The major selling point of blockchain and its applications is that cryptographically secured distributed ledgers are virtually “unbreakable” under normal circumstances, given the current state of computational technology. Its validity, however, is heavily dependent on the “state of technology” assumption. Should a paradigmatic shift in computing occur, contemporary blockchain-based systems may become vulnerable to threats not accounted for in their design. But how urgent is the threat of this happening any time soon?
A quantum computer is any device that uses the principles of quantum mechanics to perform calculations. To store and manipulate information, regular computers use binary units called bits, which can represent one of two possible states: 0 or 1. Quantum machines rely on quantum bits (or qubits), which can be both a 0 and 1 at the same time. This phenomenon, called superposition, allows such devices to perform certain tasks much faster than their bit-based counterparts.