Comment by Canada
3 years ago
Can this be applied usefully to non-public datasets?
Would it be feasible to add some other zero knowledge proof to this that would confirm a user has paid a subscription for access? For example, if this were a news site, the user would have to prove a valid subscription to read articles, but the site would not be able to know which articles any subscriber decided to read?
If that is possible, what could the site to to prevent a paying subscriber from sharing their access to an unreasonable number of others? Would it be possible to impose a rate limit per subscriber?
The simplest approach would be to just charge people per-query (or charge in levels, depending on the number of queries). This could be done in the standard way (you have to log in, pay the site, and then it gives you an API key or just session token, and logs how many queries you make). I think you can avoid having to use a ZKP this way, since that will make things much more complicated and possibly costly.
I'm no cryptographer, but it seems to me you could implement this using the same algorithm as cloudfare for tor, which generates anonymous tokens from an adhoc webpage