If I have a credential on KILT, can the rest of the world trust it?

There are two different things here; the attester, and the truth that the attester actually issued the credential. 

So what the blockchain takes care of is that we can make sure that if someone gets a credential from, for example, a credit rating agency – they’re the claimer – and they show this credential to you, then from the blockchain side, you can be absolutely sure that it’s this person sending you the credential. You can also be absolutely sure that this credit rating agency was the attester that issued the credential. They can never deny that they issued it. And if the agency revokes the credential, you can be absolutely sure that you will be able to see that. That’s the three things that come out of the blockchain.

But if this agency made a mistake in issuing the credential, you will never be able to see it on the blockchain. And if they just issued useless credentials, if they say that this person has a high credit score and that they’ll be able to pay back a huge mortgage but actually they have no money in the bank and no way of earning money, then it’s the agency’s fault. And then that agency’s business model as an attester is probably going to break down because you are going to tell everyone that someone had a credential from this credit rating agency to say that they have a high credit score but actually they don’t have the money to pay you back. And then this credit rating agency will probably close down after a while because it loses the trust of the verifiers, which is you in this case. 

In simple terms, KILT is creating the infrastructure where you can convey your trust of others and get credentials that include the trust of others, and then convey these credentials to others who again trust the people that you trust. It’s like rebuilding the real world on the internet, using the old idea of what a trusted entity is – someone who earns trust over time and constantly delivers good work to make sure that the trust doesn’t go away.

It’s said that the blockchain is trustless, but some trust is still needed in the world. If you take the trust out by replacing intermediaries with mathematical truth that’s another thing – replace the trust people have with the intermediary with a mathematical truth. KILT does that. KILT replaces the intermediary with the mathematical truth of the blockchain. But still you want to trust the attester, the issuer of the credential, which is a completely different thing

So the blockchain is not building reputation systems. Trust isn’t generated by the blockchain, trust is built in the real world. The attester’s reputation as a trusted entity is generally built off the blockchain. But the blockchain is building a system where the verifier can be absolutely sure which claimer sent the credential and which attester issued it. And that’s a big step forward for digital identity.