You’ve heard the term, but what on earth does it mean? Let’s start with the basics. A blockchain is a data structure that makes it possible to create a digital ledger of transactions and share it among a distributed network of computers. It uses cryptography to allow each participant on the network to manipulate the ledger in a secure way without the need for a central, often fee-charging authority.
Bitcoin and the mechanics of blockchain
If you are familiar with blockchain technology, it may be because of Bitcoin, the first app built using the platform in 2008. Bitcoin’s main premise is to digitally send payments between any two people or organizations without a third-party financial institution. Every time a transaction is made, it’s recorded on the blockchain ledger and each new block is tied to the prior ones via digital signature. Once a block of data is recorded on the ledger, it’s difficult to change or remove, and in order for someone to add a block to the chain, network members have to first ensure it’s valid.
A few key components underpin blockchain technology. First up is the network, which can vary depending on the organization setting up the blockchain. It might include everyone in the public domain (as in Bitcoin) or an exclusive group of known participants. The computers within each network are called nodes.
Then, there is the consensus mechanism, or the set of rules used to verify each transaction. In the Bitcoin blockchain, for instance, the consensus mechanism is called proof of work. Network participants run algorithms to confirm the digital signatures attached to blocks in order to validate new transactions. Once approved, transactions are packaged into a block. They are then re-distributed to all the nodes, which are responsible for ensuring that all records match.
For his article for the Wall Street Journal CIO Journal blog, writer Steven Norton consulted Guardtime, a company that sells blockchain-based products and services to organizations like Ericsson AB. Guardtime provided this example of a complex blockchain in action:
“Assume an organization has 10 transactions per second. Each of those transactions receives its own digital signature. Using a tree structure, those signatures are combined and given a single digital fingerprint — a unique representation of those transactions at a specific time.”
“Once validated, that fingerprint is stored in a blockchain that all the participants can see. A copy of that ledger is also sent back to each organization to store locally. Those signatures can be continuously verified against what is in the blockchain, giving companies a way to monitor the state and integrity of a particular asset or transaction.”
“Anytime a change to data or an asset is proposed, a new, unique digital fingerprint is created. That fingerprint is sent to each client node for validation. If the fingerprints don’t match, or if the change to the data doesn’t fit with the network’s agreed-upon rules, the transaction may not be validated. This setup means the entire network, rather than a central authority, is responsible for ensuring the validity of each transaction.”
Want more? Check out the full article on the QuickBase Fast Track blog.