A Brief Intro to Lachesis Consensus Engine

Quan Nguyen
2 min readOct 28, 2020
  1. What is Lachesis?

Lachesis protocol uses a DAG-based asynchronous non-deterministic algorithm to achieve practical Byzantine fault tolerance (pBFT). As introduced in our ONLAY paper, we introduced the use of graph layering and root graphs for faster root selection in Lachesis consensus protocol. With the assigned layers on the evolutionary DAGs across the nodes, the protocol achieves deterministic topological ordering of finalized event blocks in an asynchronous leaderless system.

StakeDag is the our recent innovation that leverages participants’ stake as validating power to achieve practical BFT in a leaderless asynchronous system. StakeDag protocol extends our Lachesis protocol to use layer assignment on the DAG to achieve quick consensus with a more reliable ordering of final event blocks. The benefits of StakeDag are two fold. StakeDag protocol is fair because every node has an equal chance to create a new event block. It has less vulnerabilities than PoW, PoS and dPoS.

Interested readers can find more details in our technical reports:

2. What is Fantom’s Opera mainnet?

Lachesis is the core engine running our Fantom’s Opera mainnet. Our mainnet allows users to deploy and use smart contracts, those that are compatible with Ethereum’s EVM.

3. How’s about the speed?

Node’s performance can depend on other factors such as how fast EVM can execute the transactions that are finalized.

What if the execution time of transactions are excluded? In that case, it’s obvious that one can measure the actual speed of the consensus engine.

Our experiments show that it can achieve up to 10k TPS (yes, 10k). It’s achieved on separate AWS nodes running medium specs.

For more details, please wait for the next posts !

--

--

Quan Nguyen

Quan Nguyen is interested in R&D on Blockchains and DLT. He is currently the CTO at Fantom Foundation. His background is Cloud, Web Apps, InfoVis, PL, VM.