The development of quantum computers poses a threat to current implementations of asymmetric encryption technology, which is used to protect the digital infrastructure of the Internet. This technology is also the basis of most cryptocurrency security protocols, and a working quantum computer could potentially crack even the strongest of those encryption methods. As a result, the cryptocurrency community must begin to prepare now to develop suitable countermeasures against the potential threat of quantum computing technology.
Quantum computers are immensely powerful machines, and they can solve extremely difficult equations in mere minutes that would take even the most powerful of regular computers thousands of years to compute. This is due to the peculiar behavior of qubits, the basic unit of information in a quantum computer. A classical bit can only have a state of either 0 or 1, but a qubit can have a state of both 0 and 1 at the same time. This allows quantum computers to perform computations much faster than even the most powerful of regular computers.
The security of asymmetric encryption (also known as public-key cryptography) relies on creating a key pair – a public key to encrypt and a private key to decrypt. Currently, most modern encryption algorithms use a mathematical trapdoor function – a function that is easy to calculate in one direction (the public key from the private key) but difficult in the other (the private key from the public key). Thus, it is incredibly difficult to calculate the private key from the public key.
However, this security protocol would be rendered obsolete if a quantum computer were to be built. Such a machine could, in theory, quickly and easily crack even the strongest of asymmetric encryption algorithms by simply taking all the possible states at once instead of having to guess them one by one. This would make all the digital infrastructure of the world vulnerable to attack.
The cryptocurrency community must begin to research and develop countermeasures against the threat of quantum computing technology, such as robust quantum-resistant cryptography algorithms. Symmetric key cryptography could re-emerge as a viable security protocol since it would not be vulnerable to quantum attacks. Additionally, quantum cryptography could provide a solution to securely sharing a common key across an open channel.
When it comes to Bitcoin mining, a single miner carrying a quantum computer could gain an edge over all other miners and potentially put the network at risk of a 51% attack. However, the current blockchain consensus protocol limits the effectiveness of such an attack. Additionally, if multiple miners have access to a quantum computer, the risk of such an attack is significantly reduced.
Thus, it is clear that the cryptocurrency community must act now to develop suitable countermeasures against quantum computing technology. Research is being conducted into potential quantum-resistant cryptography algorithms, as well as advances in quantum cryptography, that could make information security possible in a future world rife with quantum computers. With the right preparation, the cryptocurrency ecosystem can hopefully remain secure against the threat of quantum computing technology.
