Module slashing

Dispute slashing pallet.

Once a dispute is concluded, we want to slash validators who were on the wrong side of the dispute.

A dispute should always result in an offence. There are 3 possible offence types:

• ForInvalidBacked: A major offence when a validator backed an invalid block. Main source of economic security.
• ForInvalidApproved: A medium offence when a validator approved (NOT backed) an invalid block. Protects from lazy validators.
• AgainstValid: A minor offence when a validator disputed a valid block. Protects from spam attacks.

Past session slashing edgecase:

The offences pallet from Substrate provides us with a way to do both. Currently, the interface expects us to provide staking information including nominator exposure in order to submit an offence.

Normally, we’d able to fetch this information from the runtime as soon as the dispute is concluded. However, since a dispute can conclude several sessions after the candidate was backed (see dispute_period in HostConfiguration), we can’t rely on this information being available in the context of the current block. The babe and grandpa equivocation handlers also have to deal with this problem.

Our implementation looks simillar to the grandpa equivocation handler. Meaning, we submit an offence for the concluded disputes about the current session candidate directly from the runtime. If, however, the dispute is about a past session, we record unapplied slashes on chain, without FullIdentification of the offenders. Later on, a block producer can submit an unsigned transaction with KeyOwnershipProof of an offender and submit it to the runtime to produce an offence.

Re-exports

pub use pallet::*;

Modules

benchmarking

pallet

The pallet module in each FRAME pallet hosts the most important items needed to construct this pallet.

Structs

BenchConfig

SlashValidatorsForDisputes

This type implements SlashingHandler.

SlashingOffence

An offence that is filed against the validators that lost a dispute.

SlashingReportHandler

Actual HandleReports implementation.

TestWeightInfo

Traits

BenchmarkingConfiguration

The benchmarking configuration.

HandleReports

A trait that defines methods to report an offence (after the slashing report has been validated) and for submitting a transaction to report a slash (from an offchain context).

WeightInfo