Key protection method and device based on PUF chip and storage medium

Abstract

The embodiment of the invention provides a key protection method and device based on a PUF chip and a storage medium, and the method comprises the steps: in a key generation stage, generating a random challenge sequence based on physical environment parameters, and transmitting the challenge sequence to the PUF chip; the PUF chip generates a corresponding PUF response according to the received challenge sequence, and the PUF response is processed by a hash function to generate an initial key material; and in combination with the initial secret key material and the message information of the equipment, secret keys with different requirements are derived, so that the flexibility and the security of secret key generation are improved, multi-purpose secret keys are derived as required, the relevance between the secret keys is reduced, and the anti-attack defense capability is improved.

Description

Technical Field

[0001] The present application relates to the field of information security technology, and in particular, to a key protection method, device, and storage medium based on a PUF chip. Background Art

[0002] In the digital age, information security is a core element in ensuring system and data security. As the key to information security, the security of keys is of vital importance. Traditional key protection methods mainly rely on encryption algorithms and storage media, but these methods have many security risks. For example, keys stored in hardware are vulnerable to physical attacks such as side-channel attacks and reverse engineering, resulting in key leakage. At the same time, with the improvement of computing power and the development of attack technologies, encryption algorithms may also be cracked.

[0003] The emergence of physically unclonable function (PUF) chips provides a new idea for key protection. PUF chips utilize the inevitable physical differences in the chip manufacturing process to generate unique and unpredictable responses, and have natural anti-cloning and anti-reverse engineering characteristics.

[0004] However, existing key protection schemes based on PUF chips still have deficiencies. For example, the randomness and security of key generation need to be improved. For example, a key protection method based on physically unclonable function disclosed in the existing patent document CN105007285B encodes a key seed through an error-correcting code, and XORs it with the PUF fingerprint to generate auxiliary data. When reconstructing the key, the key seed is restored through error-correcting code decoding to generate the key. The generation of this key depends on a single key seed, and because the auxiliary data is directly associated with the PUF fingerprint, if the key seed is leaked, there may be a risk of multiple keys being cracked.

[0005] Therefore, it is of great significance to develop a more secure and efficient key protection solution based on PUF chips. Summary of the Invention

[0006] According to an embodiment of the present application, a more secure and efficient key protection method based on a PUF chip is provided. By dynamically generating a challenge sequence and binding it with context device message information, the flexibility and security of key generation are enhanced, and the global risk caused by the leakage of a single key seed is avoided.

[0007] In a first aspect of the present application, a key protection method based on a PUF chip is provided, including a key generation stage, a key storage stage, a key usage stage, and a key update stage. Among them, in the key generation stage, the steps of generating a key include:

[0008] Step 10: Generate a random challenge sequence based on physical environment parameters and send the challenge sequence to the PUF chip;

[0009] Step 20: The PUF chip generates a corresponding PUF response according to the received challenge sequence, and the PUF response is processed by a hash function to generate initial key material;

[0010] Step 30: Combine the initial key material and the message information of the device to derive keys for different requirements.

[0011] In a possible implementation manner, in the step 10, generating a random challenge sequence includes a plurality of challenge elements. Specifically,

[0012] C = {c1, c2,..., c M}, c i ∈ {0, 1} k

[0013] where C represents the challenge sequence, M represents the number of challenge elements; c i represents each challenge element in the challenge sequence and is a binary vector of length k.

[0014] In a possible implementation manner, in the step 10, generating the random challenge sequence based on physical environment parameters includes:

[0015] Generating each of the challenge elements based on real-time physical environment parameters, and then combining each of the challenge elements to generate a set of random challenge sequences.

[0016] In a possible implementation manner, the generating step of generating each of the challenge elements based on real-time physical environment parameters includes:

[0017] Step 101: Normalize the real-time physical environment parameters;

[0018] Step 102: Design a fusion environment parameter value α i through a dynamic coupling function;

[0019] Step 103: The initial value is driven by the fusion environment parameter value α i to construct a discretized Logistic chaotic map, and the chaotic map value of the third iteration is taken as the chaotic output value;

[0020] Step 104: Convert the chaotic map value of the third iteration into a binary challenge element.

