System for secure key generation using chaotic oscillator-based entropy units

Abstract

A system for secure cryptographic key generation using chaotic oscillator-based entropy units, wherein the system comprises the following: a housing designed for integration into a machine or electronic device; one or more chaotic oscillator units physically arranged within the housing, each chaotic oscillator unit comprising a nonlinear electronic circuit configured to operate in a chaotic dynamic regime to generate an aperiodic analog signal sensitive to initial conditions and intrinsic circuit noise; a signal acquisition unit electrically connected to one or more chaotic oscillator units and configured to receive the aperiodic analog signal, wherein the signal acquisition unit includes an analog conditioning circuit configured to normalize the signal amplitude and limit the signal bandwidth to a predefined operating range; a converter unit that is electrically coupled to the signal acquisition unit and is configured to sample the processed analog signal at time-varying sampling intervals to generate a digital entropy data stream; a processing unit comprising one or more processors operationally linked to a non-volatile memory, wherein the processing unit is configured to perform entropy conditioning operations on the digital entropy data stream to suppress distortions and reduce temporal correlation; a key generation unit that is operationally coupled with the processing unit and configured to convert conditional entropy data into cryptographic key material of a predefined key length; and a secure storage unit that is operationally connected to the key generation unit and is configured to store the cryptographic key material while preventing unauthorized external access, wherein the system is configured to generate cryptographic keys from physically chaotic behavior without relying on deterministic, purely software-based entropy sources.

Description

Technical field of the invention

[0001] The present invention relates to the field of cryptographic systems and secure computer architectures. In particular, it relates to a hardware-based system and an associated device structure for generating cryptographic keys using physical entropy derived from the behavior of chaotic oscillators. These keys are suitable for use in secure processors, communication devices, embedded systems, and machine-level security architectures. Background of the invention

[0002] The secure generation of cryptographic keys forms the basis of modern information security systems, including secure communication, authentication, digital signatures, and data protection mechanisms. Conventional cryptographic key generation methods typically rely on technically sophisticated pseudorandom number generators implemented in software or firmware. Although such generators can produce statistically acceptable randomness under controlled conditions, they remain deterministic at their core and are therefore vulnerable to prediction, state compromise, and replay attacks if internal states or seed values ​​are exposed.

[0003] To address such vulnerabilities, hardware-based entropy sources have been introduced, exploiting physical phenomena such as thermal noise, jitter in electronic circuits, or metastability in logic elements. However, existing hardware entropy sources often exhibit limited entropy density, susceptibility to environmental influences, aging effects, and process variations, and require complex post-processing to meet cryptographic standards. Furthermore, many hardware random number generators rely on narrowly defined noise sources that can be affected by power supply manipulation, electromagnetic interference, or temperature regulation, thus weakening security guarantees.

[0004] Chaotic dynamic systems exhibit inherent sensitivity to initial conditions, broadband spectral characteristics, and non-periodic behavior even under deterministic fundamental equations. Electronic chaotic oscillators, if appropriately designed, can generate complex, unpredictable waveforms that are extremely sensitive to microscopic variations and circuit noise. Despite these advantages, existing implementations of chaotic entropy generation often lack architectural integration with safe key generation logic, fail to consider stabilization or entropy conditioning, or are impractical for use in compact, machine-level safety devices.

[0005] Therefore, there is a need for a secure key generation system and a corresponding physical device that systematically uses the dynamics of chaotic oscillators as the primary entropy source and simultaneously integrates signal conditioning, entropy validation, cryptographic post-processing and tamper-proof operation in a unified, machine-integrable structure.

[0006] The secure generation of cryptographic keys is a fundamental requirement for modern computer systems, communication infrastructures, industrial control environments, and embedded systems that rely on encryption, authentication, and data integrity mechanisms. The strength of any cryptographic method depends directly on the unpredictability and secrecy of the cryptographic keys used. Traditionally, cryptographic key generation has been primarily achieved through software-based methods for generating pseudorandom numbers on general-purpose processors. These approaches are based on deterministic techniques whose initial values ​​are derived from system parameters such as timestamps, process identifiers, memory states, or user interactions. Although these methods are computationally efficient and easy to implement, they are inherently predictable once the internal state or initial value is compromised.Therefore, they are not suitable for environments with high security requirements.

