In less than a year after the Estonian eHealth Foundation announced that it planned to use blockchain technology to secure the public health records of Estonia's 1.3 million citizens, a ground-breaking system was up and running. The system facilitates improved access to vital information for health professionals, while simultaneously guaranteeing patient confidentiality and the integrity of their files. It's a holy grail of healthcare.
Some of the brightest and best minds on the globe have been applying themselves to the issue of making blockchain both practically useful and commercially viable. So how did the Estonian state and a local firm partner up to achieve what others are still only aspiring to?
What is blockchain?
To understand fully the significance of the achievement, it's best to take a step back and look at what blockchain technology is. A blockchain is a "distributed ledger", a single database which is synchronised across multiple machines in a peer-to-peer network.
Every machine in the network has a copy of the complete blockchain, which means a single version of the blockchain cannot be tampered with or changed without it being immediately noticeable and rejected by other machines in the network. Transactions are usually written into the chain as "blocks" of encrypted data, and multiple machines must confirm an entry before it is added to the master chain along with a cryptographic timestamp that cannot be changed.
The most famous blockchain is the one that underpins the online currency Bitcoin. Indeed, the word itself comes from the Bitcoin creator. It's worth looking at Bitcoin as it exemplifies the advantages and disadvantages of blockchain technology.
The key advantages are that there's no central server to verify transactions: when one Bitcoin user transfers the currency to another, the transaction is authenticated using other Bitcoin owners' PCs. Unlike a traditional database, every transaction ever made in Bitcoin is not only irreversible, it's indelibly written into the blockchain and stored on millions of computers worldwide, so there's a verifiable, incorruptable paper trail for preventing fraud.
The main disadvantage is that over time, blockchains grow, which can slow down transaction speeds. It can take 10-15 minutes to confirm a Bitcoin payment, which is longer than you'd want to spend in a supermarket queue.
Blockchain and healthcare
The potential for blockchain is huge and billions of dollars of R&D money is being spent to develop blockchain solutions that facilitate payments, legal contracts and supply chain auditing.
But Estonia is racing ahead. While almost every other blockchain deployment in the world is at proof of concept phase (barring Bitcoin, of course), Estonia has been using blockchain to secure government records even before the latest foray into health.
In fact, the company which provides the blockchain for Estonian eHealth, Guardtime, has been working on commercially viable blockchain products since it was founded 10 years ago – before Bitcoin. Guardtime was founded in Estonia, proof that the IT-friendly nature of its government is yielding innovative dividends.
"The important thing is that users can completely forget that it's based on blockchain," explains Guardtime's program manager, Ivo Lõhmus. "All you need to know is that it's an immutable service that gives a verifiable signature stamp for the time and date a specific transaction took place."
The eHealth records service is actually split into two parts, Lõhmus explains. The first is a traditional database which contains the actual records themselves. This was a pre-existing database, and can be accessed by licenced healthcare professionals, such as doctors and pharmacists, as well as citizens themselves.
Access to this database is controlled by the national eID card.
Every time a record is accessed or altered, however, the activity is logged in the blockchain, and a "keyless signature" is returned and stored next to the record. These signatures serve as an electronic timestamp which proves when changes were made, while the blockchain independently verifies who made them.
"We are securing the audit log of all actions in the system," Lõhmus explains, "So if there's malicious intent or an employee doing something they shouldn't do, we can't prevent that, but we will record it."
Because the full medical records aren't written into the blockchain, Lõhmus continues, its size won't become unmanageable. A trillion signatures per second can be processed on the current architecture, guaranteeing that however busy the system is, it won't fall over.
Thanks to its robust authentication process, the eHealth system is used by doctors to issue prescriptions between institutions, because they can rest safe knowing that what they enter cannot be tampered with before it reaches the pharmacist. The real genius, however, is the fact that the system is fully transparent.
Any patient can log in and see exactly who has been viewing their records – and can even restrict access to groups of users – any criminal or improper use of files is immediately apparent. Medical staff looking at records with malicious or even mere curious intent will find themselves having to explain their actions.
"The blockchain serves two objectives," says Lõhmus. "One is the provable integrity that a file has not been altered, and the other is insider threat mitigation."
Not only can the blockchain record be used in court to prove illegal access or altering of files has taken place, it's also a way to protect doctors who face spurious malpractice claims.
"Government officials are people too," adds Lõhmus. "They want the transparency and auditabilty it provides. We don't need to take their word for it that patient records are being used correctly, we have the proof - completely rolled out and in production for every record."