[0021] In a possible implementation manner, the physical environment parameters include electromagnetic interference signal E, temperature T, humidity H, and timestamp t.

[0022] In a possible implementation, in step 20, before the PUF chip generates a corresponding PUF response according to the received challenge sequence, the challenge sequence is first preprocessed by challenge verification to check whether the length and format of the challenge sequence conform to the PUF interface specification;

[0023] Before performing a hash function process on the PUF response, error correction processing is also included for the PUF response.

[0024] In a possible implementation, in step 30, by combining the initial key material and the message information of the device, keys with different requirements are derived. The specific steps are as follows:

[0025] Step 301: Encode the message information of the device to obtain a device message encoding result;

[0026] Step 302: Perform an exclusive OR operation on the initial key material and the device message encoding result;

[0027] Step 303: Generate keys with different requirements through a one-way hash enhancement function.

[0028] In a possible implementation, in the key storage stage, the storage methods for keys include implicit storage and encrypted storage;

[0029] In the key update stage, it includes regular update and trigger update. When the key needs to be updated, the steps of generating keys in the key generation stage are used for key update.

[0030] In a second aspect of the present application, an electronic device is provided. The electronic device includes: a memory and a processor. A computer program is stored on the memory, and when the processor executes the program, the method of the first aspect of the embodiments of the present application is implemented.

[0031] In a third aspect of the present application, a computer-readable storage medium is provided, on which a computer program is stored. When the program is executed by a processor, the method of the first aspect of the embodiments of the present application is implemented.

[0032] Compared with the prior art, the advantages of the present application are as follows:

[0033] The present application provides a more secure and efficient key protection method based on a PUF chip. By dynamically generating a challenge sequence and combining it with context device message information for binding, the flexibility and security of key generation are enhanced, and the global risk caused by the leakage of a single key seed is avoided.

[0034] Specifically, in the key generation phase, a random challenge sequence is generated based on physical environment parameters, and the challenge sequence is sent to the PUF chip; the PUF chip generates a corresponding PUF response according to the received challenge sequence, and the PUF response is processed by a hash function to generate initial key material; combining the initial key material and the message information of the device, keys with different requirements are derived, improving the flexibility and security of key generation, supporting on-demand derivation of multi-purpose keys, reducing the correlation between keys, and enhancing the anti-attack ability.

[0035] It should be understood that the content described in the summary of the invention section is not intended to limit the key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In combination with the accompanying drawings and with reference to the following detailed description, the above and other features, advantages and aspects of the embodiments of the present application will become more apparent. In the drawings, the same or similar reference numerals represent the same or similar elements, where:

[0037] Figure 1 is a framework diagram of the key protection method based on the PUF chip in the embodiment of the present application;

[0038] Figure 2 is a schematic diagram of the overall process of generating keys in the key generation phase in the embodiment of the present application;

[0039] Figure 3 is a schematic diagram of the process of generating each of the challenge elements based on real-time physical environment parameters in the embodiment of the present application;

[0040] Figure 4 is a schematic diagram of the process of generating keys with different requirements based on the combination of the initial key material and the message information of the device in the embodiment of the present application;

[0041] Figure 5 is a schematic diagram of the structure of a terminal device or a server suitable for implementing the embodiments of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] To make the objectives, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present disclosure. Apparently, the described embodiments are some, but not all, of the embodiments of the present disclosure. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present disclosure without creative efforts shall fall within the protection scope of the present disclosure.

[0043] In addition, the technical solutions between various embodiments of the present application can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present application.

