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US 7,587,439 B1Granted
Method and apparatus for generating a random bit stream in true random number generator fashion
AssigneeIntergrated Device Technology, Inc.
InventorsPeter Z. Onufryk, Nelson L. Yue
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Abstract
A method and apparatus for generating a random bit stream in true random number generator fashion are described. Two periodic signals are employed in generating the random bit stream. A first periodic signal having preferably an approximately fifty percent duty cycle and jitter induced by supply and substrate noise is sampled by a second periodic signal that is relatively jitter-free and of a lower frequency than the first periodic signal.
Claims40
A method for generating a random bit stream, comprising:
- generating an oscillating signal subjected to random noise using a plurality of bit source oscillators to provide random bit streams generated using supply and substrate noise on an integrated circuit chip as jitter sources and tapping said oscillating signal from a ring oscillator circuit including single-ended inverting stages that are sensitive to supply and substrate noise;
- generating a first periodic signal having jitter from the oscillating signal by passing said oscillating signal through a frequency divider, thereby restoring its duty cycle to an approximately fifty percent duty cycle;
- generating a second periodic signal that is relatively jitter-free and has a lower frequency than said first periodic signal;
- sampling the first periodic signal with the second periodic signal to generate a random bit stream;
- and
- coupling the random bit stream to a security engine, the security engine operable to perform cryptographic applications using the random bit stream.
3 more elements
An apparatus for generating a random bit stream, comprising:
- a plurality of bit source oscillators providing random bit streams generated using a supply and substrate noise on an integrated circuit chip as a jitter source, wherein each of the plurality of bit source oscillators comprises a ring oscillator circuit including a plurality of inverting stages comprising single-ended inverting stages that are sensitive to said supply and substrate noise, said plurality of inverting stages subjected to said jitter source for generating an oscillating signal having jitter;
- a duty cycle restorer circuit coupled to said ring oscillator circuit for generating a first periodic signal from said oscillating signal so as to exhibit jitter and an approximately fifty percent duty cycle;
- and
- a sampling circuit coupled to said duty cycle restorer circuit for generating a random bit stream by sampling said first periodic signal with a second periodic signal relatively jitter-free with a lower frequency than said first periodic signal.
1 more element
Dependencies are inferred from the claim text.