Security Encyclopedia


A qubit, or quantum bit, is the fundamental unit of quantum mechanics, or quantum computing, similar to how bits are the basic unit of classical computing. 

Classical computing uses binary strings of zeros (0s) and ones (1s) called bits as its basic unit of output. Quantum computing uses subatomic particles called qubits as its basic unit. Quantum computing pplies two properties of qubits — superposition and entanglement —  as well as resource-intensive stabilization and management of qubits’ state (as they these are delicate) to produce computers said to have exponentially more power than even the largest classical supercomputers. Qubits’ properties of superposition and entanglement are roughly equivalent to, respectively, the ability to coexist simultaneously and to daisy chain. 

Qubits are sometimes written as qbits. Quantum computing is an ongoing research area whose fruits are a decade or more in the future and accessible mainly to developed nation-states and deep-pocketed multinational organizations.


“Quantum computing is a fascinating research area but since qubits — the subatomic particles on which next-gen computing relies — are wildly unstable and delicate, it’s a way’s off.”