RANDOM NUMBER GENERATOR

• US 3,790,768 A
• Filed: 09/28/1972
• Issued: 02/05/1974
• Est. Priority Date: 09/28/1972
• Status: Expired due to Term

• Current Assignee: Bertrand Dorval, Claude Menard, Paul Chevalier
• Original Assignee: Bertrand Dorval, Claude Menard, Paul Chevalier
• Inventors: Chevalier, Paul, Menard, Claude, Dorval, Bertrand
• Primary Examiner(s): Morrison, Malcolm A.
• Assistant Examiner(s): Malzahn, David H.
• Application Number:
  US05/292,861
• Time in Patent Office: 495 Days
• Field of Search: 235/152 331/78
• US Class Current: 708/251
• CPC Class Codes: G06F 2207/581 Generating an LFSR sequence, e.g. an m-sequence; sequence may be generated without LFSR, e.g. using Galois Field arithmetic
• CPC Class Codes: G06F 2207/583 Serial finite field implementation, i.e. serial implementation of finite field arithmetic, generating one new bit or trit per step, e.g. using an LFSR or several independent LFSRs; also includes PRNGs with parallel operation between LFSR and outputs
• CPC Class Codes: G06F 7/584 using finite field arithmetic, e.g. using a linear feedback shift register
• CPC Class Codes: G06F 7/588 Random number generators, i.e. based on natural stochastic processes
• CPC Class Codes: H03K 3/84 Generating pulses having a predetermined statistical distribution of a parameter, e.g. random pulse generators
• CPC Class Codes: H04L 9/0662 with particular pseudorandom sequence generator

Abstract

A method of generating random numbers which comprises sampling, in a random manner, a pseudo-random generator. The random number generator comprises a pseudo-random number generator for generating pseudo-random numbers, a synchronous random pulse generator for generating synchronous random pulses and sampling means for sampling a pseudo-random number, the sampling being done at each instance one of the synchronous random pulses is generated, whereby to generate an output random number.

Claims

1. A random number generator comprising a pseudo-random number generator for generating pseudo-random numbers, a synchronous random pulse generator for generating synchronous random pulses, and sampling means for sampling a pseudo-random number at each instance one of said synchronous random pulses is generated to generate an output random number having a uniform distribution function.

2. A random number generator as claimed in claim 1 wherein said synchronous random pulses are in synchronism with a clock pulse, said random number comprising a plurality of random bits independent from each other and also from the bits in preceeding random numbers.

3. A random number generator as claimed in claim 1 wherein said sampling means is a sampler comprising a plurality of flip-flops, each bit of said pseudo-random number being connected to an input of each said flip-flOps, a clock pulse and said synchronous random pulse fed to a gate connected to a further input of said flip-flops to enable each said flip-flops each time a synchronous random pulse is received to produce said random number at their combined output.

4. A random number generator as claimed in claim 3 wherein said random number comprises a plurality of random bits, the bit i of said random number is given by the Boolean equation RNi ( Tau + 1) SRP . RNi ( Tau ) + SRP . RNi( Tau ) where RNi( Tau ):

bit i of said random number before the clock pulse RNi( Tau +1);

bit i of said random number after the clock pulse SRP;

output of said synchronous random pulse generator before the clock pulse PRNi( Tau );

bit i of the output number of the pseudo-random number generator before the clock pulse.

5. A random number generator as claimed in claim 1 wherein said sampling means is a sampler comprising a plurality of J-K flip-flops having a common clock signal input, a gate connected to the J and K inputs of each said flip-flops, each said gates having been connected to said pseudo-random generator for receiving a pseudo-random number and to said synchronous random pulse generator for receiving a synchronous random pulse to enable each said flip-flops and to produce said random number at their combined output.

6. A random number generator as claimed in claim 5 wherein said random number comprises a plurality of random bits, the bit i of said random number is given by the Boolean equation RNi( Tau + 1) SRP . RNi( Tau ) + SRP . RNi(t) where RNi( Tau ):

bit i of said random number before the clock pulse RNi( Tau +1);

bit i of said random number after the clock pulse SRP;

output of said synchronous random pulse generator before the clock pulse PRNi( Tau );

bit i of the output number of the pseudo-random number generator before the clock pulse.

7. A random number generator as claimed in claim 1 wherein said synchronous random pulses are fed to a gate to stop in a random manner the pseudo random number generator to yield a random phase in the sequence of pseudo random numbers.

8. A random number generator as claimed in claim 1 wherein said synchronous random pulse generator comprises an analog noise generator generating a high frequency signal, a pulse shaper to amplify and place said high frequency signal on a given level, a synchronizer connected to said high frequency signal at said given level and producing output synchronous pulses and a transition detector connected to said synchronous pulses and transmitting pulses in synchronism with the clock pulses to produce said synchronous random pulses.

9. A random number generator as claimed in claim 8 wherein a plurality of said synchronous random pulse generators have their output connected in parallel to a summer circuit, said summer circuit being an OR gate which produces an output pulse each time a pulse is present at the output of any one of said synchronous random pulse generators.

10. A random number generator as claimed in claim 1 wherein said output random number is a bit.

11. A random number generator as claimed in claim 1 wherein said pseudo-random number generator comprises a single toggle flip-flop which changes its state at each clock pulse it receives, the output of this toggle flip-flop being the output of the pseudo-random number generator thus obtaining a one bit pseudo-random number.

12. A method of generating random numbers comprising generating a sequence of pseudo-random numbers synchronously with a clock, generating a sequence of random pulses which occur randomly in time but are synchronized with the said clock, and sampling and storing one of said pseudo-random numbers each time said random pulse occurS to obtain a random number.