<aside> 👨‍🚀 This is a short outline of features and changes needed to ship Synthetic PoRep

</aside>

Intro

• Between PreCommit and ProveCommit SPs have to bring over almost 400 GB for 150 epochs.
• We want to lower down this storage requirement by 90%+ reducing it to less than 25 GB.

Relevant docs/links:

• https://github.com/filecoin-project/FIPs/discussions/603

No Buffer PoRep: Removing 10 layers storage between PreCommit and ProveCommit · Discussion #603 · filecoin-project/FIPs

• FIP-0059 (Synthetic PoRep)
• https://github.com/filecoin-project/FIPs/pull/627

Component implementation breakdown

Actors

• Add a new type of PoRep (Synthetic one) co-existing with the current one

Proofs

• New: Synthetic Challenge generation
  • Add a separate step after PC2 which generate the Synthetic Challenges Superset (245k vanilla proofs)
  • Audit
  • Implementation
• New: write new challenge selection method for challenges to be selected among the Synthetic Challenges Superset
  • Audit
  • Implementation
• C1 with the synthetic challenge needs to select challenges from the Synthetic Challenge Superset and not accessing the 11 layers buffer
• Exposed APIs via Filecoin Proofs and FFI

Lotus

• Allow SPs to select which type of PoRep proof they want to use
• Run the Synthetic Challenge Generation step if SP opts into it