[0007] Existing hardware implementations based on chaos oscillators often exhibit deficiencies in the integration of secure key generation methods. In many cases, chaotic signals are sampled directly without adequate conditioning, leading to distorted bitstreams and residual correlations. Furthermore, these systems often neglect continuous monitoring of entropy quality, making them susceptible to degradation from component aging, environmental influences, or deliberate manipulation. Without adaptive control mechanisms, chaotic oscillators can drift out of their optimal operating ranges, thus jeopardizing long-term stability.

[0008] Another significant drawback of existing solutions is their vulnerability to side-channel attacks. Power analysis, electromagnetic leakage, and fault injection can be exploited to deduce internal states or manipulate entropy sources. Many hardware random number generators expose raw entropy signals to shared processing elements, thus increasing the attack surface. Furthermore, inadequate shielding and a lack of tamper detection allow attackers to manipulate entropy generation through external influences. These weaknesses are particularly problematic in machine-level applications, such as industrial controls, vehicle systems, and secure communication devices operating in harsh environments.

[0009] Scalability and standardization also pose challenges for existing key generation solutions. Systems designed for one class of equipment may not be suitable for others due to differing power budgets, performance requirements, and environmental conditions. Many solutions require complex calibration during manufacturing, increasing costs and reducing yield. Others are based on proprietary designs that are difficult to certify or validate against regulatory standards, hindering their use in regulated industries.

[0010] Existing cryptographic key generation solutions exhibit a combination of determinism, environmental sensitivity, insufficient entropy density, lack of long-term stability, and inadequate resistance to physical and side-channel attacks. Software-based approaches do not offer true unpredictability, conventional hardware entropy sources are susceptible to manipulation and degradation, and many chaos-based systems are not yet sufficiently designed for secure, machine-integrated deployment. These limitations highlight the need for a robust system that systematically leverages chaotic physical dynamics within a controlled hardware architecture, integrates continuous entropy evaluation, and provides secure key generation and protection mechanisms for modern, highly secure computing and machine environments. Summary of the invention

[0011] The present invention describes a system and an associated device for secure cryptographic key generation using one or more chaotic oscillator-based entropy units. The system uses electronically implemented chaotic oscillators configured to operate in defined nonlinear regions and generate high-entropy analog signals. These signals are captured, digitized, processed, and analyzed to generate cryptographically secure key material suitable for symmetric and asymmetric cryptographic applications.

[0012] The described system integrates entropy extraction, temporal decorrelation, bias suppression, entropy quality assessment, and key derivation in a coordinated hardware architecture. The device's design offers a compact, machine-implementable structure with oscillator circuits, signal acquisition units, processing circuits, secure memory elements, and external interfaces, thus enabling its use in secure processors, embedded controllers, industrial machinery, and communication devices.

[0013] The main objective of the present invention is to provide a secure and reliable system for cryptographic key generation that derives entropy from the physical chaotic behavior of oscillators rather than from deterministic software processes. This ensures a high degree of unpredictability and resistance to key prediction attacks. The invention aims to create a hardware-based entropy source that remains robust even under partial system compromise, environmental fluctuations, or repeated operating cycles.

[0014] A further objective of the invention is to provide a cryptographic key generation system that integrates one or more chaotic oscillator-based entropy units with circuits for controlled signal acquisition, conditioning, and processing. This transforms raw chaotic signals into statistically undistorted and temporally decorrelated entropy suitable for cryptographic applications. The invention aims to perform the entropy extraction in such a way as to minimize correlations, suppress distortions, and preserve the intrinsic randomness generated by nonlinear chaotic dynamics.

[0015] A further objective of the invention is the continuous monitoring and validation of entropy quality during system operation. This allows the key generation process to dynamically adapt to changing operating conditions, component aging, or external disturbances. The invention aims to prevent unnoticed deterioration of the entropy sources and ensure compliance with cryptographic security requirements throughout the system's entire operating life.

[0016] A further objective of the invention is to provide a secure key generation function that converts conditional entropy into cryptographic keys of defined length and format, while preventing the direct disclosure of raw entropy or internal states. The invention aims to ensure that the generated keys are suitable for use in symmetric encryption, asymmetric key generation, authentication protocols, and secure communication systems without the need for external randomness sources.