[0044] In the key generation stage of the present application, a random challenge sequence is generated based on physical environment parameters and sent to the PUF chip; the PUF chip generates a corresponding PUF response according to the received challenge sequence, and the PUF response is processed by a hash function to generate initial key material; by combining the initial key material and the message information of the device, keys with different requirements are derived, improving the flexibility and security of key generation, supporting on-demand derivation of multi-purpose keys, reducing the correlation between keys, enhancing the anti-attack ability, and avoiding the risk that multiple keys may be cracked due to the leakage of a single key seed in the prior art.

[0045] Figure 2 It is a schematic diagram of the overall process of generating keys in the key generation stage of the embodiments of the present application;

[0046] See Figure 1 , the present application provides a key protection method based on a PUF chip, including a key generation stage, a key storage stage, a key usage stage, and a key update stage;

[0047] Among them, with reference to Figure 2 , in the key generation stage, the steps of generating keys include:

[0048] Step 10: Generate a random challenge sequence based on physical environment parameters and send the challenge sequence to the PUF chip;

[0049] In this embodiment, the physical environment parameters refer to various measurable parameters in the real physical world, such as electromagnetic interference signal E, temperature T, humidity H, and timestamp t, etc., and these parameters change with time and environment.

[0050] Utilize the real-time change and uncertainty of physical environment parameters, and generate a series of random challenge elements C i ∈ {0, 1} k (k-bit binary sequence), and the data sequence formed by these challenge element sets is called the challenge sequence. The challenge sequence is usually a string of binary codes, which has randomness and unpredictability. Specifically,

[0051] C = {c1, c2,..., c M}, c i ∈ {0, 1} k

[0052] Among them, C represents the challenge sequence, and M represents the number of challenge elements; c i represents the i-th challenge element in the challenge sequence and is a binary vector of length k. That is to say, each c i is composed of k binary bits (0 or 1). For example, when k = 3, c i may be one of 8 possible combinations such as (0, 0, 0), (0, 0, 1), (0, 1, 0), etc.

[0053] The generated random challenge sequence is transmitted to the PUF chip through a communication interface (such as SPI, I2C, etc.). After receiving the challenge sequence, the PUF chip generates a corresponding response sequence according to its physical characteristics.

[0054] The PUF chip is a physically unclonable function chip, which is a security chip that uses the inevitable physical differences in the chip manufacturing process to generate a unique response. Each PUF chip has its unique physical structure, and this physical structure will generate a unique PUF response to the input challenge sequence.

[0055] The whole process generates random challenges based on the dynamic changes of physical environment parameters, and then uses the physical uniqueness of the PUF chip to generate corresponding responses, so as to achieve highly secure key management.

[0056] In a preferred embodiment, as Figure 3 shown, based on the real-time physical environment parameters, a series of random challenge elements C are generated through a specific algorithm generation step i , and the specific algorithm generation step includes:

[0057] Step 101, normalize the real-time physical environment parameters;

[0058] Specifically, the physical environment parameters include, but are not limited to, electromagnetic interference signal E, temperature T, humidity H, and timestamp t. Map each parameter to the [0, 1] interval to eliminate the dimension difference. The mapping formula for specific parameters is as follows:

[0059]

[0060] Among them, represents the electromagnetic interference signal mapping value, E min and E max respectively represent the minimum value and the maximum value of the electromagnetic interference signal E. In this mapping formula, the actual value of the electromagnetic interference signal E is mapped to the [0, 1] interval through a linear transformation. When E = E min , When E = E max ,

[0061] Represents the temperature mapping value, T min and T max respectively represent the minimum and maximum values of temperature T. In this mapping formula, the actual value of T is linearly mapped to the interval [0, 1].

[0062] Represents the humidity mapping value, H min and H max respectively represent the minimum and maximum values of humidity H. In this mapping formula, the actual value of H is linearly transformed to the interval [0, 1].

[0063] Represents the timestamp mapping value, t low Represents the lower part of the timestamp parameter. Perform a modulo 2 16 operation on it, divide the result by 2 16 -1, so as to map the processed value to the interval [0, 1].

