Penalties

The rewards described earlier incentivize desired validator behaviors. The penalties below exist to deter unwanted validator behaviors:

Double Signing Penalty

This penalty triggers when a validator signs two different blocks at the same time (i.e. attempts a double spend attack). If double-signing is detected, then the violating validator will be penalized with:

• Burned FRA
  • burn 5% of FRA staked at validator

               - i.e. if validator staked 100 tokens, then 5 FRA will be burned
• Unbonding
  • all FRA staked (including FRA delegated to validator) are unbonded
  • the unbonded FRA can't rebond to another validator for 21 days.

Unavailability Penalty

This penalty triggers when a validator is offline too often for a certain number of blocks. Since the availablility of validators to contribute to voting is critical to securing a PoS blockchain, highly unreliable validators must be punished when they fall below a minimum performance threshold (aka unavailability threshold).

The unavailability threshold is defined as 95% missed blocks in last 10k blocks (~16hours). If a validator's availabilty to compute consensus falls below the unavailability threshold, then 0.1% of FRA staked by the validator is burned as a penalty.