I came to gradually realize that it was possible to develop very sophisticated cryptographic protocols with a little bit of imagination.

I am still impressed by the implementation of protocols that are able to provide such services as zero-knowledge proof for instance ..

Recently in the news there has been discussion about following the evolution of the covid thanks to applications that track citizens. This is obviously not without major problems of privacy.

I was wondering : would there be a way to use the magic of cryptography in order to provide some solutions to help overcoming this impasse ?

For example, someone could somehow partially reveal the information about whether or not he is positive to the disease, but only people of his choice could use that information - on the other hand, people could query some sort of common or rizomatic register to find out their chances of being positive (i.e. whether they have been in contact with positive cases or not) but without knowing who is positive if they are.

Another example would be the possibility of following the geographical evolution of the disease anonymously by creating groups of individuals who are spatially close to each other, and by mixing the information they bring about their positivity.

It's a very open question, I'm just suggesting a few things to illustrate my idea a little bit. I think there are people here who have much better skills in cryptography than I do, and they will certainly be better able to define a more rigorous framework to formalize the issue.

Feel free to share your thoughts