[0064] The reason for normalizing the parameter data is to map the data of different physical environment parameters to the interval [0, 1], so as to eliminate the differences caused by different dimensions among the parameters.

[0065] Step 102: Design the fused environmental parameter value α through a dynamic coupling function i ;

[0066] Specifically, the calculation formula of the dynamic coupling function is as follows:

[0067]

[0068] Among them, the fused environmental parameter value α i always takes values in the interval [0, 1). Specifically, by multiplying the electromagnetic interference signal mapping value and the humidity mapping value by the sine and cosine functions respectively and then adding them, the preliminary fusion of physical environment parameters is realized, and then a modulo operation is performed to limit the result of the value range of the fused environmental parameter value α i within the range of [0, 1).

[0069] Step 103: The initial value is driven by the fused environmental parameter value α i to construct a discretized Logistic chaotic map, and take the chaotic map value of the third iteration as the chaotic output value;

[0070] Specifically, the calculation formula of the Logistic chaotic map is as follows:

[0071] xn+1 = μ·x n (1 - x n ), x0 = α i

[0072]

[0073] where x n is the state value of the nth iteration, μ is the dynamic control coefficient, and the initial value x0 is driven by α i , i.e., x0 = α i ; preferably, it is required to take x3 as the chaotic output value after 3 iterations, that is, starting from the initial value x0 = α i and performing 3 iterations according to x n+1 = μ·x n (1 - x n ). The specific iterations are as follows:

[0074] The 1st iteration: x1 = μ·x0(1 - x0) = μ·α i (1 - α i );

[0075] The 2nd iteration: x2 = μ·x1(1 - x1) = μ·[μ·α i (1 - α i )][1 - μ·α i (1 - α i )]

[0076] The 3rd iteration: x3 = μ·x2(1 - x2). Substitute the chaotic map x2 of the second iteration above to obtain the chaotic map x3 of the third iteration.

[0077] Step 104: Convert the chaotic map value of the third iteration into a binary challenge element.

[0078] Specifically, convert the chaotic map value x3 of the third iteration into a k-bit binary sequence, that is, obtain the challenge element C i as follows:

[0079]

[0080] where CRC4 represents a 4-bit cyclic redundancy check code, and the input is the concatenation of the original byte streams of the electromagnetic interference signal E, temperature T, and humidity H, which resists instantaneous noise interference; Binarize represents converting an integer into a k-bit binary, padding zeros at the high bits, and then performing an exclusive OR operation to ensure the unpredictable randomness and security of the challenge sequence.

[0081] Thus, in this embodiment, through the three-level structure of physical environment parameter coupling → chaotic perturbation → quantization confusion, the physical unclonability and environmental relevance of the challenge sequence are realized, further ensuring the flexibility and security of key generation.

[0082] Step 20: The PUF chip generates a corresponding PUF response according to the received challenge sequence, and this PUF response is processed by a hash function to generate the initial key material.

[0083] Optionally, when the PUF chip receives the challenge sequence, it first performs preprocessing of challenge verification on the challenge sequence to ensure sufficient entropy and avoid being predicted. Specifically, it can verify whether the length and format of the challenge sequence conform to the PUF interface specification and discard illegal challenges. If the length of the challenge sequence is insufficient, extended bits can be generated through the PRNG to meet the minimum trigger requirement of the PUF response.

[0084] Furthermore, before processing the PUF response with the hash function, error correction processing is also included for the PUF response.

[0085] Specifically, since there may be noise in the PUF response, such as response differences caused by temperature changes, error correction processing is required. Error correction processing can be performed by using an error correction code (ECC) or a fuzzy extractor (Fuzzy Extractor) to ensure that even with minor changes, the generated responses can remain consistent.

