A General Quantum Duality for Representations of Groups with Applications to Quantum Money, Lightning, and Fire

Aaronson, Atia, and Susskind established that swapping quantum states $|\psi\rangle$ and $|\phi\rangle$ is computationally equivalent to distinguishing their superpositions $|\psi\rangle\pm|\phi\rangle$. We extend this to a general duality principle: manipulating quantum states in one basis is equivalent to extracting values in a complementary basis. Formally, for any group, implementing a unitary representation is equivalent to Fourier subspace extraction from its irreducible representations. Building on this duality principle, we present the applications: * Quantum money, representing verifiable but unclonable quantum states, and its stronger variant, quantum lightning, have resisted secure plain-model constructions. While (public-key) quantum money has been constructed securely only from the strong assumption of quantum-secure iO, quantum lightning has lacked such a construction, with past attempts using broken assumptions. We present the first secure quantum lightning construction based on a plausible cryptographic assumption by extending Zhandry's construction from Abelian to non-Abelian group actions, eliminating reliance on a black-box model. Our construction is realizable with symmetric group actions, including those implicit in the McEliece cryptosystem. * We give an alternative quantum lightning construction from one-way homomorphisms, with security holding under certain conditions. This scheme shows equivalence among four security notions: quantum lightning security, worst-case and average-case cloning security, and security against preparing a canonical state. * Quantum fire describes states that are clonable but not telegraphable: they cannot be efficiently encoded classically. These states "spread" like fire, but are viable only in coherent quantum form. The only prior construction required a unitary oracle; we propose the first candidate in the plain model.