[0017] A further objective of the invention is to provide a machine-integrable device structure that physically encloses chaotic oscillator circuits, processing circuits, and secure storage elements in a tamper-proof housing. This is intended to protect the key generation process from physical inspection, fault injection, and environmental influences, thereby increasing its resilience against side-channel and hardware-based attacks.

[0018] A further objective of the invention is to achieve scalability and adaptability in a wide range of machine and computing environments, including embedded systems, industrial controls, communication devices, and secure processors. The invention is intended to function under various performance, energy, and environmental conditions without complex calibration or manual intervention.

[0019] A further objective of the invention is to reduce dependence on complex software-based mechanisms for random number generation and external entropy provision. This simplifies system design while simultaneously improving overall security. The invention aims to provide a self-contained, hardware-centric solution that can serve as a trusted entropy and key generation base within broader security architectures.

[0020] A further objective of the invention is to ensure long-term reliability and reproducibility of secure key generation by maintaining stable chaotic operation through controlled circuit design and adaptive parameter management. The invention aims to minimize the effects of manufacturing tolerances, thermal drift, and aging on entropy generation without compromising unpredictability.

[0021] A further objective of the invention is to facilitate compliance with cryptographic and security-related evaluation standards by providing a deterministic hardware architecture whose entropy generation, processing, and monitoring can be formally analyzed, tested, and validated. This is intended to enable its use in regulated environments with high security requirements where certification and auditability are necessary.

[0022] Another objective of the invention is to improve the overall security of the system by closely linking physical entropy generation with secure storage and controlled key release mechanisms, thereby ensuring that the cryptographic keys generated by the system cannot be reconstructed, duplicated or derived by unauthorized actors even under advanced attack models. BRIEF DESCRIPTION OF THE IMAGE

[0023] These and other features, aspects and advantages of the present invention will be better understood if the following detailed description is read with reference to the accompanying drawing, in which the same symbols represent the same parts: Fig. Figure 1 shows a block diagram of a system for secure cryptographic key generation using entropy units based on chaotic oscillators.

[0024] Furthermore, those skilled in the art will recognize that the elements in the drawing are simplified and not necessarily drawn to scale. For example, the flowcharts illustrate the process by highlighting the main steps to facilitate understanding of the present disclosure. With regard to the construction of the device, one or more components may be represented in the drawing by conventional symbols. The drawing may show only the specific details relevant to understanding the embodiments of the present disclosure, so as not to clutter the drawing with details that are already apparent to those skilled in the art from the description contained herein. Detailed description of the invention

[0025] To facilitate understanding of the principles of the invention, reference is made below to the embodiment shown in the drawing, which is described using specific terms. It is understood, however, that this does not limit the scope of protection of the invention. Rather, modifications and further developments of the depicted system, as well as further applications of the inventive principles shown therein, are conceivable, insofar as they would normally occur to a person skilled in the art in the field of the invention.

[0026] It will be clear to those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not to be understood as a limitation of it.

[0027] References to “an aspect”, “another aspect”, or similar phrases in this description mean that a particular feature, structure, or property described in connection with the embodiment is included in at least one embodiment of the present disclosure. Therefore, phrases such as “in one embodiment”, “in another embodiment”, and similar expressions in this description may, but do not necessarily, all refer to the same embodiment.

[0028] The terms "includes," "comprehensive," or similar expressions denote non-exclusive inclusion. Thus, a procedure or method containing a list of steps does not only include those steps but may also include further steps not explicitly listed or inherent in the procedure or method. Likewise, the statement "includes..." for one or more devices, subsystems, elements, structures, or components, without further limitations, does not preclude the existence of other devices, subsystems, elements, structures, or components.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meanings generally known to those skilled in the art in the field to which this invention belongs. The systems, methods, and examples described herein serve only for illustration and are not to be understood as limiting.

[0030] Embodiments of the present disclosure are described in detail below with reference to the attached drawing.

