Gap histogram on-line randomness test

A method for testing a stream of random numbers generated by a random-number generator, the method comprising the steps of:

• (a) segmenting said random binary bits into a predefined block of bits;
• (b) applying said segmented random bits to a gap-length calculation;
• (c) applying the output of said gap-length calculation to an exponential averaging counting to obtain and update a gap-frequency value between at least two identical blocks of bits;
• (d) comparing the gap-frequency value to a predetermined acceptance range;
• and,
• (e) determining whether at least one of the gap-frequency values falls outside said predetermined acceptance range more than a predefined number of times.

A system for testing randomness, comprising:

• a random-number generator for generating a random sequence comprising binary bits;
• a detector for detecting whether said generated random sequence is sufficiently random based on an exponential-gap-frequency operation;
• and,
• a switch for controlling the flow of said generated random sequences for a subsequent application based on the outcome of said exponential-gap-frequency operation,
• wherein said random sequence is segmented into a predefined block of bits to undergo said exponential-gap-frequency operation to obtain and update gap frequency values between at least two identical blocks of bits and wherein, if at least one of the gap-frequency values repeatedly falls outside a predetermined acceptance range more than a predefined number of times, determining that said generated random sequences are insufficiently random.

A machine-readable medium having stored thereon data representing sequences of instructions, and the sequences of instructions which, when executed by a processor, cause the processor to:

• generate a continuous stream of random binary bits;
• segment said random binary bits into a predefined block of bits;
• apply each said predefined block of bits to an exponential-gap-frequency calculation to compute and update gap-frequency values between at least two identical blocks of bits;
• and,
• determine whether said generated random bits are sufficiently random by comparing the output of said exponential-gap-frequency calculation to a predetermined acceptance range.