  We produce two strings of quantum random numbers simultaneously from the
intensity fluctuations of the twin beams generated by a nondegenerate optical
parametric oscillator. Two strings of quantum random numbers with bit rates up
to 60 Mb/s are extracted simultaneously with a suitable post-processing
algorithm. By post-selecting the identical data from two raw sequences and
using a suitable hash function, we also extract two strings of identical
quantum random numbers. The obtained random numbers pass all NIST randomness
tests. The presented scheme shows the feasibility of generating quantum random
numbers from the intensity of a macroscopic optical field.
