Fuel Labs, a research group focused on sustainable scaling for Ethereum with optimistic rollups, has announced that the first public testnet for Fuel, an efficient, scalable, and secure optimistic rollup chain on Ethereum is now live and its code has been open-sourced.

Testnet v0 is a series of short-lived testnets that examine stability and performance. The team hopes to implement a series of improvements over the coming months. Launch of a long-term Fuel v1 testnet is planned to be implemented by the end of Q1 2020.

Features for v0

An optimized version of minimal viable merged consensus (aka optimistic rollup) that is more responsive and cheaper than the original design, while retaining identical security guarantees. By using Yul instead of Solidity for low-level memory manipulation, fraud proofs can execute in under 1M gas.

With cheap fraud proofs, security is highly-resilient against chain congestion attacks, unlike Plasma and state channel networks. As with any properly-design optimistic rollup, the only way to attack it is for miners to conduct a week-long 51% attack on the main chain — highly visible, easily attributable, and impossible in practice for a chain as important and secure as Ethereum.

Transactions on Fuel can also send funds to HTLCs, which allow for atomic swaps. When combined with a liquidity provider network, users can instantly withdraw their funds, potentially in as quickly as a single block. This also opens another door for liquidity providers to earn returns on their ether and tokens in a trustless manner.

UTXO data model similar to Bitcoin over the accounts data model. This means scalable and completely non-custodial exchanges can be built on top of Fuel, with only order matching happening off-chain.

State and state access are completely off-chain, making optimistic rollup sustainably scalable. Uncontrolled state growth is the largest problem and bottleneck facing Ethereum today.

Completely tokenless. Fuel is fully permissionless and non-custodial. Their block production model is a priority aggregator.

Support for instant trusted transactions: if the receiver chooses to trust Fuel until the next block, they can accept a received transaction as valid. A signed cryptographic proof will be received from both the transaction sender and Fuel, so any double-spending would be provably attributable.

“This is just the beginning. We have big plans for the future of Fuel and the promise of highly-scalable stablecoin payments — and other use-cases — it brings to the table. If you’d like to support our R&D efforts, consider contributing to our Gitcoin grant.”

– The Fuel Labs Team