[0031] Fig.Figure 1 shows a block diagram of a system for secure cryptographic key generation using chaotic oscillators. The system 100 comprises: a housing (102) for integration into a machine or electronic device; one or more chaotic oscillators (104) in the housing, each oscillator containing a nonlinear electronic circuit operating in a chaotic dynamic range and generating an aperiodic analog signal that responds to initial conditions and intrinsic circuit noise; a signal acquisition unit (106) electrically connected to the oscillator(s) and receiving the aperiodic analog signal. The signal acquisition unit includes an analog signal conditioning circuit for normalizing the signal amplitude and limiting the signal bandwidth to a predefined range;A conversion unit (108) electrically connected to the signal acquisition unit, which samples the conditioned analog signal at time-varying sampling intervals to generate a digital entropy data stream. A processing unit (110) with one or more processors connected to non-volatile memory, the processing unit being configured to perform entropy conditioning operations on the digital entropy data stream to suppress distortion and reduce temporal correlation; a key generation unit (112) connected to the processing unit and configured to convert conditioned entropy data into cryptographic key material of a predefined key length;and a secure storage unit (114) connected to the key generation unit and configured to store the cryptographic key material while preventing unauthorized external access, the system being configured to generate cryptographic keys from physically chaotic behavior without relying on deterministic, purely software-based entropy sources.

[0032] In one embodiment, each chaotic oscillator unit (104) comprises a feedback network of nonlinear electronic components arranged to amplify microscopic variations caused by thermal noise, component mismatch, and electrical disturbances, such that the resulting analog signal exhibits broadband spectral characteristics and a non-periodic temporal evolution over extended operating periods.

[0033] In one embodiment, the signal acquisition unit (106) further comprises an isolation circuit configured to electrically decouple the chaotic oscillator units from external signal paths and thereby prevent deterministic excitation, electromagnetic injection or modulation of the power supply from influencing the chaotic operating state.

[0034] In one embodiment, the conversion unit (108) is configured to vary the sampling time based on an internally generated time reference derived from a secondary, entropy-dependent process, so that the digital entropy data stream is resistant to reconstruction by fixed-interval analysis.

[0035] In one embodiment, the processing unit (110) is further configured to perform a continuous evaluation of the entropy quality by calculating statistical measures related to the bit distribution, transition density and temporal dependence, and to prevent key derivation when the evaluated entropy quality deviates from predefined acceptance thresholds stored in non-volatile memory.

[0036] In one embodiment, the processing unit (110) is configured to initiate corrective measures upon detection of reduced entropy quality, which include adjusting the oscillator bias conditions, changing the sampling intervals, or temporarily interrupting the key generation output until acceptable entropy characteristics are restored.

[0037] In one embodiment, the entropy conditioning operations performed by the processing unit comprise a multi-stage transformation of the digital entropy data stream by means of non-linear mixing, temporal reordering and state diversification derived from internal memory values ​​that cannot be accessed outside the enclosure.

[0038] In one embodiment, the key generation unit (112) is configured to generate cryptographic keys for at least one of the following operations: symmetric encryption, asymmetric key generation, or creation of authentication tokens. The key generation unit prevents conditional entropy data from being directly transmitted to external interfaces.

[0039] In one embodiment, the secure storage unit (114) comprises a protected storage circuit configured to restrict read access based on internal authorization conditions enforced by the processing unit and further configured to automatically erase stored cryptographic key material upon detection of a tampering state.

[0040] In an embodiment further comprising a tamper detection unit arranged in the housing, configured to monitor at least voltage deviations, temperature fluctuations or indicators of physical intrusion, wherein the tamper detection unit is operationally linked to the secure storage unit to initiate a key zeroing when an abnormal condition is detected.

[0041] The enclosure, chaotic oscillators, signal acquisition unit, conversion unit, processing unit, key generation unit, and secure storage unit are each implemented as physical hardware components and together form an integrated cryptographic device. The enclosure is a rigid housing made of electrically insulating or conductive material that mechanically supports and shields the internal electronic components. Each chaotic oscillator is implemented as a discrete nonlinear electronic circuit consisting of passive and active components electrically interconnected on a circuit substrate to generate chaotic analog behavior due to the inherent circuit dynamics and noise.The signal acquisition unit comprises analog hardware elements such as amplifiers, filters, and voltage regulators, which are connected to the chaotic oscillators via traces to condition the generated signals. The conversion unit is implemented as a hardware-based sampling circuit with clocked comparators and data acquisition registers that convert the conditioned analog signals into digital representations. The processing unit comprises one or more processing components and semiconductor memory elements mounted on a printed circuit board and interconnected via data and control buses to perform entropy conditioning operations. The key generation unit is implemented as a dedicated cryptographic processing circuit or as processor-addressable hardware logic configured to convert conditional entropy into fixed-length key material.The secure storage unit includes physically isolated storage hardware with access control circuits and tamper protection features to prevent unauthorized access to stored cryptographic keys.

