  Generators of random sequences used in high-end applications such as
cryptography rely on entropy sources for their indeterminism. Physical
processes governed by the laws of quantum mechanics are excellent sources of
entropy available in nature. However, extracting enough entropy from such
systems for generating truly random sequences is challenging while maintaining
the feasibility of the extraction procedure for real-world applications. Here,
we present a compact and an all-electronic van der Waals (vdW)
heterostructure-based device capable of detecting discrete charge fluctuations
for extracting entropy from physical processes and use it for the generation of
independent and identically distributed (IID) true random sequences. We extract
a record high value ($>0.98~bits/bit$) of min-entropy using the proposed
scheme. We demonstrate an entropy generation rate tunable over multiple orders
of magnitude and show the persistence of the underlying physical process for
temperatures ranging from cryogenic to ambient conditions. We verify the random
nature of the generated sequences using tests such as NIST SP 800-90B standard
and other statistical measures and verify the suitability our random sequence
for cryptographic applications using the NIST SP 800-22 standard. The generated
random sequences are then used in implementing various randomized algorithms
without any preconditioning steps.
