High-Frequency Entropy Extraction From Timing Jitter

Abstract

A method for creating entropy in a virtualized computing environment includes waking one or more samplers, each sampler having a sampling frequency; sampling a sample source with each of the one or more samplers; placing each of the samplers in an inactive state when not sampling; determining a difference between an expected value and a sampled value at each sampler; and providing a function of the difference from each of the one or more samplers to an aggregator.

1 . A method for creating entropy in a virtualized computing environment, the method comprising:
 waking one or more samplers, each sampler having a sampling frequency;   sampling a sample source with each of the one or more samplers;   placing each of the samplers in an inactive state when not sampling;   determining a difference between an expected value and a sampled value at each sampler; and   providing a function of the difference from each of the one or more samplers to an aggregator.   
     
     
         2 . The method of  claim 1 , wherein the sample source is an accumulator. 
     
     
         3 . The method of  claim 2 , wherein the sample source is a timer. 
     
     
         4 . The method of  claim 1 , wherein the aggregator controls waking each of the samplers. 
     
     
         5 . The method of  claim 4 , wherein each sampler takes only a single sample per timeslice. 
     
     
         6 . The method of  claim 1 , wherein each sampler is woken at a different interval. 
     
     
         7 . The method of  claim 1 , further comprising:
 determining a timeslice length; and   setting the sampling frequency of each sampler such that the sampler samples no more than once per timeslice.   
     
     
         8 . The method of  claim 1 , further comprising:
 aggregating the differences in the aggregator; and   providing an entropy output from the aggregator for post-processing.   
     
     
         9 . The method of  claim 1 , wherein timeslices are separated by an administrative interval having a varying length. 
     
     
         10 . A system for providing an entropy seed, the system comprising:
 a sample source that provides a value;   two or more samplers coupled to the sample source that sample the value at different times; and   an aggregator that causes the samplers to go into a sleep mode when not sampling and that receives a difference between the value sampled by each sampler and an expected value.   
     
     
         11 . The system of  claim 10 , wherein the sample source is an accumulator. 
     
     
         12 . The system of  claim 11 , wherein the sample source is a timer. 
     
     
         13 . The system of  claim 10 , wherein each sampler takes only a single sample per timeslice. 
     
     
         14 . The system of  claim 10 , wherein each sampler is woken at a different interval. 
     
     
         15 . The system of  claim 10 , wherein the aggregator aggregates the differences in the aggregator and provides an entropy output for post-processing.