[mangodwango]

This is interesting, but I’m really skeptical about the implementation. I’d really kind to see a much more concrete specification, and details about adversarial conditions.

It feels like it’s easy to create identities, establish credit lines with no intent to repay, and propagate bad money into this system. It only takes one bad actor to corrupt the chain of mutual credit. From the documentation on the website it’s not clear at all how it handles even simple adversarial conditions like this. The fallback seems to be that you can limit what you are willing to lose by only establishing mutual credit up to a certain amount with each trusted party.

If a store doesn’t have a direct relationship with me it has to initiate a payment between an arbitrary number of intermediaries in order to fulfill the credit. Anyone have more insight into the practical application of mutual transitive credit?

[realcr]

Hey, interesting questions. Let me try and answer.

> I’d really kind to see a much more concrete specification

The best I can show you at this point is here: https://docs.offsetcredit.org/en/latest/theory/mutual_credit... This document is far from a full mathematical proof of safety, but it shows how things work. I expect the protocol to change in the next months, so I didn't want to be too detailed about the current protocol. Just to be sure it is known, Offset is open source, and you can find the full schema of communication here: https://github.com/freedomlayer/offset/tree/master/component...

> It feels like it’s easy to create identities, establish credit lines with no intent to repay

You can in fact create as many new identities as you wish with Offset, however, an identity doesn't worth much without established credit lines. Establishing a credit line requires human intervention. You will not be able to trick your human friend into adding your multiple identities of yourself as new credit lines to his Offset client. In other words, what protects you from Sybil attacks here is real world relationships with people.

If you ever decide to open your own "hub" or "bank" with Offset, giving credit lines to many strangers, you might want to have extra security, like maybe asking for their id card, or asking for some kind of collateral. But if the people you arrange credit line with aren't strangers, I don't think you have a real issue here.

> It only takes one bad actor to corrupt the chain of mutual credit

A bad actor can only compromise his direct "Offset friends", not a whole chain. When you set up your Offset node and add credit lines to your direct "Offset friends", you have to set up credit limits. Those credit limits limit how much money you can lose if any of your friends defaults. You can never lose more money than what you set up as your credit limits. If a friend of your friend defaults, your friend loses the money, not you.

> If a store doesn’t have a direct relationship with me it has to initiate a payment between an arbitrary number of intermediaries in order to fulfill the credit

Offset does this automatically for you. You don't really need to worry about this during the payment.

I might have missed something with my answers. Please tell me if you think something is missing!

[mangodwango]

I think what I’m missing is how a default works in this instance. If I establish a 200 unit mutual credit line with someone, spend 200, what does a default look like? Is there some time period in which I have to pay it back? Without collateral it seems that there isn’t a way to enforce payment.

If I buy a good, from someone accepting offset do they pay me back in credit the value of the good that they deliver? Thus netting us back to zero?

Thanks for answering my questions.