[0086] The processed PUF response is used as the input of the hash function. Through the calculation of the hash function, a hash value with a fixed length is obtained, and this hash value is used as the initial key material. The selection of the hash function needs to meet cryptographic security requirements, such as SHA-256, to ensure that the possibly long PUF response can be compressed or converted into a key with a fixed length and any statistical bias can be eliminated.

[0087] Step 30: Combine the initial key material and the message information of the device to derive keys with different requirements.

[0088] Combine Figure 4 As shown, combine the initial key material and the message information of the device to derive keys with different requirements. The specific steps are as follows:

[0089] Step 301: Encode the message information of the device to obtain the device message encoding result.

[0090] Specifically, the message information of the device includes, but is not limited to, the device ID, the device temperature T ’ and the device humidity H’, and perform information encoding on it. Compress the device temperature T ’ and the device humidity H’ into two bytes (8-bit precision), that is:

[0091] T byte = T' × 2.55 (mapped to 0 - 255);

[0092] H byte = H' × 2.55 (mapped to 0 - 255);

[0093] Device message encoding result: D data = D ID || T byte || H byte ∈ {0, 1} 80 .

[0094] Step 302: Perform an exclusive OR operation on the initial key material and the device message encoding result;

[0095] Specifically, the initial key material K base and the device message encoding result D data are linearly XOR - mixed, and the mixed key result K mix has the following calculation formula:

[0096]

[0097] where K base [i] is a 256 - bit key, which is divided into 8 32 - bit words. The index i ranges from 0 to 7 and is used to select the i - th 32 - bit word in the 256 - bit key.

[0098] D data [j] is an 80 - bit device data, which is divided into 10 8 - bit bytes. The index j ranges from 0 to 9 and is used to select the j - th 8 - bit byte in the 80 - bit device data.

[0099] Step 303: Generate keys for different requirements, such as encryption keys and signature keys, through a one - way hash enhancement function.

[0100] To better eliminate the statistical bias of the mixed key result, a one - way hash enhancement function is used to ensure non - traceable forward security, that is, the finally generated key K final cannot be traced back to K mix , specifically:

[0101] K final = SHA - 256(K mix || D data );

[0102] In a possible implementation, during the key storage phase, the storage methods of the keys include implicit storage and encrypted storage;

[0103] Specifically, part of the secret key is stored in the PUF chip in an implicit form. Only when a correct challenge is received can the corresponding key be generated through the PUF response. This method avoids the plaintext storage of the key in the storage medium and reduces the risk of key leakage.

[0104] For the keys that need to be saved in an external storage device, the encryption key generated by the PUF chip is used to encrypt them. The encryption algorithm can select symmetric encryption algorithms such as AES to ensure the confidentiality of the key during storage.

[0105] The dual storage mechanism takes into account the lightweight requirements of resource-constrained devices and the confidentiality of keys, reducing the threats of physical attacks and side-channel attacks. Compared with the auxiliary data in the prior art, although it does not need to be securely stored, if an attacker obtains the relationship between the auxiliary data and the key seed encoding, it is still possible to crack the PUF fingerprint through reverse calculation. The embodiments of the present application eliminate the risk of key plaintext exposure through implicit storage and dynamic encryption, and strengthen the security of the storage link.

[0106] In the key usage stage, the embodiments of the present application introduce real-time security environment monitoring, such as electromagnetic interference and abnormal temperature and humidity detection, and trigger suspension or key update. That is to say, through environment monitoring, potential attack behaviors can be actively identified, the dynamic protection ability can be enhanced, multi-dimensional security protection can be provided, and it can be extended from the key itself to the usage environment, significantly improving the system's response speed to physical attacks and abnormal states.

[0107] In the key update stage, it includes regular update and trigger update, combined with Figure 1 As shown, when the key needs to be updated, the steps of generating the key in the key generation stage are adopted for key update.

[0108] Specifically, the embodiments of the present application adopt a mechanism combining regular update and trigger update to achieve enhanced active defense ability; the regular update can update the key according to a preset period (such as monthly); the trigger update is to update immediately when a security event (such as an attack attempt) is detected.

