Quantum computers perform calculations based on the probability of an object’s state before it is measured – instead of just 1s or 0s that classical computers do- this means they have the potential to process exponentially more data about specific functions compared to classical computers.
In quantum computing, operations use the quantum state of an object to produce what’s known as a qubit. These states are the undefined properties of an object before they’ve been detected, such as the coin spinning through the air before it lands in your hand. Rather than having a clear position, unmeasured quantum states occur in a mixed ‘superposition.’ The problem is solving an equation in this state; the superposition needs to be maintained, or it causes information decay. This is one of the challenges to quantum computing.
Currently, all blockchain programming works on classical computing techniques. However, there has been rising speculation amongst the community that quantum computing can destabilize the existing blockchain structures and cause forking. Although this is highly doubted because many protocols are termed as ‘quantum-resistant.’
There is another, more serious threat when it comes to the state of crypto: the ability to mine quickly in a sudden quantum speedup could lead to destabilization of prices and, more importantly, control of the chain itself — an unexpected quantum speedup could, if hidden, lead to vast centralization of mining and possible 51% attacks.
It’s conceivable that these avenues of attack and perhaps other more unpredictable ones might emerge, yet post-quantum encryption planning is already in process — and through the mechanism of forks, crypto can be updated to use post-quantum encryption standards and defend against these weaknesses.
