# US 2024/0201953 A1 · Random number generator real-time entropy evaluation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2024/0201953 A1 - Document ID: US20240201953A1 - Status: Published application - Kind: A1 - Application number: 18/081,965 - Filed: 2022-12-15 - Published: 2024-06-20 - Earliest claimed: 2022-12-15 - Assignees: NXP B.V. - Applicants: NXP B.V. - Inventors: Björn Fay - Web page: https://patentgrep.com/patent/US20240201953A1 ## CPC - G06F 7/588: {Random number generators, i.e. based on natural stochastic processes} - H04L 9/0869: {involving random numbers or seeds} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract An entropy generator comprises an entropy source to generate a random bitstream and an entropy evaluator communicatively coupled to the entropy source to receive the random bitstream. The entropy evaluator includes a first counter to maintain a repetition count of one or more patterns of multiple bits successively included in the random bitstream, and an alert generator communicatively coupled to the first counter to generate an alert in response to the repetition count exceeding a defined threshold. The repetition count may be based on one or more exclusive-or (XOR) operations of a current bit of the random bitstream with one or more previous bits of the random bitstream. ## Claims ### Claim 1 An entropy generator, comprising: an entropy source to generate a random bitstream; and an entropy evaluator communicatively coupled to the entropy source to receive the random bitstream, the entropy evaluator comprising: a first counter to maintain a repetition count of one or more patterns of multiple bits successively included in the random bitstream; and an alert generator communicatively coupled to the first counter to generate an alert in response to the repetition count exceeding a defined threshold. ### Claim 2 (depends on 1) The entropy generator of claim 1, wherein the repetition count is based on one or more exclusive-or (XOR) operations of a current bit of the random bitstream with one or more previous bits of the random bitstream. ### Claim 3 (depends on 2) The entropy generator of claim 2, wherein the first counter is one of a set of multiple counters of the entropy evaluator, and wherein each counter of the set of multiple counters receives an output of a respective XOR operation of the one or more XOR operations. ### Claim 4 (depends on 3) The entropy generator of claim 3, wherein each respective XOR operation includes as a first operand the current bit of the random bitstream and includes as a second operand a previous bit of the one or more previous bits of the random bitstream. ### Claim 5 (depends on 2) The entropy generator of claim 2, wherein the one or more XOR operations include one XOR operation to XOR a current bit bi of the random bitstream with a previous bit bi−4 that precedes the current bit bi by four positions in the random bitstream. ### Claim 6 (depends on 2) The entropy generator of claim 2, wherein to maintain the repetition count includes to reset the repetition count in response to a positive outcome of one XOR operation of the one or more XOR operations. ### Claim 7 (depends on 1) The entropy generator of claim 1, wherein the repetition count is based on one or more derivatives of the random bitstream. ### Claim 8 (depends on 1) The entropy generator of claim 1, wherein the one or more patterns of multiple bits successively included in the random bitstream include any possible pattern of multiple bits having a bit length of x bits, wherein x is greater than 1. ### Claim 9 A method, comprising: receiving a random bitstream from an entropy source; maintaining, with an entropy evaluator, a repetition count of one or more patterns of multiple bits successively included in the random bitstream; and responsive to the repetition count exceeding a defined threshold, generating an alert regarding the entropy source. ### Claim 10 (depends on 9) The method of claim 9, wherein maintaining the repetition count includes maintaining the repetition count based on one or more exclusive-or (XOR) operations of a current bit of the random bitstream with one or more previous bits of the random bitstream. ### Claim 11 (depends on 10) The method of claim 10, wherein maintaining the repetition count includes maintaining the repetition count based on a set of multiple counters that each receives an output of a respective XOR operation of the one or more XOR operations. ### Claim 12 (depends on 10) The method of claim 10, comprising performing one XOR operation to XOR a current bit bi of the random bitstream with a previous bit bi−4 that precedes the current bit bi by four positions in the random bitstream. ### Claim 13 (depends on 10) The method of claim 10, wherein maintaining the repetition count includes resetting the repetition count in response to a positive outcome of one XOR operation of the one or more XOR operations. ### Claim 14 (depends on 9) The method of claim 9, wherein maintaining the repetition count includes maintaining the repetition count based on one or more derivatives of the random bitstream. ### Claim 15 (depends on 9) The method of claim 9, wherein maintaining the repetition count of the one or more patterns of multiple bits successively included in the random bitstream includes maintaining a repetition count of any possible pattern of multiple bits having a bit length of x bits, wherein x is greater than 1. ### Claim 16 An entropy evaluator, comprising: a first counter to maintain a repetition count of multiple-bit bit patterns successively included in a random bitstream; and an alert generator communicatively coupled to the first counter to generate an alert in response to the repetition count exceeding a defined threshold. ### Claim 17 (depends on 16) The entropy evaluator of claim 16, wherein the repetition count is based on one or more exclusive-or (XOR) operations of a current bit of the random bitstream with one or more previous bits of the random bitstream. ### Claim 18 (depends on 17) The entropy evaluator of claim 17, wherein to maintain the repetition count includes to reset the repetition count in response to a positive outcome of one XOR operation of the one or more XOR operations. ### Claim 19 (depends on 16) The entropy evaluator of claim 16, wherein the repetition count is based on one or more derivatives of the random bitstream. ### Claim 20 (depends on 16) The entropy evaluator of claim 16, wherein to maintain a repetition count of the multiple-bit bit patterns includes to maintain a repetition count of any possible pattern of multiple bits having a bit length of r bits, wherein x is greater than 1.