[0109] Active regular update helps to reduce the risk of long-term key exposure. At the same time, rapid response to threats is achieved through event triggering, and the steps of generating the key in the key generation stage of the present application are adopted for key update, greatly improving the system's security defense ability.

[0110] In addition, before the key usage stage, the present application also designs and implements multi-level authorization verification and modular design to achieve fine-grained permission management. The multi-level authorization verification is such as device identity, user identity, and application permissions; the modular design is such as an independent security controller and a preprocessing module.

[0111] In summary, through dynamic key derivation, implicit storage, environmental monitoring, hybrid update strategy, and modular authorization, the embodiments of the present application have achieved the following breakthroughs:

[0112] By dynamically generating a challenge sequence and binding it in combination with context device message information, the flexibility and security of key generation are enhanced;

[0113] From key generation to full-link protection during use, the leakage risk is reduced and security is improved;

[0114] Supports multi-purpose key derivation and scenario adaptation, enhancing adaptation flexibility;

[0115] Through physical environment monitoring combined with key generation and hybrid update, active defense capabilities are achieved;

[0116] Effectively solves the deficiencies of existing solutions in key correlation, storage security, dynamic protection, and permission control, and provides a better solution for scenarios with high security requirements such as the Internet of Things and industrial control.

[0117] Figure 5 The structural schematic diagram of the terminal device or server suitable for implementing the embodiments of the present application is shown.

[0118] As Figure 5 shown, the terminal device or server includes a central processing unit (CPU) 501, which can perform various appropriate actions and processes according to the program stored in the read-only memory (ROM) 502 or the program loaded from the storage section 508 into the random access memory (RAM) 503. In the RAM 503, various programs and data required for the operation of the terminal device or server are also stored. The CPU 501, ROM 502, and RAM 503 are connected to each other via a bus 504. The input / output (I / O) interface 505 is also connected to the bus 504.

[0119] The following components are connected to the I / O interface 505: an input section 506 including a keyboard, a mouse, etc.; an output section 507 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 508 including a hard disk, etc.; and a communication section 509 including a network interface card such as a LAN card, a modem, etc. The communication section 509 performs communication processing via a network such as the Internet. The drive 510 is also connected to the I / O interface 505 as required. A removable medium 511, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 510 as required, so that the computer program read from it can be installed into the storage section 508 as required.

[0120] In particular, according to an embodiment of the present application, the above method flow steps can be implemented as a computer software program. For example, an embodiment of the present application includes a computer program product, which includes a computer program carried on a machine-readable medium, and the computer program contains program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 509, and / or installed from the removable medium 511. When the computer program is executed by the central processing unit (CPU) 501, the above functions defined in the system of the present application are executed.

[0121] It should be noted that the computer-readable medium shown in the present application can be a computer-readable signal medium or a computer-readable storage medium or any combination of the two. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples of the computer-readable storage medium can include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, the computer-readable storage medium can be any tangible medium that contains or stores a program, and the program can be used by or in combination with an instruction execution system, apparatus, or device. In the present application, the computer-readable signal medium can include a data signal propagated in a baseband or as part of a carrier wave, which carries the computer-readable program code. Such a propagated data signal can take various forms, including but not limited to electrical electromagnetic interference signals, optical signals, or any suitable combination of the above. The computer-readable signal medium can also be any computer-readable medium other than the computer-readable storage medium, and the computer-readable medium can send, propagate, or transmit a program for use by or in combination with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted by any suitable medium, including but not limited to: wireless, wire, optical cable, RF, etc., or any suitable combination of the above.

[0122] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to various embodiments of the present application. In this regard, each block in the flowchart or block diagram may represent a module, a segment of a program, or a part of code, and the foregoing module, segment of a program, or part of code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than that marked in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, as well as combinations of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system that performs the specified functions or operations, or can be implemented by a combination of dedicated hardware and computer instructions.

