  We present a scheme for multi-bit quantum random number generation using a
single qubit discrete-time quantum walk in one-dimensional space. Irrespective
of the initial state of the qubit, quantum interference and entanglement of
particle with the position space in the walk dynamics certifies high randomness
in the system. Quantum walk in a position space of dimension $2^l+1$ ensures
string of $(l+ 2)$-bits of random numbers from a single measurement. Bit
commitment with the position space and control over the spread of the
probability distribution in position space enable us with options to extract
multi-bit random numbers. This highlights the {\it power of one qubit} , its
practical importance in generating multi-bit string in single measurement and
the role it can play in quantum communication and cryptographic protocols. This
can be further extended with quantum walks in higher dimensions.
