Blockchain and Quantum Computing

Blockchain and quantum computing are some of the hottest topics within computer science. Lots of theories and misconceptions about these two groundbreaking technologies have been made, so for the sake of avoiding confusion, let’s recap what these two disruptive inventions are all about. 


In short, Blockchain is a distributed ledger that provides consensus amongst in a large decentralized network of parties who do not need to trust each other. The first blockchain was invented with the launch of Bitcoin, which after almost 10 years still have 100% documented uptime and continues to thrive in over more corners of society. 

Quantum computers

Quantum computers are a new type of computer. Since the computer was invented, the core of a computer consists of transistors which are made out of bits. Bits are binary, and can either be 0 or 1, active or inactive. Transistors are combined to form logic gates and modules that can process more advanced commands. The problem is, to make computers more advanced, we need to fit in transistors on smaller and smaller spaces, and we are approaching a physical barrier where quantum physics make things tricky. Hence, quantum computers are starting to pop up, which uses qubits instead of bits. To understand the difference we encourage you to watch the video below, but the key difference between bits and qubits that allows for a quantum computer to process more transactions than a normal computer by a magnitude, is due to qubits superpositioning between 0 and 1. This allows quantum computers to execute more calculations at the same time by a stretch compared to a non-quantum computer.

How a quantum computer could destroy blockchain and cryptocurrency

The problem with quantum computers and security is that a private key can be derived from your public key via brute force, if the computer is powerful enough. In other words, the first person to have a quantum computer will be able to hack all cryptocurrency wallets by knowing the public keys shown on the blockchain. With a total market cap of almost $400bn, the economic incentive for inventing such a quantum computer is already substantial.


Quantum computers and quantum blockchains

A team of Russian researchers has recently developed a solution to the quantum-era blockchain challenge, using quantum key distribution (QKD). The team has set out to build a quantum-safe blockchain platform that uses QKD to achieve secure authentication.

 Dr. Evgeniy Kiktenko, from the Russian Quantum Center, Moscow, says: “Blockchain is promising for a wide range of applications. But current platforms rely on digital signatures, which are vulnerable to attacks by quantum computers. This also applies to the cryptographic hash functions used in preparing new blocks, meaning those with access to quantum computation would have an unfair advantage in procuring mining rewards, such as Bitcoins. These risks are significant – it is predicted that 10 percent of global GDP will be stored on blockchains or blockchain-related technology by 2025.”

 Another team led by Del Rajan and Matt Visser at the Victoria University of Wellington in New Zealand is building what they call a quantum blockchain with quantum cryptography. The problem with today’s blockchains is that the security of a blockchain is guaranteed by standard cryptographic functions. These are relatively secure because breaking them requires huge computing resources, which are not generally available, but with quantum computers these resources become more and more accessible. Most teams have proposed quantum cryptography, which merely adds a quantum layer to the standard blockchain protocol. Rajan and Visser’s team suggest making the entire blockchain a quantum phenomenon.

 Their solution is making a quantum blockchain immutable because the photons that it contains do not exist at the current time but are still in existence and readable. This means the entire blockchain is visible but cannot be “touched” and the only entry you would be able to try to tamper with is the most recent one. In fact, Rajan and Visser write, “In this spatial entanglement case, if an attacker tries to tamper with any photon, the full blockchain would be invalidated immediately.”


Where are we going from here?

As more devices and widespread internet adoption continues to sweep the planet, the IT security industry will continue to grow. New technologies within IT security continues to pop up from corporations and governments, and blockchain as well as quantum computers are just the latest additions to this continuous arms race. As a platform that seeks to make cryptocurrency easily accessible to the masses, we at Blockbasis are happy to see that despite a looming security disruptor in the form of quantum computers, blockchain and distributed ledgers will not go extinct any time soon. In other words, with or without quantum computers, distributed ledgers and cryptocurrency is here to stay, the question remains – will cryptocurrency reach the masses? This is what we at Blockbasis is working hard to achieve, using a common tool like email to send and receive any cryptocurrency.