A generator device being configured for generating pseudo random numbers, the generator device comprising a computing device operable for (i) calculating a first hash chain from an initial hash value (H_0), the first hash chain comprising a first sequence of M hash values (HA_1, HA_2, . . . , HA_M); (ii) calculating a second hash chain (20) comprising a second sequence of M hash values (HB_1, HB_2, . . . , HB_M) from the initial hash value (H_0) and the hash values (HA_1, HA_2, . . . , HA_M) of the first sequence; and (iii) determining the pseudo random numbers from the hash values (HB_1, HB_2, . . . , HB_M) of the second sequence. Also disclosed are a method for generating pseudo random numbers and a method for quantum computing secure authentication, as well as a computer program product and a data processing system.