Peras probability calculator

Explore the safety implications of Peras protocol parameter settings.

Commencing after a boosted block, the adversaries attempt to build a private fork that is longer then the honest chain. If the adversaries succeed, they reveal their chain so that honest parties abandon the honest chain they built, adopt the longer adversarial fork as their preferred chain, and build blocks upon it. Any blocks and transactions that were on the abandoned segment of the honest chain are rolled back.

Scenario

Fraction of adversarial stake (%/100): ⓘ

Protocol parameters

Boost (B, in blocks): ⓘ

Round length (U, in slots): ⓘ

Certificate expiration (A, in slots): ⓘ

Chain ignorance (R, in rounds): ⓘ

Cooldown period (K, in rounds): ⓘ

Block selection offset (L, in slots): ⓘ

Mean committee size (n, in nodes): ⓘ

Quorum size (τ / n, in %/100): ⓘ

Active slot coefficient (f, in 1/slot): ⓘ

Security parameter (k, in blocks): ⓘ

Performance metrics

Probability of a rollback after one boosting: ⓘ

Probability of a rollback in first U+L slots: ⓘ

Probability of a rollback after surviving U+L slots: ⓘ

Probability of a round not reaching quorum: ⓘ

Protocol						Scenario	Probability
B	U	L	n	τ / n	f	Adversary	Rollback after one boosting	Rollback in first U+L slots	Rollback after surviving U+L slots	No quorum