  Device-independent quantum key distribution (DIQKD) is the art of using
untrusted devices to distribute secret keys in an insecure network. It thus
represents the ultimate form of cryptography, offering not only
information-theoretic security against channel attacks, but also against
attacks exploiting implementation loopholes. In recent years, much progress has
been made towards realising the first DIQKD experiments, but current proposals
are just out of reach of today's loophole-free Bell experiments. Here, we
significantly narrow the gap between the theory and practice of DIQKD with a
simple variant of the original protocol based on the celebrated
Clauser-Horne-Shimony-Holt (CHSH) Bell inequality. By using two randomly chosen
key generating bases instead of one, we show that our protocol significantly
improves over the original DIQKD protocol, enabling positive keys in the high
noise regime for the first time. We also compute the finite-key security of the
protocol for general attacks, showing that approximately 1E8 to 1E10
measurement rounds are needed to achieve positive rates using state-of-the-art
experimental parameters. Our proposed DIQKD protocol thus represents a highly
promising path towards the first realisation of DIQKD in practice.
