1. An apparatus for generating physical random numbers, comprising: a physical random number generator configured to generate physical random numbers; a test unit configured to perform a test process to check randomness of the physical random numbers; a minimum entropy estimating unit configured to estimate a minimum entropy based on statistical information generated as a byproduct of the test process; an entropy compressing unit configured to perform an entropy compression process using the physical random numbers as an input; and an entropy control unit configured to control based on the minimum entropy a number of bits of the physical random numbers input into the entropy compression process performed by the entropy compressing unit.