improving existing production processes. Businesses could greatly benefit from globally exchanging such existing knowledge across organizations to optimize their processes. Unfortunately, confidentiality concerns and the lack of appropriate designs in existing data space frameworks—both in academia and industry—greatly impair respective actions in practice. To address this research gap, we propose MapXchange, our homomorphic encryption-based approach to combine technology parameters from different organizations into technology parameter maps while accounting for the confidentiality needs of involved businesses. Central to our design is that it allows for local modifications (updates) of these maps directly at the exchange platform. Moreover, data consumers can query them, without involving data providers, to eventually improve their setups. By evaluating a real-world use case in the domain of milling, we further underline MapXchange’s performance, security, and utility for businesses.