XDC - Data architecture

Hello Pierre,
Apologies for a delay in my response.
With any financial messaging, security, authorisation and compliance is central to the design and to this end, there is a place in the design for authorised observers.
This design is subdivided into the following domains:

• Identity Service
• The Layer 2 protocol
• The ISO20022 messaging schema - notably the PACS sub-schema

The Identity Service is a secured managed store of X509 certificates and well-known on-chain accounts. At present access to this service is managed by Impel.

The Layer2 channel protocol is at present a two-party model for secure, high-throughput and low-latency message exchange. The design has space for the facility to add more counterparties e.g. for authorised observers.

Specifically, for a bi-lateral transaction channel, authorized observers can be added such they have:

1. visibility of channel construction, linking back to the initiating on-chain transaction hash
2. intra-channel messages
3. the Merkle tree proof-of-delivery hashes and signatures
4. channel closures and final Merkle tree proofs

Finally, at the Gateway API level, messages are delivered with the counterpart signatures. These can be used by any internal Compliance and Audit facility to demonstrate provenance and to carry out payload analysis for reference and economic fields.