Numerical framework for semi-device-independent quantum random-number generators

Quantum random-number generation (QRNG) is one of the most widely applied branches in quantum cryptography. Among all QRNG schemes, semi-device-independent (semi-DI) QRNG is quite promising, achieving high randomness generation rates with few assumptions on the devices. For the central task of a QRNG study-security analysis-numerical approaches become popular for its generality to various semi-DI QRNG schemes. Here we formulate a numerical framework for the finite-size security of general semi-DI QRNGs, which gives a secure lower bound of the finite-size randomness generation rate against general attacks. We consider a simple example of an optical semi-DI QRNG as an application of our framework.