# Pauli one-time pad (Quantum one-time pad) This is the quantum equivalent to classical one-time pad. Given a qubit $|\psi\rangle$ , we return $X^aZ^b|\psi\rangle$ where $a,b\in\{0,1\}$ are the Pauli keys. $X$ flips the value and $Z$ flips the phase and together they hide $|\psi\rangle$. ## for n qubits we compute $\otimes_{i=1}^n X^{a_i}Z^{b_i}|\psi\rangle$ and Pauli key size is $2n$. ## Created 2026-02-15 12:51