Hashgraph


Hashgraph is a distributed ledger technology developed by Leemon Baird, the co-founder and CTO of Swirlds, in 2016. It is an asynchronous Byzantine Fault Tolerance consensus algorithm that they consider capable of securing the platform against attacks. It does not use miners to validate transactions, and uses directed acyclic graphs for time-sequencing transactions without bundling them into blocks.

Concept

Several experts describe Hashgraph as a continuation of where the idea of blockchain begins while some consider it as an alternative to it, a technology known as first generation and typified by severe speed, fairness, cost, and security constraints. Some academics maintain it is less technically constrained than blockchains proper. The Hedera white paper co-authored by Baird explained that "at the end of each round, each node calculates the shared state after processing all transactions that were received in that round and before," and it "digitally signs a hash of that shared state, puts it in a transaction, and gossips it out to the community." Hedera Hashgraph is a public distributed ledger based on the Hashgraph algorithm which in 2018 raised $100 million at a $6 billion market cap.
Cornell Professor Emin Gün Sirer notes that “The correctness of the entire Hashgraph protocol seems to hinge on every participant knowing and agreeing upon N, the total number of participants in the system,” which is "a difficult number to determine in an open distributed system.” Baird responded that “All of the nodes at a given time know how many nodes there are.”