CPS-???? | Quantum secure Cardano settlement layer

[perturbing]

This CPS discusses the technical details of making the Cardano layer one settlement layer quantum secure. The scope of this work is limited by the consensus side of the PQC discussion.

Rendered version

[hjeljeli32]

Thanks @perturbing for kicking this off 🙏

I added a couple of comments on the Problem and Goals sections to try to structure the discussion around threat model and priorities.

For the next steps, I think it could be interesting to expand on:

• Use cases (especially from a consensus / protocol perspective)
• You and Gamze have a very strong view on the use cases and system aspects.

Of course, very open to feedback on my suggestions above 👍

[hjeljeli32]

Goals (proposal)

Following the threat model above, we could define the following high-level goals:

• Ensure post-quantum security of the root of trust

  • Cover signature schemes, VRF, and delegation mechanisms
  • Favor mature, well-studied, and standardized constructions (e.g. NIST PQC)

• Optimize for practical constraints (latency, bandwidth, storage)

  • Carefully evaluate trade-offs between signature size, public key size, and verification cost
  • Prefer schemes that minimize impact on block size, propagation, and validation

• Maintain acceptable network performance

  • Ensure block production, propagation, and validation remain within acceptable limits
  • Allow for potential adaptation of protocol parameters if needed

• Support crypto-agility

  • Enable smooth and incremental migration of cryptographic primitives
  • Minimize disruption to existing infrastructure and avoid costly future migrations

Do you think it makes sense?

[rphair]

@hjeljeli32 thanks for joining the discussion; I look forward to seeing your & the co-authors' continuing work on this.

Just so the CIP editors (@perturbing among them) can track when this will be ready to introduce into review (by default, only when taken out of Draft status): when you approved this in #1175 (review), what were you approving? (since there is currently no content in the CIP)

[hjeljeli32]

@hjeljeli32 thanks for joining the discussion; I look forward to seeing your & the co-authors' continuing work on this.

Just so the CIP editors (@perturbing among them) can track when this will be ready to introduce into review (by default, only when taken out of Draft status): when you approved this in #1175 (review), what were you approving? (since there is currently no content in the CIP)

Thanks for pointing this out @rphair. I approved by mistake and did not mean to signal that the draft is ready for review.

At this stage I only intended to leave feedback on structure and content. Please disregard the approval; @perturbing or another editor can dismiss it if needed.