Permissions within a blockchain

Question

Everything I've been reading about blockchain from my understanding says that even on a private blockchain, every participant can view all transactions. I've seen it mentioned that a use case for block chain could be the sharing of medical data. So for example if I had a blockchain that holds the medical history of every person from birth to death in a country. Is there no way of setting up permissions so that only data relating to a person and those who have been given permission to that person's data can view it? If the data is stored on every node in a blockchain, how is a person's computer supposed to have the capacity to store the medical data of every person in a country?

Answer 1

To answer your question, try looking up Medrec when it comes to health care. Most of the research is done towards dealing with keeping the data off the chain. In addition, there are other blockchains that might provide a better solution, for more privacy. Such as, try looking up the quorum by JP Morgan. There is various type of formats that are being looked at but these can give you two possible solutions. Also, check out Health Nexus' whitepaper, which deals with medical blockchain technology. Let me know if you need more links. Have shared one below for your help!!

https://github.com/jpmorganchase/quorum