[0042] During operation, one or more chaotic oscillators housed within the enclosure are driven into a predefined nonlinear operating range by controlled biasing. Each chaotic oscillator is implemented as a nonlinear electronic feedback circuit in which small disturbances caused by thermal noise, component deviations, and intrinsic electrical fluctuations are continuously amplified by the nonlinear feedback dynamics. Due to the sensitivity of chaotic systems to initial conditions, the internal state of each oscillator does not evolve periodically or repetitively. This generates an analog signal whose instantaneous amplitude and phase cannot be deterministically predicted, even with a known circuit topology.The chaotic oscillators are electrically isolated from external signal paths to avoid deterministic influences and to ensure that the observed behavior is based on internal physical dynamics and not on externally injected signals.

[0043] The analog output signal generated by each chaotic oscillator is routed to the signal acquisition unit, which performs initial signal conditioning before digitization. The signal acquisition unit applies amplitude normalization to prevent saturation and limits the signal to a defined frequency range suitable for sampling through band limiting. This conditioning stage ensures that the full dynamic range of the chaotic signal is utilized while simultaneously suppressing out-of-band noise that does not contribute to usable entropy. Furthermore, an isolation circuit within the signal acquisition unit ensures that loading effects and coupling from downstream circuitry do not affect the chaotic operating state of the oscillators.

[0044] The processed analog signals are passed to the conversion unit, which performs time sampling and analog-to-digital conversion. The conversion unit does not use fixed-period sampling. Instead, the sampling times are varied according to an internally derived time reference that is not phase-locked to the chaotic oscillators. This prevents an attacker from reconstructing the chaotic waveform through repeated observation or synchronized sampling. Each sampling operation captures a snapshot of the chaotic signal state and converts it into a digital representation that is part of a raw data stream of digital entropy.

[0045] The raw digital entropy data stream is then fed to the processing unit, which comprises one or more processors and non-volatile memory for storing operating parameters and acceptance criteria. The processors execute entropy conditioning logic that transforms the raw sampled data into a form suitable for the cryptographic application. This conditioning process involves the nonlinear mixing of successive samples, the temporal reordering of data segments, and internal state diversification using values ​​held in memory that are inaccessible to external interfaces. These operations collectively suppress distortion, reduce the correlation between adjacent samples, and prevent the underlying chaotic waveform from being directly derived from the conditioned output signal.

[0046] In parallel with entropy preparation, the processing unit performs a continuous evaluation of entropy quality. Statistical characteristics of the processed data stream, including distribution equilibrium and transition behavior, are assessed against predefined thresholds stored in non-transitory memory. If the evaluated characteristics deviate from acceptable entropy quality, the processing unit interrupts further key derivation and initiates corrective actions. These may include adjusting the bias conditions of the chaotic oscillators, modifying the sampling behavior of the conversion unit, or temporarily suspending entropy extraction until acceptable behavior is restored. This adaptive feedback mechanism ensures that entropy degradation caused by environmental influences, component aging, or disturbances does not lead to weak key material.

[0047] Once the conditional entropy data stream meets the acceptance criteria, the processing unit forwards the entropy data to the key generation unit. This unit transforms the entropy data into cryptographic key material of predefined length and structure. This transformation is performed in such a way that the conditional entropy is not directly accessible outside the secure area of ​​the system. Depending on the system configuration, the derived cryptographic keys can either be used immediately or stored for subsequent cryptographic operations.

[0048] The generated cryptographic key material is stored in the secure storage unit. This unit contains protected memory circuitry that restricts read and write access based on authorization conditions enforced internally by the processing unit. The secure storage unit is designed to prevent physical intrusion and unauthorized access, thus ensuring that cryptographic keys cannot be extracted in plaintext. Access to the stored keys is via controlled interfaces that allow the use of the keys for cryptographic operations without revealing the underlying key values.

[0049] The system also features a tamper detection unit that monitors physical and electrical parameters within the enclosure, including voltage levels, temperature conditions, and signs of physical interference. Once the tamper detection unit detects an abnormal condition indicating a potential attack, it prompts the secure storage unit to immediately erase the stored cryptographic key material and signals the processing unit to halt entropy extraction and key generation. This response prevents key compromise even in the event of physical access to the device.

