This paper presents a lightweight framework for privacy-preserving cross-organizational process mining, enhanced by blockchain technology. Our goal is to enable secure data sharing among multiple stakeholders without exposing sensitive process details. The proposed approach integrates a smart-contract-layer for transparent access control, modular encryption of critical attributes, and minimal on-chain data storage to maintain system scalability. Initial evaluations on selected administration and insurance case studies show that the hybrid on-chain/off-chain architecture preserves data confidentiality while allowing meaningful process discovery and conformance checking. This research paves the way for trustworthy collaboration in settings where participants wish to share process insights but must safeguard proprietary information.