Definition
A bribery attack subverts proof-of-work consensus not by owning a hashrate majority but by renting one. The attacker offers miners out-of-band payments, inflated rewards, or smart-contract bounties to mine the branch the attacker wants. If enough rational miners accept, the attacker briefly commands a majority of hashrate and can attempt the same outcomes as a 51% attack, including reordering blocks, censoring transactions, or executing a double-spend.
How Bribes Are Delivered
Bribery can take several forms: direct side payments to miners, a pool that simply advertises higher payouts to lure hashrate, or a fork that carries embedded bribe funds claimable by whoever extends it. More elaborate schemes use a smart contract on another chain that pays out only if a target transaction is reversed or a censorship goal succeeds, letting the attacker coordinate many miners trustlessly.
The Goldfinger Variant
A related extreme is the Goldfinger attack, where the goal is not direct profit on Bitcoin but the destruction of confidence in it. An attacker might use a contract that rewards miners in one cryptocurrency for degrading another, accepting a loss in order to damage a rival network. Bribery and Goldfinger attacks blur the line between economic and political motivation, which is why analyses stress that Bitcoin's security ultimately rests on the cost and coordination difficulty of renting hashrate, not on any single owner's restraint.
Bribery attacks connect to feather forking for censorship and to chain reorganization as the delivery mechanism. See also proof of work.
Track hashrate concentration in the pool centralization tracker.
In Simple Terms
A bribery attack subverts proof-of-work consensus not by owning a hashrate majority but by renting one. The attacker offers miners out-of-band payments, inflated rewards, or…