[0050] In configurations with multiple chaotic oscillators operating simultaneously, the processing unit combines the entropy data streams generated by each oscillator. Due to deliberately chosen parameter deviations between the oscillators, the evolution of the chaotic state of each individual oscillator remains statistically independent. The nesting or combination of these independent entropy sources increases the entropy density and ensures that the impairment or failure of a single oscillator does not compromise the overall safety of the system.

[0051] Throughout operation, the integrated electromagnetic shielding reduces unintentional signal leakage and susceptibility to side-channel monitoring. The system is capable of generating cryptographic keys at system startup, during normal operation, and in power-saving states, thus providing a continuous, hardware-based entropy source independent of operating system services or external random inputs. In this way, the described system implements a robust, adaptive, and physically sound method for secure cryptographic key generation that meets system requirements and is suitable for use in safety-critical environments.

[0052] The system for secure key generation using chaotic oscillator-based entropy units comprises a physical entropy generation subsystem, a signal acquisition and conditioning subsystem, a digital processing subsystem, and a secure output and storage subsystem, all of which are operationally interconnected within a controlled hardware environment.

[0053] The physical entropy generation subsystem comprises one or more chaotic oscillator units implemented using nonlinear electronic components and exhibiting chaotic dynamics. Each chaotic oscillator unit is configured to operate within a parameter range that generates aperiodic broadband oscillations characterized by high sensitivity to initial conditions and circuit-level noise. The oscillator units can be implemented using analog nonlinear feedback networks, mixed-signal circuits, or digitally augmented analog oscillators and are isolated from external control signals to prevent deterministic influences.

[0054] The chaotic oscillators generate continuous analog signals whose state evolution follows nonlinear paths. These signals inherently contain microscopic thermal noise, component deviations, and quantum fluctuations, which are amplified by the chaotic dynamics, resulting in output signals with high entropy. To further increase unpredictability, the system allows for the parallel operation of multiple chaotic oscillators, with minor parameter deviations arising from manufacturing tolerances or controlled bias offsets.

[0055] The signal acquisition and processing system is electrically coupled to the chaotic oscillator units and includes an analog input circuit for capturing the oscillator outputs. This system performs amplitude normalization, bandwidth shaping, and time sampling of the chaotic signals. An analog-to-digital conversion structure samples the processed signals at non-harmonically correlated sampling intervals to reduce correlations and avoid synchronization artifacts.

[0056] The digitized samples are forwarded to the digital processing system, which comprises one or more processors with non-volatile memory. The processors are configured to perform entropy treatments that remove statistical distortions and temporal dependencies from the sampled data. These treatments include decorrelation through temporal mixing, nonlinear transformations, and entropy whitening processes, implemented in hardware logic or processor-executed routines.

[0057] The digital processing system also performs a continuous assessment of entropy quality by monitoring the statistical properties of the processed data streams. If predefined entropy quality thresholds are exceeded, corrective measures are initiated, including adjusting oscillator parameters, changing the sampling rate, or temporarily suppressing key generation. This ensures compliance with cryptographic entropy requirements throughout the device's entire operating life.

[0058] The conditional entropy data is fed into a key generation structure configured to generate cryptographic keys of predefined length. This structure combines the entropy data with internal state diversification data stored in secure memory to generate session keys, master keys, or seed values ​​for cryptographic protocols. The generated keys are stored in secure memory protected against unauthorized reading and physical access.

[0059] The system also includes an interface unit that allows external cryptographic processors or secure communication subsystems controlled access to the generated keys. The access control logic ensures that the key material is only released in encrypted or usage-restricted form, thus preventing the direct disclosure of the raw keys.

[0060] The drawing and the preceding description illustrate embodiments. Those skilled in the art will recognize that one or more of the described elements can be combined to form a single functional element. Alternatively, certain elements can be divided into several functional elements. Elements of one embodiment can be added to another. For example, the process flows described here can be modified and are not limited to the manner described herein. Furthermore, the actions of a flowchart need not be performed in the sequence shown; nor do all actions necessarily need to be carried out. Actions that do not depend on other actions can be performed in parallel with the other actions. The scope of protection of the embodiments is in no way limited by these specific examples. Numerous variations, whether explicitly stated in the description or not, such as...Differences in structure, dimensions, and materials are possible. The scope of protection of the embodiments is at least as comprehensive as described by the following claims.

