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

@Kubuxu @lucaniz @irenegia @nicola @rosariogennaro Problem The current interactive PoRep protocol (PreCommit + ProveCommit) requires to seal and keep a buffer of 12 layers (11 SDR layers + 1 data l...

github.com

• ✨FIP-0059 (Synthetic PoRep)

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
• Delete ~11 layers of the SDR graph and keep the Synthetic Challenge Superset only
• Handle the transfer of synthetic challenges between sealing (i.e. challenge generation) and proof creation (ProveCommit)

Audit

• We need an internal audit/review of both theory and implementation - It can be done right after the proofs implementation

Next steps