The Blockchain and The Byzantine Generals Problem


Twenty years ago, nobody would have predicted the impact that a popularized global information network would have on society–and even though the internet has only been around for a little over two decades, we still have yet to max out its potential, with wearables, connected home devices, and other Internet of Things (IoT) components just recently becoming popular. Nevertheless our dependence on the worldwide web is easily demonstrated. For example, in 2014, it was calculated that $1.2 million dollars worth of business was done every 30 seconds online, and Pew Research released a report showing that only about 13 percent of Americans don’t use the internet.

You would think that a resource this valuable and regularly used would be relatively harmless and well-secured. Unfortunately, you’d be wrong. Over 32 percent of the world’s computers are currently infected with malware, and in 2016 alone, half of all businesses were hit by ransomware causing more than $1 billion in damages. To add to all of that, the Dyn DDoS attack that occurred in October 2016, which was the biggest DDoS attack in history at the time, actually took down half of the US’s internet for a day by taking over a million consumer smart cameras and other devices hooked up to the internet.

The reasons for such abysmal security standards are many, but the net result is the same, causing Wired to dub the IoT “wildly insecure”. A solution has yet to be implemented, but rumblings of a new technology poised to sweep the cyber-landscape have arisen: the blockchain, the technology that powers bitcoin, is quite possibly the solution that will patch vulnerabilities across the internet as a whole.

Of Bitcoins and Byzantine Generals

For those unfamiliar with the blockchain, it is a complex distributed ledger that self-maintains a growing list of data “blocks” that cannot be forged or retroactively altered. From Wikipedia: “By design, blockchains are inherently resistant to modification of the data — once recorded, the data in a block cannot be altered retroactively. Through the use of a peer-to-peer network and a distributed timestamping server, a blockchain database is managed autonomously. Blockchains are “an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable and permanent way.”

One of the most important aspects of the blockchain is its ability to record data without fault or fallacy, meaning that data tampering is impossible. Joey Krug of bitcoin and blockchain analysis and prediction firm Augur believes that this problem, also known as the Byzantine General’s problem, is part of why the blockchain holds such massive potential.

“It’s supposed to be impossible to solve in theory,” he says in an interview published by FundersClub, “but Bitcoin solved it in practice, which was an amazing thing.”

The Byzantine General’s problem is the computer-world’s practical take on (and another name for) a thought-experiment called the Two Generals’ Problem. Essentially, the problem is illustrated by two or more generals sieging a city from opposite sides, trying to coordinate an attack. If General A sends a message that says “attack at noon tomorrow,” he has no idea whether or not General B will actually receive the message, and could potentially be marching toward death if he attacks without the other general. Upon receipt, General B has no idea if the message is authentic or has been sent from the enemy to draw him into a trap. Nevertheless, he will assume authenticity and send a response confirming the attack, but without knowing whether General A received his response, he may fear that the other general will hold off attacking, meaning that General B will be the one attacking alone at noon tomorrow and facing certain death. General A could, of course, send a message confirming receipt of General B’s acknowledgement, but will never actually know if it reached its destination, or even if the message was authentic in the first place. This puts him in the same spot General B was just in. This problem bounces back and forth into perpetuity, with neither general ever able to be sure whether their message went through, let alone is authentic.

Applying Knowledge of the Block

The blockchain is unique because it relies on nodes, and all of these nodes talk to each other, simultaneously verifying authenticity of a packet of information and that it was received. If one block is tampered with, all of the other nodes will notice the discrepancy. Without getting too complicated, the blockchain applied to the current DNS infrastructure could both heighten security on the internet, and keep it free and decentralized, without having to worry about government censorship, according to Peter Van Valkenburgh writing for Wired. “No single target, no hack,” he says, in reference to how the previously mentioned Dyn Cyberattack could have been prevented.

Best of all, inside and outside of cybersecurity both, the blockchain has what seems like near-limitless application. Smart contracts mean that you’ll never have to rely on a notary again or wait for a clearinghouse to clear your checks. The internet revolutionized taxation once already with e-filing–but the blockchain promises to automate taxes so we’ll never have to deal with that headache again. Most spectacularly, the blockchain could be used to create tamper-proof elections the likes of which President Trump could never accuse of being rigged, because mathematically they couldn’t be.

It’s a wonder that this technology hasn’t been pursued in fervor considering that it presents mathematical truth in situations that people would prefer to game the most. However, by educating ourselves on potential protections, the average citizen will be better armed to fight for their rights in a dismally unsecured digital landscape.

Andrew Heikkila is a tech enthusiast, a futurist, and a business owner from the Pacific Northwest. He believes in the power of technology to guide the world in the right direction, but also understands human fallibility means it won't always be used to these ends. Still, he has hope that people will transcend their natural devices, and become the beings we have the potential to be. You can follow him through the buttons below.