The consensus mechanism of Fantom blockchain.

What Is Lachesis (Fantom)?

Lachesis is the second of three main components of the Fantom stack. It’s a distributed ledger and smart contract platform, similar to Ethereum. However, it has several unique features that make it a very interesting project.
Lachesis is based on a Directed Acyclic Graph (DAG) structure, so it doesn’t use blocks for transactions. Instead, it uses nodes to verify transactions. 

Fantom is the world’s first DAG-based smart contract platform that solves the issue of scalability and confirmation time of the existing blockchain technology.

Fantom has been designed by a team of experts in the fields of Distributed Ledger Technology, mathematics, information theory, computer science, finance, and business strategy. The aim was to build a platform where developers can easily deploy their own smart contracts and dApps on Fantom’s high-performance and scalable blockchain infrastructure.

The fast-growing ecosystem of dApps on Fantom will have access to a wide range of tools that will further streamline the process of development. The platform has been architected from the ground up to be future-ready for mass adoption. The technologies used are open source and completely transparent.

Lachesis is Fantom’s aBFT consensus algorithm. The term “aBFT” stands for asynchronous byzantine fault-tolerant. It is an improvement on the popular PBFT algorithm, which is currently used by many blockchain projects including Hyperledger and Tendermint.

The primary difference between Lachesis and PBFT is that Lachesis allows for asynchronous consensus, while PBFT requires synchronous consensus. This means that the time between blocks can be constant (synchronous) or variable (asynchronous). The longest time between blocks in a synchronous network is equal to the time it takes to create a block. In an asynchronous network, it takes much longer than in a synchronous network to achieve consensus, as blocks can be created at any time.

Although there are some disadvantages to asynchronous consensus networks, they also have some advantages:

Asynchronous networks are more scalable than synchronous networks because they do not need to wait for all nodes to respond before creating new blocks. Scalability is important for many applications of blockchain technology, such as supply chain management and financial transactions. Asynchronous networks allow for faster transactions and more efficient use of resources than synchronous networks.

One of the most interesting features of Lachesis is that it uses a reputation mechanism called Proof-of-Stake Authority (PoSA). It’s a version of the Byzantine Fault Tolerance consensus algorithm that adds a reputation system to the process. The PoSA mechanism allows Lachesis nodes to vote on whether or not others are working honestly or not and penalizes those who aren’t by removing their right to validate transactions. Nodes can also earn rewards if they work properly, incentivizing honest behavior.

Lachesis is designed to be much more flexible than current blockchain consensus algorithms, allowing for faster block times and improved scalability.

The Lachesis protocol assigns each node in the network a weight that corresponds with the amount of stake they have. The weight of all the nodes in the network will always add up to 100% (or 1). This weight can be used to determine the probability that a node will be selected as an Event Creator (EC).