Semi-device-independent randomness certification using Mermin’s proof of Kochen–Specker contextuality

Randomness is a potential resource for cryptography, simulations and algorithms. Non-local correlations violating Bell's inequality certify the generation of bit strings whose randomness guaranteed in device-independent manner. We provide interesting semi-device independent certification protocols by Kochen-Specker (KS) contextuality. For this, we first cast Mermin's magic-square proof KS contextuality two-qubit system as communication game prepare-measure scenario. This provides two-bit randomness. Further, using magic-star theorem involving three-qubit system, three-bit conjecture that our proposals can be extended to any arbitrary through suitable valid higher dimensional system.