1. A method, performed by a random number generation apparatus, for generating a random number having a signal source biasing removed, the method comprising: generating a raw bit string by sampling, at a predetermined cycle, a physical signal input from a signal source; and generating the random number by performing sequential partial sum on the generated raw bit string, wherein the sequential partial sum indicates each partial sum calculated by shifting a selection range of sample values by one bit when a predetermined number of partial sums are selected from among the generated raw bit string.