TrueBit has quietly gone through a major upgrade, and Jason Teutsch and I are pleased to finally announce the official TrueBit 1.0 protocol, available on our project webpage. TrueBit’s fond and familiar “dispute resolution layer” still lies at the core of TrueBit’s construction, but we’ve wrapped it up inside of a new “incentive layer.” This new layer should both properly reward Verifiers and, in turn, force Solvers to behave correctly. Practically speaking, smart contracts with TrueBit can execute C++ code without running up against Ethereum’s gas limit. TrueBit itself is simply a smart contract, which means that we don’t need to introduce a hard fork, a soft fork, or disrupt legacy smart contracts to achieve full computing functionality.

Some more technical details:

For quite some time, the Ethereum community has known about the dispute resolution layer which Verifiers can invoke upon error detection. As a standalone system, however, the dispute resolution layer lacks incentives for Verifier participation. In TrueBit’s previous incarnation, if a Solver knew that a Verifier was watching closely, the Solver would not try to cheat. On the other hand, Verifiers receive little, if any, compensation for allocating their limited resources to watching Solvers closely. In this simple system, Verifiers only get rewarded when they identify Solvers’ mistakes, whereas their act of watching ensures that Solver mistakes never actually occur. This weird dynamic results in Verifiers inevitably becoming lazy over time and provides Solvers with opportunities to cheat.

The obvious fix for this laziness issue is to reward the Verifier each time she checks a solution. But if a solution does not contain an error, how can the Verifier prove to a smart contract, whose computational bandwidth is limited, that she did indeed check it? To solve this problem, TrueBit 1.0 introduces a “forced error mechanism” which forces Solvers to occasionally produce incorrect outputs. By detecting and reporting such “forced errors,” Verifiers prove to the system that they are still paying attention.

Please see our whitepaper for further details, analysis, and application ideas!