FIPXXXX: Introducing sealerID

FIPS/fip-xxx-sealerid.md

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+---
+fip: "xxx"
+title: Introducing SealerID
+author: nicola (@nicola), irene (@irenegia), luca (@lucaniz), kuba (@Kubuxu)
+discussions-to: https://github.com/filecoin-project/FIPs/discussions/890 
+status: Draft
+type: Technical
+category: Core
+dependency: FIP0090
+created: 2023-04-18
+---
+
+
+
+# FIPXXXX: Introducing sealerID
+
+
+## Simple Summary
+
+This adds the notion of `sealerID`, which is used in the sealing process of NI-PoRep. In particular:
+* We add a new actor, the Sealer Actor so that SealerIDs can be registered;
+* `sealerID` can be used to create `ReplicaID` by parting running the SDR labeling algorithm;
+* `sealerID` is added to the parameters of the method `ProveCommitSectorsNI`.
+
+
+
+## Abstract 
+
+With the current protocol, the party that creates the `ReplicaID` needs to use the same `minerID` that will be used for PoRep verifications. This implies that “pre-sealing” sectors is not a viable option: no sector can be sealed (ie, replica created) ahead of time, before knowing the identity of the miner actor who will own it. To enable this scenario, we introduce the concept of `sealerID` to be used in place of the `minerID` only during sealing.
+
+
+## Motivation
+
+We consider the scenario where Storage Providers want to delegate some of their activities to external parties that offer competitive services at lower costs.
+
+In particular, we call **Sealing-as-a-Service (SaaS) Provider** an entity that runs all PoRep operations (labeling the graph, column commitments, MT generation, vanilla proofs and SNARKs generation) needed to get a replica and onboard the sector that contains it.
+
+The SaaS then transfers the replica and the proofs to a **SaaS Client.** This is an SP that will onboard the sector with the replica R (ie, call a ProveCommit method) and will be responsible for storing R and proving validity of the corresponding sector (ie, running window- and winning-PoSt), and/or adding data to the committed capacity sector via SnapDeals.
+
+### Addressed issues
+
+1. [solved already] With interactive PoRep the SaaS Provider and Client needs coordination and agreement (therefore trust) about the intermediate interaction with the chain (ie, sending commR on chain) and locking down PCD (PreCommitDeposit). This is resolved by using NI-PoRep [FIP0090](https://github.com/filecoin-project/FIPs/blob/master/FIPS/fip-0090.md) that requires no chain interaction and no deposit.
+2. [solved by this FIP] Even with NI-PoRep, some coordination between the SaaS Provider and their client (SP) remains. Indeed during the labelling phase the SaaS Provider creates `ReplicaID` and for this it needs to use the `minerID` and `sectorNumber` from the SaaS Client who will receive the replica to be stored. If these values are not correctly used then the SNARK proof will not be valid. This means that a SaaS Provider needs to “wait” for the request (and info) from a SaaS client to seal sectors. In other words, this prevents a SaaS Provider from sealing sectors in advance using its HW at max capacity (and therefore reducing sealing cost for everyone).
+
+
+## Specification
+
+1. We add a new type of actor: the Sealer Actor;
+   - This can be a “disposable” actor, no need for an owner key. If something bad happens, create a new id. This is okay because no tokens are locked for this actor;
+   - The Sealer Actor is a multiple instance type: Anyone can create a Sealer Actor and `sealerID` will simply be the actor ID. This ensures that the list of sealerIDs is disjoint from the list of minerIDs.
+   - The new actor needs `sectorNumber` facilities: There is a map `sealerID -> [sealerSectorNumber]` in the state (that is, we have a list of used sector numbers for each sealer); Concretely this sector number list would be a bitfield as is the case of the miner actor.
+
+2. Modify the method `ProveCommitSectorsNI` to accept the sealerID to create `ReplicaID` .
+    - Add a new field to `SectorNIActivationInfo` for passing the `SealerID`:
+      - if empty, use the the minerID when creating the `ReplicaID`
+      - if a value is passed, use this for `ReplicaID` (in the place of `minerID`)
+    - Add a new field to `SectorNIActivationInfo` for passing `SealerSectorNumber`:
+      - again, if we are in the case EMPTY_SEALER_ID, then `sealerSectorNumber` could either be ignored or enforced to be 0, otherwis eit is used for `ReplicaID`;
+      - note that the miner actor identifies sectors internally using a `SectorID` structure with a `{minerID, sectorNumber}` pair. This is replaced by `{minerID, sectorNumber, minerSectorNumber}` where last value can be 0.
+
+
+3. [optional/future] ACL (the sealer has control on who can activate their sealed sectors)
+    -  Store in the Sealer Actor another address: this is an address to a proxy contract that can be used to implement ACL. When an SP onboards a sector, then call to the Sealer Actor. If the ACL is enabled, then call the ACL contract. 
+    - TODOs:  write the concrete interface to the ACL contract (eg, `check(sectorNumber, minerID) bool`) ![Sealer ID](https://github.com/filecoin-project/FIPs/assets/23217773/4852d5eb-6c81-4fc7-9f7e-dd7a351ed943)
+
+
+
+## Rationale 
+
+The design aims to 
+* Minimize changes with respect to the status quo, particularly maintaining `ReplicaID` as a unique identifier within the entire Filecoin ecosystem;
+* Provide future programmability. In particular, as regards the access control feature we decide to implement it using a proxy contract (instead of implementing it directly in the actor) in order to have the possibility of the final users (ie, SaaS providers) to personalize it. 
+
+
+## Backwards Compatibility
+
+TODO
+
+
+## Test Cases
+
+TODO
+
+
+## Security Considerations
+
+* *Front-running Attacks* :
+  * These are not rational (ie, termination fee will be paid by the front-runner SP);
+  * If needed, we can implement ACL (see point 3 in the spec) to make this kind of attacks impossible.
+
+* *Double spending a Sector*: TODO (add a signature done by sealer to make “double-spending” sectors detectable on chain);
+
+
+
+## Incentive Considerations
+
+The proposed change (ie, introducing the sealer id to completely decouple computation-heavy tasks for onboarding sector from the sector ownership) allows SaaS providers to seal sectors independently from the current demand and therefore to use their hardware at full capacity. This incentivises the creation of a market for CC sectors and lower the SP cost for onboarding CC sectors, which can later on be upgraded to useful storage via the SnapDeal protocol (`ReplicasUpdate3 `method).
+
+
+## Product Considerations
+
+Having SaaS providers and CC-sector markets lower the entry barrier for SPs to join the Filecoin network. Indeed, with this service in place SPs do not need to have the HW to run the PoRep step in house. Note that the HW for running winning- and window-PoSt is still needed.
+
+
+## Implementations
+
+TODO
+
+
+## Copyright Waiver
+
+Copyright and related rights waived via [CC0](https://creativecommons.org/publicdomain/zero/1.0/).