Also highly recommend this paper by Fennie Wang and Primavera De Filippi:
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3524367
( Self-Sovereign Identity in a Globalized World: Credentials-Based Identity Systems as a Driver for Economic Inclusion )
Self-sovereign identity has some great use cases, even if it does not solve Sybil attack problems. Further, being able to establish identity at all is still a major problem in many places in the world and a barrier to financial inclusion.
This essay introduces Self-Sovereign Identity very nicely! Even deeper deep dive into this topic :
Sybil attacks are not solved with the "Soul" bound reputation approach. This was mathematically proven some years ago by Harvard University phd student Sven[0]. See his impossibility results on "weakly beneficial Sybil attacks" and "single report responsiveness property". The blockchain crowd has not yet discovered this, fake identities are an unsolved problem.
Startups be aware. European Commission now has an official "26 000 000.00 EUR" "estimated value" open offer for SSI wallet solutions [1]. Prior for basic service called "EBSI" was 35 million, won by IBM Hyperledger. That now works, Dev API [2]. Upcoming Europe directive states that by 2024 all citizens can apply for a digital identity, if they want one.
(self-promotion..) State-of-the-art: Delft University trustless SSI solution with running code and field-tested zero-knowledge proofs. Scientific publication "A Truly Self-Sovereign Identity System", published at IEEE LCN conference[3]. Disclaimer: we got the government contract for doing privacy-first digital identity. We integrated our own Tor-fork based on UDP for solid privacy with verifiable credential stack, see Github deep link [4].
In the case of bitcoin, isn't Sybil prevented by requiring a majority hash rate? I think I don't understand what attack you're considering in this context.
There is a certain company that may or may not be bought by $43 billion, depending on its ability to determine how many of its users are actual humans.
But they could easily change that by requiring everyone to submit their government ID. Look at Facebook's Real Name Policy [0], which was already not well received. Determining if the users are actual humans is easy, doing it without any loss of privacy is hard, because at in some part of the trust chain, a person has to provide proof to some trusted organization they are human.
Sure. But isn't what you are describing exactly the point of the sovereign/decentralized identity trilemma?
Anyway, the point is not even that Twitter needs to be able to identify its users. Twitter just needs to get rid of its bot problem. To solve that problem, they could simply charge their users $5 and promise to refund if after some vetting period (by their fraud detection and other users). The downside of this approach, of course, is that it would deter not just bots but also a large number of legitimate users who wouldn't be interested in paying to sign-up.
Yes, quite sure as I worked several years on this problem and I am speaking from my direct experience of working with and speaking to financial and micro-finance institutions in 80+ countries (see my profile). A majority of the institutions I spoke with had establishing identity as their #1 problem.
Methods existing in one place (e.g. the United States) does not mean that those methods are established and/or will work in another place (e.g. Sierra Leone). This is a multi-faceted problem that involves government, infrastructure, and technology.
Further, there are improvements to be made even in the U.S. For instance, I cannot digitally establish my identity with several providers. Why? Because I do not and have never used credit and those providers rely on the "3 questions" KYC check via a credit bureau.
For those who want to go deeper, highly recommend reading up more on
DIDs https://w3c.github.io/did-use-cases/ Verifiable Credentials: https://www.w3.org/TR/vc-data-model/
Some people working in the space to follow: https://twitter.com/kimdhamilton https://twitter.com/IdentityWoman https://twitter.com/ChristopherA
Also highly recommend this paper by Fennie Wang and Primavera De Filippi: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3524367 ( Self-Sovereign Identity in a Globalized World: Credentials-Based Identity Systems as a Driver for Economic Inclusion )
Self-sovereign identity has some great use cases, even if it does not solve Sybil attack problems. Further, being able to establish identity at all is still a major problem in many places in the world and a barrier to financial inclusion.