Scalability, Performance and Robustness #187 Milestone 6: KMS Cost Milestones (KM)

Milestone 6: _KMS Cost Milestones (KM)_

• Focus: Each message across the Canton Network carries the signatures of the involved nodes (submitting and delivering node). The keys used for such signatures should be kept in a KMS for security reasons. Cloud KMS systems have limited bandwidth and incur costs per request. By introducing session signing keys, this cost overhead and performance penalty can be reduced such that on-demand, in-memory held signing keys can be used temporarily, while the HSM key remains the authoritative, but infrequently used key.
• Estimated Delivery: July 1st, 2026
• Deliverables / Value Metrics:

- Functionality is integrated into Canton as a configurable option, including public documentation on usage and trade-offs. - HSM cost reduction by at least 90% for signature operations confirmed by DA SV ops team. This is to be measured relative to Splice 0.5.12 for equivalent TPS numbers. - Public documentation extended

| Milestone | Code | Payment | Acceptance / Trigger | |-----------|------|---------|----------------------| | 6 | KMS | 880,000 CC | Upon final release and acceptance |

_Originally posted by @pedrodneves in https://github.com/canton-foundation/canton-dev-fund/issues/187#issuecomment-4350406814_