Slashing

This documentation describes the slashing mechanism that carries about punishments on validators and their delegators.

As secure of dfinance network depends on validators, fewer performance validators or attackers validators should be punished.

Each active validator has to pre-vote each new proposed block and also propose to block himself when his time comes, this is how works Tendermint. If a validator doesn't sign an approved block or miss his proposed round, such validator could be slashed (because of compromises network security).

More about network security you can read in Tendermint documentation and other links we provide in More section. Right now let's see how the validator could be slashed.

To see slashing commands use dncli slashing module:

# To see query commands.
dncli q slashing

# To see transactions commands.
dncli tx slashing

Slashing parameter described in genesis blocks, you can look at them:

dncli q slashing params

Current mainnet configuration looks so:

{
  "signed_blocks_window": "100",
  "min_signed_per_window": "0.500000000000000000",
  "downtime_jail_duration": "600000000000",
  "slash_fraction_double_sign": "0.050000000000000000",
  "slash_fraction_downtime": "0.010000000000000000"
}

Where:

• min_signed_per_window - the percent of blocks must be signed by the validator during blocks window, currently 50%.

• signed_blocks_window - size of blocks window, currently 31 blocks.

• downtime_jail_duration - jail duration while validator can't send unjail transaction, currently 600000000000 nanoseconds (10 minutes).

• slash_fraction_double_sign - the percent of stake that validator/delegator loses in case validator double sign block, currently 5%.

• slash_fraction_downtime - the percentage of stake that validator/delegator loses in case of validator downtime.

Important: slashing affects only sXFI delegations, LPT balances can't be slashed.

If validators slashed for downtime (missed signatures/proposals), validator and his delegators loose part of their stakes (see slash_fraction_downtime), also, such validator will be jailed, after jail period (see downtime_jail_duration) validator can send transaction to unjail himself. While the validator jailed, he can't propose/sign new blocks and participate in the consensus at all.

If validator double sign block, what's much more critical than downtime, then validator and his delegators will lose part of their stakes (see slash_fraction_double_sign), also, validator becoming jailed forever, and tombstoned - removed from validators list and can't participate in the consensus at all anymore.

To see your validator slashing statistic, use dncli:

dncli q slashing signing-info [validator-conspub]

Where:

• [validator-conspub] - is consensus public key of validator, can be found in the output using querying validator commands, like dncli q staking validators.

Unjail

If your validator slashed for downtime, it will be jailed. This is a period when validators can't produce blocks and participate in consensus. To become active again, a validator must send unjail transaction. Such a transaction can be sent only after the jail period is completed (see downtime_jail_duration), currently, it's 10 minutes.

To send unjail transaction use dncli:

dncli tx slashing unjail --from [account]

If the transaction is processed successfully, your validator will be unjailed.