Data storage

Questions
1
  • Does Canton stores data in participants nodes or everything is stored on there underlying blockchain?
  • In the case Canton already stores the data:
    What is stored on the underlying blockchain ?
    Does every nodes have exactly the same datas ?
  • If there is a transaction which is private between two parties are they the only ones storing the datas of this transaction or everyone store it but only them can see it?
2

Hi @TanguyLauc :wave:

All transaction data relevant for a particular party is stored on the participant node that serves it/where it’s located. In that sense all transactions are private as only data relevant for a party that is involved in a transaction is stored on the node.

Having said that there are some general trust assumptions between different services running on a node as @Ratko_Veprek points out here. Going over the example topology from Canton’s Getting Started guide provides more info as well as the basic example of how transactions are executed in Canton

3

Thanks @nemanja for the response. Just adding one minor thing: the data is dispatched from one participant to the other participant through the domain, so maybe on the underlying blockchain if that domain is using one. However, the data is end-to-end encrypted such that only the involved participants will be able to decrypt it.