keychain to keep reputation

[grunch]

As we implemented nip59 to Mostro which will allows more privacy to users, I'm thinking how to keep privacy and still allow users to be rated and share their reputation.

Here's an idea that we can discuss here:

Clients will always use a new ephemeral key for each new order, the user who wants to maintain reputation can send an event to Mostro signed with the last ephemeral key used to update their rating.

Example:

• Alice uses the automatically generated key abc to create a sale order
• Bob takes the order, they finish the operation
• Each one rated their counterparty's ephemeral pubkey

later:

• Alice wants to make another sale, the client automatically generates the key xyz
• Alice's client automatically sends a message inside a gift wrap event to Mostro signed with the key xyz and the internal content signed with the key abc, this way Mostro knows that the user of xyz is also the user of abc
• Alice creates the order with the key xyz and Mostro shows the reputation obtained with abc
• Carol takes the order
• They finish the operation
• Each one rated the counterparty's ephemeral pubkey (xyz in case of Alice)

Mostro only need to save the last Alice's pubkeys to keep the chain

[bilthon]

If the ultimate objective is to selectively reveal one's identity to mostro (and only mostro) in order to build a reputation, it seems to me like an overkill to do this chain. A similar result would be obtained if the user were just to use always the same key at the seal level.

[grunch]

Exactly, the intention of publishing the reputation in nostr is to allow interoperability between Mostros

[bilthon]

My approach was based on an equivalence principle—thinking that, from Mostro's perspective, it’s essentially the same whether clients use a chain of keys to represent their identity or a single key consistently. However, that equivalence breaks down if you want to allow clients to port their reputation across different Mostro instances. In that case, you do gain some privacy benefits by constantly switching keys.

The idea of users porting their reputation across Mostro instances is a use case I hadn’t considered. But I think you should be cautious with this approach, as it could quickly become an attack vector. Anyone can run a Mostro instance, and since keys and signatures are cheap to produce, allowing users to transfer their reputation from any other Mostro instance could open the door for people to game the reputation system.

I don’t want to extend this conversation too much. If you want to go with the chain of keys approach, I think it is indeed a more flexible solution and allows for these kinds of features to be introduced. But if the goal is to restrict reputation to a single Mostro instance, then it’s basically equivalent to always using a single key. In that case, a KISS solution is always preferred.

[Catrya]

Anyone can run a Mostro instance, and since keys and signatures are cheap to produce, allowing users to transfer their reputation from any other Mostro instance could open the door for people to game the reputation system.

I hadn't thought about that case, but you're right. We would have to think about whether it can be avoided and at the same time maintain a global reputation, or not.

[grunch]

I hadn't thought about that case, but you're right. We would have to think about whether it can be avoided and at the same time maintain a global reputation, or not.

I had this on mind since the beginning, one of the final steps is to implement a reputation system for users to rate Mostros, Users cannot blindly trust from one day to another in a Mostro, trust must be building each

[Catrya]

I had this on mind since the beginning, one of the final steps is to implement a reputation system for users to rate Mostros, Users cannot blindly trust from one day to another in a Mostro, trust must be building each

And what is the idea? That Mostros with more reputation contribute more to a user's reputation than less used Mostros?
Or that in a user's reputation show something like a percentage of how much he accumulated in each monster he used? For example: 4.5 stars, from there 75% he accumulated in Monster X, 20% in Monster Y, and 5% in Monster Z?
Or something else?

[Catrya]

If the user wants to change clients but keep their reputation, what would it be like?
Would the client 1 provide the last private key with reputation and when entering the new client, the client 2 would sign the content of the message sent to mostro with that key and the signed message with the new key generated? Or is this not possible?

[grunch]

that's the main idea, to move from clients you only need to export the last private key used and sign with that one from the new client

[grunch]

closing this dicussion in favor of #396