Creator
KubuxuCreated
Feb 9, 2022 12:34 PM
Project
Storage on-boarding
Stage
Still Valid
Authors: @Kubuxu, @Irene, @Nicola
Main Problem: Sealing is expensive (in terms of execution, since it requires expensive hardware)
Goals
- Decrease by half the GPU utilization
Intuition: Let’s decrease the cost of sealing
- Attempt 1: Reduce the SNARK load by removing SHA
- → too difficult, requires trusted setup, requires new PoRep
- Attempt 2: Off-chain PoRep verification with external network of challenger nodes
- → too difficult, but a good idea
- Attempt 3: Explore new ways to mine without luxurious hardware (utilize lower-end hardware in a better way)
- → feasible, but seems too difficult
- Attempt 3: Let someone else seal for you (will decrease the upfront cost, but won’t reduce the cost)
- → feasible, we are looking into it Off-chain sealing market design sketch
- Attempt 4: Decrease the security of PoRep (even more!) to decrease the number of challenge, to decrese GPU overhead
- → feasible, very simple to implement
High level idea:
- Decrease the PoRep security by decreasing the number of challenges, which decreases the number of SNARKs
- In order to guarantee security in the network we must increase PCD
- Having a higher PCD is an ok outcome
Pros & Cons
- Pros:
- ~90% of PoRep is SNARK generation, reducing the number of SNARKs will have a real impact.
- Cons:
- However, Snark technologies has improved of 10x during the past few years, if we believe the trend continues, then this solution might be not that useful
Formulas:
- How many challenges (hence how many SNARK proofs) do we need for bits of security? (reducing s)
: bits of security (today: 10)
: fraction of errors (today: 0.039)
https://www.wolframalpha.com/input?i=1%2Flog2(1-x)+x+from+0.039+to+0.08
- How much spacegap are we willing to give up? (by increasing x)