Lockstep protocol - Wikipedia

submited by

Style Pass

2024-04-29 15:30:05

The lockstep protocol is a partial solution to the look-ahead cheating problem in peer-to-peer architecture multiplayer games, in which a cheating client delays their own actions to await the messages of other players.[1] A client can do so by acting as if they're suffering from high latency; the outgoing packet is forged by attaching a time stamp that is prior to the actual moment the packet is sent.

To avoid this method of cheating, the lockstep protocol requires each player to first announce a "commitment" (e.g. hash value of the action); this commitment is a representation of an action that:

Once all players have received the commitments, they reveal their actions, which are compared with the corresponding commitments to ensure that the commitment is indeed the sent action.[2]

As all players must wait for all commitments to arrive before sending their actions, the game progresses as slowly as the player with the highest latency. Although this may not be noticeable in a turn-based game, real-time online games, such as first person shooters, require much faster reactions.