A blockchain is defined as a distributed database that can maintain an ever-expanding list of records (called “blocks”) without the need for a trusted administrator or a central server, instead relying on a peer-to-peer network collectively adhering to a protocol for validating new blocks.
Each block contains a time stamp and a link to a previous block.
By their design, blockchains are highly resistant to data alteration or modification so that data, once recorded, cannot be altered retroactively without the alteration of all subsequent blocks – and this would also require the collusion of the entire network.

A blockchain is often described as an open distributed ledger that can record transactions between two parties efficiently, and in a highly verifiable and permanent manner.
In addition, the ledger can also be programmed to trigger transactions automatically.

The secure decentralised nature of blockchain technology makes it potentially suitable for the recording of events, medical records, records management of cryptocurrencies and their transactions, identity management and documentation of provenance.

The first blockchain was conceptualised in 2008 and implemented the following year as a core componenent of the digital currency Bitcoin, where it serves as a public ledger for all transactions.
The invention of the blockchain for Bitcoin created the first digital currency to solve the “double spending” problem, without the use of a trusted authority or a central server.
A double spend is an attack where a given set of coins is spent in more than one transaction.
There are a number of ways to perform a double spend:

*Send two conflicting transactions in rapid succession into the Bitcoin network.
This is called a race attack.

* Pre-mine one transaction into a block and spend the same coins before releasing the block to invalidate that transaction.
This is called a Finney attack.

* Own 51+% of the total computing power of the Bitcoin network to reverse any transaction you feel like, as well as have total control of which transactions appear in blocks.
This is called a 51% attack.
Long term, it could present a major concern if global companies (particularly banks and pharma companies) decide to use their enormous financial powers to create 51% or more in computing power of blockchain ownership.

To prevent damages from the first attack – wait for one confirmation to appear on a given transaction.
To prevent damage from the second attack – wait for 6 confirmations to appear on a transaction, or less if the transaction is small (but still require at least 1).
Damage from the third attack can cripple the entire Bitcoin network, so don’t worry about it – your business most likely won’t be the main target (it’s unlikely to happen just now unless really big money gets involved).

Governments of Australia, the US, UK and Canada have already become interested in the blockchain technology because of its potential to eliminate Medicare-type fraud.
Government regulation would almost inevitably require a ceiling on the digital currency individual ownership stakes to preserve the integrity of the entire system

The Bitcoin design has now become the model for a range of applications including other digital currencies.
Because of the secure chain of history available in digital currency transactions, the value of the currency is maintained, and is compared to the backing of a national currency with gold.

The thinking around blockchain in healthcare is now moving past the theoretical stages and is even spurring activity from major companies and venture capitalists.

Health IT giant Philips has launched a blockchain-in-healthcare lab and joined a new blockchain-in-healthcare network led by blockchain vendor Gem.
And accounting and consulting firm Deloitte has released several bullish reports on blockchain in healthcare and formed partnerships with several blockchain start-ups.

Because blockchain is a distributed public ledger linked by what supporters say is a nearly impregnable cryptographic chain, it has the potential to solve health IT’s most intractable problems: lack of interoperability and securing the integrity, completeness and privacy of health records.

Blockchain-in-healthcare advocates maintain that the technology has the potential to be as disruptive as the cloud or EHRs — not immediately, but over the next few years.

Short term in the next three years it’s going to be slow traction.
Between 2017 and 2020, there will be inflated expectations and after that a full emergence in the consumer interaction area, where products and software and the underlying technology will be common-place.
Blockchain in healthcare will be transformative – disruptive to traditional heath IT systems and inevitable.

Blockchain’s importance in digital currency creates an alternative form of investment and to insulate individuals against corrupt government actions such as the printing of new banknotes without any formal backing value, so as to totally devalue a nation’s currency.
The US government is considered by a number of analysts as being insolvent and not in a position to service its $’s multi-trillion debts.
So we will see an exit from the US dollar into digital currencies, particularly a new one called Ethereum.

The new digital currency called Ethereum has now evolved and eliminates some of the problems of Bitcoin (slow processing because of rapid acceptance and increased user numbers).
Bitcoin is premised on having a fixed amount of coin in circulation.
Ethereum allows for scalability but is gold-backed.

This will be a game-changer globally, particularly as the US dollar becomes more unstable in international trade.
Digital currencies based on gold will be universally accepted on a global scale, and that will also be the driver for an increase in global trade initiatives without involvement of mainstream banks.
As one commentator remarked:
“For thousands of years citizens have desired the ability to trade, own and gift gold in a manageable way and now we have the technology to enable this. It will surely change how gold is stored and distributed with a new type of custodian relationship being created and enabled by the blockchain.
This will also reintroduce gold-backed currencies into global circulation over time around the world.”

Meanwhile, i2P readers should take note of the blockchain developments which are liable to impact pharmacy activities in the not-too-distant future.
This may be the first time you have read about the potential of blockchain technology.
i2P will be releasing more information progressively as to how pharmacists can benefit from this knowledge and its applications, as it becomes available.

For the moment i2P would advise caution in any IT investment associated with patient records, but would suggest homework be done on how you can transact your pharmacy sales through using Bitcoin and Ethereum digital currencies.
It is inevitable that blockchain technology will be formalised as some form of a government standard because of its ability to virtually eliminate fraud or tampering with information stored in centralised databases.
In health, blockchain holds out the promise of developing patient records covering an entire lifetime, efficiently, economically and accurately through more diverse input from a range of sources not previously able to be accessed – with the value of that information multiplying as all health professions are able to access for patient benefit.
Medical lobbying and interventions to monopolise patient records will reduce, as the ability to manipulate blockchain is found to be virtually impossible.

Footnote:
Interest is building for digital currencies via YouTube and other social media platforms.
The following is a small educational note and video posted on YouTube