(public) Blockchain

Blockchain is a continuously growing list of records, called blocks, which are linked and secured using cryptographic algorithms. Each block typically contains a hash (a link to a previous block), a timestamp as well as transaction data. Full nodes validate all the transactions, but they can’t settle the disagreements in which order they receive them. To prevent double-spending, the entire network needs to reach global consensus on the transaction order. It achieves this by using centralized parties or a decentralized proof of work or proof of stake algorithm (and its derivatives).

It’s important to understand that your local blockchain node won’t allow anything that is not “valid” (pre-defined consensus rules), even if the longest chain says otherwise.

Contrary to popular belief due to aggressive marketing, blockchains are not a good solution for storing data. Each piece of information that you store in the blockchain sits in hundreds or more nodes (more than 100 000 in case of the Bitcoin), making it very costly. This is why the Iryo Network doesn’t store data on blockchain but uses blockchain to ensure the transparency of transactions.

Some projects pretend to be using blockchain by using ’private chains’ which are usually just re-branded databases. Private chains use some elements of blockchain technology but miss key elements thereof like the oversight offered over the validity of the stored data.

Public blockchains are mainly useful for two things; value transfer (including initial creation and distribution) and trustless timestamping of the messages.