Web of Trust-based decentralized ID system

[yanmaani]

Is your feature request related to a problem? Please describe.
ZeroNet has some problems with spam. It also has problems of the ID systems going down. There are partial solutions to this, such as block-lists, but they suffer from 2 main issues:

• They're opt-out. You have to see the spam to block it. Since creating accounts is costless, this is compounded.
• They're not shared. This means that every person has to see the spam to block it.

Describe the solution you'd like
My proposal is to add a web-of-trust based system. This has the following traits:

• Registration is done by contacting anyone who's already a member of the network - in practice, there exist automated services where all you have to do is to fill in a CAPTCHA
• Spam filtering is done by deciding which users you trust - each user can adapt to their own definition of spam
• There is no need for a central authority.
• Spam is "automatically" hidden, as the trust you start out with is very low and so it takes very little - in the beginning - to knock you out of it.

Web of Trust is already implemented in FMS, and there are quite some detailed technological specifications on how it works that I can dig up if anyone's interested.

Describe alternatives you've considered
It'd be possible to use proof of work, but it's not great since the punishment for legitimate users and spammers is the same, and nothing prevents spammers from just burning CPU cycles.

Blockchains will not help you here, and you should not suggest them.

Additional context
It might be worthwhile to bootstrap the Web of Trust from the existing set of CA-authorized users. Web of Trust also has the advantage of having portable identities.

[yanmaani]

Dupe #156.