In Web 3.0 the user owns the information. Decentralized Identity Documents (DID documents) allow users to create their own digital identity and decentralized cryptographic material resistant to quantum computing. A patient’s DID document also contains a unique identifier for cross-border healthcare, endpoints for receiving DIDComm messages and for SOS services, and additional identifiers (passport, etc.). We propose a blockchain for cross-border healthcare to store the evidence of different electronic, physical identities, and identifiers, but also the rules approved by the patient or legal guardians to access patient data. The International Patient Summary (IPS) is the de facto standard for cross-border healthcare and includes an index of information classified into sections (HL7 FHIR Composition) that healthcare professionals and services can update and read on the patient’s SOS service, then retrieving all the necessary patient information from the different FHIR API endpoints of different healthcare providers according to the approved rules.