[0123] The units or modules described in the embodiments of the present application can be implemented in software or in hardware. The described units or modules can also be provided in a processor. Among them, the names of these units or modules do not constitute a limitation to the units or modules themselves in some cases.

[0124] On the other hand, the present application also provides a computer-readable storage medium, which can be included in the electronic device described in the above embodiments; or can exist separately without being assembled into the electronic device. The above computer-readable storage medium stores one or more programs, and when the foregoing programs are executed by one or more processors, they implement the methods described in the present application.

[0125] The above description is only a preferred embodiment of the present application and an explanation of the applied technical principles. Those skilled in the art should understand that the scope of the application involved in the present application is not limited to the technical solutions formed by the specific combination of the above technical features, and should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the foregoing application concept. For example, technical solutions formed by mutually replacing the above features with (but not limited to) technical features having similar functions in the present application.

Claims

1. A key protection method based on a PUF chip, comprising a key generation phase, a key storage phase, a key use phase and a key update phase, characterized in that: include: In the key generation phase, the steps of generating a key include: Step 10: Generate a random challenge sequence based on the physical environment parameters and send the challenge sequence to the PUF chip; Step 20: The PUF chip generates a corresponding PUF response according to the received challenge sequence, and the PUF response is processed by a hash function to generate an initial key material; Step 30: Combine the initial key material and the message information of the device to derive keys of different requirements.

2. The key protection method based on PUF chip according to claim 1, characterized in that: In step 10, a random challenge sequence is generated including multiple challenge elements, specifically, C={c1,c2,...,c M },c i ∈{0,1} k Where C represents the challenge sequence, M represents the number of challenge elements; c i Represents each challenge element in the challenge sequence, which is a binary vector of length k.

3. The key protection method based on PUF chip according to claim 2 is characterized in that: In step 10, generating a random challenge sequence based on physical environment parameters includes: Each of the challenge elements is generated based on real-time physical environment parameters, and then each of the challenge elements is aggregated to generate a set of random challenge sequences.

4. The key protection method based on PUF chip according to claim 3 is characterized in that: The step of generating each of the challenge elements based on real-time physical environment parameters includes: Step 101, normalizing the real-time physical environment parameters; Step 102: Design the fusion environment parameter value α through the dynamic coupling function i ; Step 103: The initial value is determined by the fusion environment parameter value α i Drive, construct a discretized Logistic chaotic map, and take the chaotic map value of the third iteration as the chaotic output value; Step 104: Convert the chaotic map value of the third iteration into a binary challenge element.

5. The key protection method based on PUF chip according to claim 1, characterized in that: The physical environment parameters include an electromagnetic interference signal E, a temperature T, a humidity H and a timestamp t.

6. The key protection method based on PUF chip according to claim 1, characterized in that: In the step 20, before the PUF chip generates a corresponding PUF response according to the received challenge sequence, it first performs challenge verification preprocessing on the challenge sequence to verify whether the length and format of the challenge sequence conform to the PUF interface specification; Before performing hash function processing on the PUF response, the method further includes performing error correction processing on the PUF response.

7. The key protection method based on PUF chip according to claim 1, characterized in that: In step 30, the initial key material and the message information of the device are combined to derive keys of different requirements. The specific implementation steps are as follows: Step 301: Encode the message information of the device to obtain a device message encoding result; Step 302: Perform an XOR operation on the initial key material and the device message encoding result; Step 303: Generate keys for different requirements through a one-way hash enhancement function.

8. The key protection method based on PUF chip according to claim 1, characterized in that: In the key storage stage, the key storage methods include implicit storage and encrypted storage; In the key updating phase, which includes periodic updating and triggered updating, when the key needs to be updated, the key is updated by adopting the key generation step in the key generation phase.

9. An electronic device comprising a memory and a processor, wherein a computer program is stored in the memory, wherein: When the processor executes the computer program, the method according to any one of claims 1 to 8 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 8 is implemented.

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