# US 10,481,873 B2 · Random number generation using heat assisted magnetic recording > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,481,873 B2 - Document ID: US10481873B2 - Status: Granted - Kind: B2 - Application number: 15/884,952 - Filed: 2018-01-31 - Published: 2019-08-01 - Granted: 2019-11-19 - Earliest claimed: 2018-01-31 - Assignees: Seagate Technology LLC - Applicants: Seagate Technology LLC - Inventors: Li Hong Zhang; WenXiang Xie; Xiong Liu - Web page: https://patentgrep.com/patent/US10481873B2 ## CPC - G06F 7/588: {Random number generators, i.e. based on natural stochastic processes} - G11B 7/13: Optical detectors therefor - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) ## Abstract A method includes detecting noise in a laser output of a heat assisted magnetic recording device. The noise is converted into an electrical signal including a numerical value. A least significant digit of the numerical value is selected. The least significant digit is concatenated with another least significant digit from another detecting of another noise in another laser output to form a number. ## Claims ### Claim 1 A method comprising: detecting noise in a laser output of a heat assisted magnetic recording device; converting the noise into an electrical signal including a numerical value; selecting a least significant digit of the numerical value; and concatenating the least significant digit with another least significant digit from another detecting of another noise in another laser output to form a number. ### Claim 2 (depends on 1) The method of claim 1, wherein the least significant digit is a least significant bit. ### Claim 3 (depends on 1) The method of claim 1, wherein the number is a binary number. ### Claim 4 (depends on 1) The method of claim 1, wherein the electrical signal is an AC signal. ### Claim 5 (depends on 1) The method of claim 1, further comprising combining the least significant digit with another digit from a further detecting of a further noise in a further laser output to form the number, wherein the another digit is selected from a different bit order than the least significant digit. ### Claim 6 (depends on 1) The method of claim 1, wherein the concatenating is independent of an order of the detecting and the another detecting. ### Claim 7 (depends on 1) The method of claim 1, wherein detecting the noise in the laser output includes detecting the noise in the laser output with a photodetector. ### Claim 8 A method comprising: detecting a plurality of laser noises in a heat assisted magnetic recording device; converting the plurality laser noises into a plurality of numerical values; selecting a bit in each numerical value of the plurality of numerical values; and concatenating the selected bits to form a plurality of numbers. ### Claim 9 (depends on 8) The method of claim 8, wherein one of the selected bits is a least significant bit. ### Claim 10 (depends on 8) The method of claim 8, wherein the plurality of numbers is a plurality of binary numbers. ### Claim 11 (depends on 8) The method of claim 8, wherein the converting includes converting the plurality of laser noises into a plurality of electrical signals and then into the plurality of numerical values. ### Claim 12 (depends on 8) The method of claim 8, wherein the selected bits include a first selected bit selected from a first numerical value and a second selected bit selected from a second numerical value, and the first selected bit is selected from a different bit order of the first numerical value than the second selected bit selected from the second numerical value. ### Claim 13 (depends on 8) The method of claim 8, further comprising combining the plurality of laser noises with noises from another source. ### Claim 14 (depends on 8) The method of claim 8, wherein detecting the plurality of laser noises includes detecting the laser noises with a photodiode, a phototransistor, a photon multiplier, or a photo-resistor. ### Claim 15 A method comprising: detecting a plurality of laser outputs; converting the plurality laser outputs into a plurality of numerical values; selecting a digit in each numerical value of the plurality of numerical values, wherein one of the selected digits is a least significant bit; and combining the selected digits to form a plurality of numbers. ### Claim 16 (depends on 15) The method of claim 15, wherein the plurality of numbers is a plurality of binary numbers. ### Claim 17 (depends on 15) The method of claim 15, wherein the converting includes converting the plurality of laser outputs into a plurality of electrical signals and then into the plurality of numerical values. ### Claim 18 (depends on 15) The method of claim 15, wherein the selected digits include a first selected bit selected from a first numerical value and a second selected bit selected from a second numerical value, and the first selected bit is selected from a different bit order of the first numerical value than the second selected bit selected from the second numerical value. ### Claim 19 (depends on 15) The method of claim 15, wherein the selected digits are in a sequence that is independent of the detecting.