  Electronic health record (EHR) management systems require the adoption of
effective technologies when health information is being exchanged. Current
management approaches often face risks that may expose medical record storage
solutions to common security attack vectors. However, healthcare-oriented
blockchain solutions can provide a decentralized, anonymous and secure EHR
handling approach. This paper presents PREHEALTH, a privacy-preserving EHR
management solution that uses distributed ledger technology and an Identity
Mixer (Idemix). The paper describes a proof-of-concept implementation that uses
the Hyperledger Fabric's permissioned blockchain framework. The proposed
solution is able to store patient records effectively whilst providing
anonymity and unlinkability. Experimental performance evaluation results
demonstrate the scheme's efficiency and feasibility for real-world scale
deployment.
