QLunch: Christian Majenz

Speaker: Christian Majenz from QuSoft

Title: Quantum copy-protection of compute-and-compare programs in the quantum random oracle mode


Copy-protection allows a software distributor to encode a program in such a way that it can be evaluated on any input, yet it cannot be "pirated" - a notion that is impossible to achieve in a classical setting. Aaronson (CCC 2009) initiated the formal study of quantum copy-protection schemes, hoping that the no-cloning theorem could enable such a functionality, and exhibiting a secure scheme given access a tailored unitary oracle. In this talk, I will present a construction of a copy-protection scheme for (slightly more than) point functions, offering non-trivial provable security relative to a random oracle, i.e. a quantum oracle for a random function (e.g. from n bits to n bits). In cryptography, it is a widely accepted idealization to model cryptgraphic hash functions as random oracles, offering a way to implement our scheme. Following a recent paper by Broadbent and Lord, security is reduced to so-called monogamy of entanglement games.

2009.13865, Joint work with Andrea Coladangelo and Alexander Poremba.