Referencing VC

[vivienfan]

Related issue: #374

Replacing directly embed credential with a hashlink which points to the hosted VCs

Hashlink is prefered over Evidence and Related Link because:

1. it makes sure the data being referenced is the same

   • in the case of Events, Products should stay the same (ie, size, amount, manufactuer, etc.)
   • Hashlink makes sure the content returned by the link is the same as when it's generated, otherwise the hash would change
   • Evidence and Related Link can only meet this requirement if reference/target is Hashlink

2. it describes the relationship between Products and Events in a dry way

   • in the case of Transform Events, there are 2 types of Products - newly created & consumed/used products
   • Hashlink is replacing the directly embed credential in the structure, which already describes the type of Products
   • Evidence does not describe the type of credential being referenced
   • Related Link has a field LinkRelationship to meet this requirement, but the solution is more complicated and harder to read

[nissimsan]

This does not look like a products definition?

[nissimsan]

@vivienfan, so the intention is because there are multiple events for the same product, you don't want to repeat the product data? That's a good intention.
Signing a link doesn't seem very valuable, though. I would suggest signing over the product's id instead?

[vivienfan]

@vivienfan, so the intention is because there are multiple events for the same product, you don't want to repeat the product data? That's a good intention. Signing a link doesn't seem very valuable, though. I would suggest signing over the product's id instead?

@nissimsan, the link here would be a Get request endpoint which returns the product VC, and the hash would make sure the product is the exact same product when the event VC was issued.

[nissimsan]

@vivienfan I see. That's a new pattern, but I won't stand in the way. :) Thanks for elaborating.