Hedera Hashgraph (HBAR) introduces trustless timestamping service
It's worth asking why and how time flies on distributed ledgers. Only then can you ask when.
Hedera Hashgraph has launched a mainnet consensus service, the Hedera Consensus Service (HCS).
In non-plain English, this means it's launched a service to synchronise the fair order of messages for distributed systems without relying on a centralised clock, allowing for verifiable timestamping of digital ledger transactions.
In plain English, this means you can tell when a transaction occurred, without trusting someone else to tell you when it occurred.
This is deceptively important, for two reasons.
Firstly, because anytime you have to place your trust in a third party, you're opening the door to things going wrong. Trusting third parties means things get unpredictable, and it means they're open to abuse, misuse, mistakes and all other kinds of misadventure.
So in a nutshell, this service means you can know that timestamps are correct, rather than needing to trust that timestamps are correct. This level of knowing is often referred to as trustlessness.
This goes to the second point – that just about everything relies on accurate timestamps.
"Stock exchanges, marketplaces, enterprise databases, and others all rely on having a trusted timestamp for each transaction," said Hedera Hashgraph co-founder and chief scientist Leemon Baird. "If the decentralised world intends to disrupt these spaces, it needs to be able to provide fair consensus timestamps, which show the time when the entire network received the transaction."
"Logging transactions in the exact order they occur is crucial to use cases across nearly every industry. HCS combines hashgraph's fast, fair, and secure consensus algorithm with the trust and governance of Hedera’s public network. It allows groups working together to then apply this trust and governance to their applications that need both trust and privacy."
Basically, what this development does is create a way for organisations to tap into Hashgraph's inherent trustless timestamping properties, even while interacting with each other on private networks off the side of the main Hashgraph network, to know, rather than trust, that other organisations' timestamps are correct.
It taps into the fact that all blockchains, and other distributed ledgers, run on timestamps. In a way, the sole purpose of any blockchain is to arrange transactions into the order they occurred, in a way that everyone can be sure is correct.
Hashgraph isn't technically a blockchain, but it's still a type of distributed ledger and the same rule applies. As the HCS whitepaper says: "Hashgraph's primary function is to calculate a fair order of transactions in a decentralised environment."
How time files
In a way, timestamping is how you make a decentralised computing network "aware" of the concept of time. You can't tell a distributed network to check a wall clock to see when a transaction happened, but as long as it's able to tell what order transactions occurred in, it's able to have a concept of the passage of time.
This is important because bad things can happen whenever timestamps go wrong or time can be tampered with. For example, if you want to accept a cryptocurrency payment, you need to ask "how much cryptocurrency does this person have right now?" If they have enough, you can accept the payment. In this case, right now means everything after the most recently-finalised transaction.
The crux of the problem, then, is how you can have an entire network reach agreement on the order in which transactions occurred, while accounting for factors such as latency, internet outrages and hostile network nodes, and while doing it quickly.
The way Bitcoin and many other blockchains "solve" this problem is by doing it really slowly, lumping transactions into blocks and requiring majority approval for everything.
If you think of the analogy of blockchains as having an organisational structure, Bitcoin and other "traditional" blockchains work as though employees have to collect all these timestamps and then pass them to a team of executives for final approval.
By contrast, Hashgraph works as though everyone in the organisation is simultaneously writing their own timestamps and approving other people's. Someone makes a decision and passes it on to their neighbours, who then tell their neighbours and so on, until everyone in the organisation has heard about the decision and knows when it originally happened. The reason this works is because the workers in this particular organisation can talk really, really fast.
Different underlying main-chain timestamping systems can be utilised in different ways. In this case, we can see that the Hashgraph system allows for trustless timestamping, while others don't.
For less-analogous and more detailed explanation of exactly how time flies on Hashgraph and HCS, you should probably consult the whitepaper.
Disclosure: The author holds BNB, BTC at the time of writing.