Specify how multiple TREs should connect to each other to support federation

[manics]

How should two K8TRE compatible TREs connect to each other to support federated queries (or data transfers)? E.g.

• Limit access by IP and using TLS certificates
• Point-to-point VPNs
• XRoad or Director's connector

What should be added to the K8TRE specification, and what should the reference implementation provide?

[machintim]

May be able to take this to the workshop for the Federation Pillar in SATRE planned for the UK TRE community in Leeds.

[manics]

Good idea! It'd be good to hear what the wider community thinks. Should everything be double encrypted (VPN between sites, and individual network connections are encrypted) or is a single layer of encryption with authentication/authorisation in the application layer enough?