  Random numbers are indispensable resources for application in modern science
and technology. Therefore, a dedicate entropy source is essential, particularly
cryptographic tasks and modern applications. In this work, we experimentally
demonstrated a scheme to generate random numbers by multiplexing eight tunnel
diodes onto a single circuit. As a result, the data rate of random number
generation was significantly enhanced to eight folds. In comparison to the
original scheme that employed one diode, this multiplexing scheme produced data
with higher entropy. These data were then post-processed with the
Toeplitz-hashing extractor, yielding final outputs that achieved almost full
entropy and satisfied the U.S. National Institute of Standards and Technology
(NIST) Special Publication 800-90B validation. These data also passed the NIST
Special Publication 800-22 statistical randomness examination and had no sign
of patterns detected from an autocorrelation analysis.
