Physical Randomness Extractors: Generating Random Numbers with Minimal Assumptions

Understand

How to generate provably true randomness with minimal assumptions? This question is important not only for the efficiency and the security of information processing, but also for understanding how extremely unpredictable events are possible in Nature.

• All current solutions require special structures in the initial source of randomness, or a certain independence relation among two or more sources.
• Both types of assumptions are impossible to test and difficult to guarantee in practice.
• Here we show how this fundamental limit can be circumvented by extractors that base security on the validity of physical laws and extract randomness from untrusted quantum devices.