and its most prominent application, the digital currency Bitcoin, were introduced in 2009 when cryptographer and computer scientist Satoshi Nakamoto published technical protocols that enable peer-to-peer transfer of digital assets. As the internet allows us to digitally transfer information, so the blockchain allows us to digitally transfer items of worth. Some have christened it “The Internet of Value.”.
At its most basic, the blockchain is a decentralized digital ledger. The protocols that govern it guarantee security, transparency, authenticity, and credibility. Trust is built into this 'machine.'
Encrypted transactions are initiated and accepted peer to peer. There is no financial middleman or bank that establishes trust between the parties. Instead, trust is established through the decentralized distributed ledger that is visible to anyone within the network.
When a transaction is initiated, this worldwide network of computers race to validate the transaction by solving complex algorithms. When the network reaches consensus that the digital ledger reflects that the transferring party actually has the asset to transfer, the transaction is validated and executed. And the digital ledger is updated, simultaneously, across the network. Anyone with the necessary computer power can participate in the verification process (aka become a network “node”).
The network is able to validate, timestamp and clear a transaction instantly because that activity happens immediately within the digital ledger itself, not between institutions. After the transaction is cleared, the network cryptographically links it to the prior transaction and publishes them in blocks. Each block is linked to the previous block and so an immutable chain is established. (Hence, the name blockchain technology.) No information in a block can be altered without changing all of the blocks prior to it, making it virtually impossible to hack.
The protocols of blockchain technology ensure immutable trust. Security is guaranteed through encrypted transactions that are pseudonymous and sealed into blocks. Transparency is ensured through the open, public decentralized ledger that anyone can view. Authenticity and credibility are established through a permanent, unalterable record of events.
Jenny wants to send Mark $100
The transaction request is sent to every node in the network.
The nodes reach consensus that Jenny has the $100. The transaction is approved.
The money moves on the digital ledger and the transaction is sealed into a block
The block is cryptographically and permanently linked to the previous blocks of transactions.
It’s counter-intuitive to think that a decentralized, distributed ledger is more secure than one tightly controlled by one entity in one place.
However, a centralized institution is actually more vulnerable to hacking because a perpetrator need only creep into one main system, as we have so alarmingly learned with the hacking of VISA, JPMorgan Chase, Target and others. A single point of control is also a single point of failure that can expose companies and their customers to disastrous security breaches.
Distributing the blockchain digital ledger across tens of thousands of participating nodes who are anonymous protects the data. It’s impossible to hack all of the nodes at one time. And if any one node is attacked, the intrusion can be detected by the rest of the nodes and the activity associated with the attack invalidated.
There are two basic types of blockchains: public and private. A public blockchain is just that: open to everyone and anyone who wants to transact and/or verify as part of the network. It is permissionless, meaning there are no barriers to participation. A private blockchain is one that is restricted within a company or limited to a group of cooperating companies. It is permissioned as one needs credentials to participate. There are many public and private blockchains acting simultaneously and independently of each other.
Established financial institutions and large corporations are enamored of blockchain technology and its potential to help cut costs and increase efficiencies. They are, however, pursuing the development of private, or permissioned, blockchains as opposed to a globally open publicly distributed ledger.