Method and apparatus for generating random numbers

A random number generator comprising:

• an oscillator supplying an oscillator output signal having a frequency determined according to a control input;
• a sampling circuit coupled to the oscillator to sample the oscillator output signal, using a sample clock at a sampling frequency that is asynchronous to and lower than the frequency of the oscillator output signal;
• wherein the control input is coupled to cause the oscillator output frequency to change significantly within each sample period of the sample clock;
• and
• wherein the oscillator is one of a numeric controlled, voltage controlled and current controlled oscillator;
• and
• wherein the sample clock is coupled to generate, at least in part, the control input for the oscillator, the sample clock changing values within each sample period, thereby causing the oscillator output frequency to change significantly within each sample period.

A random number generator comprising:

• an oscillator supplying an oscillator output signal having a frequency determined according to a control input;
• a sampling circuit coupled to the oscillator to sample the oscillator output signal, using a sample clock at a sampling frequency that is asynchronous to and lower than the frequency of the oscillator output signal;
• a linear feedback shift register whose outputs are coupled to generate at least, in part, the control input;
• and
• wherein the control input is coupled to cause the oscillator output frequency to change significantly within each sample period of the sample clock.

A random number generator comprising:

• an oscillator supplying an oscillator output signal having a frequency determined according to a control input;
• a sampling circuit coupled to the oscillator to sample the oscillator output signal, using a sample clock at a sampling frequency that is asynchronous to and lower than the frequency of the oscillator output signal;
• a distilling circuit coupled to receive the output of the sampling circuit and generate an N bit output therefrom;
• and
• wherein the control input is coupled to cause the oscillator output frequency to change significantly within each sample period of the sample clock.

A method of generating a random number comprising:

• supplying an oscillator output signal having a frequency determined according to a control input;
• sampling the oscillator output signal in a sampling circuit using a sampling clock at a sampling frequency lower than and asynchronous to the frequency of the oscillator output signal and supplying a sampled output signal indicative thereof,
• changing the oscillator output frequency significantly during each sampling interval using the control input;
• shifting the sampled output signal into a linear feedback shift register;
• generating pseudo random numbers in the linear feedback shift register;
• and
• generating the control input using the pseudo random numbers.

A method of generating a random number comprising:

• supplying an oscillator output signal having a frequency determined according to a control input;
• sampling the oscillator output signal in a sampling circuit using a sampling clock at a sampling frequency lower than and asynchronous to the frequency of the oscillator output signal and supplying a sampled output signal indicative thereof;
• changing the oscillator output frequency significantly during each sampling interval using the control input;
• and
• shifting successive outputs from the sampling circuit into a distilling circuit to generate an N bit random number.

A random number generator comprising:

• an oscillator supplying an output signal;
• means for sampling the output signal and supplying a sample signal indicative thereof;
• means for changing oscillator output frequency significantly during each sampling period;
• and
• means for distilling successive sample signals.