[0061] The advantages, other benefits, and problem solutions have been described above with reference to specific embodiments. However, the advantages, benefits, problem solutions, and any components that can effect or enhance an advantage, benefit, or solution are not to be construed as critical, necessary, or essential features or components of the claims. REFERENCES 100 A System for Secure Cryptographic Key Generation Using Chaotic Oscillator-Based Entropy Units. 102 Structural Design 104 One or more chaotic oscillator units 106 Signal Acquisition Unit 108 conversion unit 110 Processing unit 112 Key derivation unit 114 Secure storage space

Claims

[1] A system for secure cryptographic key generation using chaotic oscillator-based entropy units, the system comprising: a housing designed for integration into a machine or electronic device; one or more chaotic oscillator units physically arranged within the housing, each chaotic oscillator unit comprising a nonlinear electronic circuit configured to operate in a chaotic dynamic regime to generate an aperiodic analog signal sensitive to initial conditions and intrinsic circuit noise; a signal acquisition unit electrically connected to one or more chaotic oscillator units and configured to receive the aperiodic analog signal, wherein the signal acquisition unit includes an analog conditioning circuit configured to normalize the signal amplitude and limit the signal bandwidth to a predefined operating range; a converter unit that is electrically coupled to the signal acquisition unit and is configured to sample the processed analog signal at time-varying sampling intervals to generate a digital entropy data stream; a processing unit comprising one or more processors operationally linked to a non-volatile memory, wherein the processing unit is configured to perform entropy conditioning operations on the digital entropy data stream to suppress distortions and reduce temporal correlation; a key generation unit that is operationally coupled with the processing unit and configured to convert conditional entropy data into cryptographic key material of a predefined key length; and a secure storage unit that is operationally connected to the key generation unit and is configured to store the cryptographic key material while preventing unauthorized external access, wherein the system is configured to generate cryptographic keys from physically chaotic behavior without relying on deterministic, purely software-based entropy sources. [2] System according to claim 1, wherein each chaotic oscillator unit comprises a feedback network consisting of nonlinear electronic components arranged to amplify microscopic variations caused by thermal noise, component mismatch and electrical disturbances, such that the resulting analog signal exhibits broadband spectral characteristics and a non-periodic temporal evolution over extended operating periods. [3] System according to claim 1, wherein the signal acquisition unit further comprises an isolation circuit configured to electrically decouple the chaotic oscillator units from external signal paths and thereby prevent deterministic excitation, electromagnetic injection or modulation of the power supply from influencing the chaotic operating state. [4] System according to claim 1, wherein the conversion unit is configured to vary the sampling times based on an internally generated time reference derived from a secondary entropy-dependent process, such that the digital entropy data stream is resistant to reconstruction by fixed-interval sampling analysis. [5] System according to claim 1, wherein the processing unit is further configured to perform a continuous evaluation of the entropy quality by calculating statistical parameters related to the bit distribution, transition density and temporal dependence, and to prevent key derivation if the evaluated entropy quality deviates from predefined acceptance thresholds stored in non-volatile memory. [6] System according to claim 5, wherein the processing unit, upon detection of reduced entropy quality, initiates corrective measures which include adjusting the oscillator bias conditions, changing the sampling intervals or temporarily interrupting key generation until acceptable entropy properties are restored. [7] System according to claim 1, wherein the entropy conditioning operations performed by the processing unit comprise a multi-stage transformation of the digital entropy data stream by means of non-linear mixing, temporal reordering and state diversification derived from internal memory values ​​which are not accessible outside the housing. [8] System according to claim 1, wherein the key generation unit is configured to generate cryptographic keys for at least one of the following operations: symmetric encryption, asymmetric key generation or authentication token creation, and wherein the key generation unit prevents the direct disclosure of conditional entropy data to an external interface. [9] System according to claim 1, wherein the secure storage unit comprises a protected storage circuit configured to restrict read access based on internal authorization conditions enforced by the processing unit, and further configured to automatically delete stored cryptographic key material upon detection of a tampering state. [10] System according to claim 1, further comprising a tamper detection unit arranged inside the housing and configured to monitor at least voltage deviations, temperature fluctuations or indicators of physical intrusion, wherein the tamper detection unit is operationally connected to the secure storage unit to initiate a key zeroing when an abnormal condition is detected.

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