Encryption method and device for nondestructive testing of DICOM image file and medium

Abstract

The invention discloses an encryption method for nondestructive testing of a DICOM (Digital Imaging and Communications in Medicine) image file, which comprises the following steps of: reading the DICOM file, acquiring image data information and other data element information and inputting; performing feature extraction on the input information to obtain a feature sequence; preprocessing the feature sequence into an initial value required by three-layer chaotic mapping; constructing a chaotic mapping function according to a three-layer mode; processing the initial value obtained by preprocessing to obtain encrypted image data; symmetric encryption is carried out on other data element information of the DICOM file to obtain a secret key; symmetrically encrypting all data element information except the image to obtain an encrypted data sequence; and recombining the encrypted image data and the encrypted data sequence to obtain a DICOM encrypted file. According to the method, a mode of combining multi-level chaotic mapping and symmetric encryption is adopted in the encryption process, and the effect of comprehensively protecting image information and other data element information in the DICOM file can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of image encryption, and in particular to an encryption method, device and medium for a non-destructive testing DICOM image file. Background Art

[0002] X-ray detection data contains a large amount of key sensitive information of nuclear power plants. Ensuring its data security is an important part of nuclear safety. While traditional physical films have greatly facilitated film storage, analysis, and management during the digital transformation process, they have also brought challenges to the confidentiality of digital information. Therefore, a reliable encryption method is needed to process the digital information of the film to ensure the security of key sensitive information of nuclear power plants.

[0003] In the prior art, the commonly used security encryption technology in the field of image encryption is generally to use chaotic mapping to build a system to encrypt images. Since the chaotic system exhibits non-periodic, non-convergent, and irregular motion in a deterministic system, its characteristics are consistent with the nature of the overall irregular changes in the ciphertext caused by slight changes in the plaintext required for encryption. Therefore, after integrating the chaotic system with other algorithms of modern cryptography, an encryption method with significant effects and stronger randomness can be obtained.

[0004] At present, the encryption application direction of chaotic systems is focused on simple image encryption. However, for the field of non-destructive testing, in addition to the film image data itself, the related data elements also have the need for encryption protection to prevent potential attackers from stealing relevant information.

[0005] Therefore, the field of digital nondestructive testing in nuclear power plants requires an encryption method that can adapt to the nondestructive testing file format and can jointly encrypt and collaboratively protect film image data and related data elements to achieve secure protection of digital information in nuclear power plants.

[0006] To this end, the present application proposes a non-destructive testing DICOM image file encryption method to solve the above technical problems. Summary of the invention

[0007] The main purpose of the present invention is to provide an encryption method for non-destructive testing DICOM image files. Aiming at the current demand for digital encryption of non-destructive testing in nuclear power plants, based on the theory and research of digital information encryption in the medical field, the chaotic mapping algorithm is combined with the traditional encryption method and the image encryption step to solve the technical problems raised in the background technology. The reliability of the encryption system is ensured by utilizing the randomness and initial value sensitivity of chaos, thereby ensuring the encryption security of the digital negative film for non-destructive testing.

[0008] The present invention adopts the following technical solutions to solve the above technical problems:

[0009] A method for encrypting a DICOM image file for non-destructive testing includes the following specific steps:

[0010] Step S1. Read the DICOM file, obtain image data information and other data element information, and input them as plain text image P and data sequence D;

[0011] Step S2. Extract the input information through the SHA-512 algorithm to obtain a unique feature sequence;

[0012] Step S3. preprocessing the feature sequence into the initial value required for the three-layer chaotic mapping;

[0013] Step S4. constructing a chaotic mapping function in a three-layer manner, wherein the first layer is a Hénon two-dimensional chaotic mapping, the second layer is a Logistic one-dimensional chaotic mapping, and the third layer is a Tent one-dimensional chaotic mapping;

[0014] Step S5. The initial value obtained by preprocessing is put into Hénon mapping, and the chaotic mapping is polled and calculated for the same round according to the length of the image data and other metadata, and finally a chaotic sequence of equal length or slightly longer than the image data is obtained, and the original image is subjected to multiple rounds of improved Arnold scrambling operation according to the chaotic sequence;

[0015] Step S6. According to the characteristics of the Logistics mapping and the Tent mapping, the scrambled images are XOR diffused using the initial values ​​obtained by preprocessing to obtain encrypted image data;

[0016] Step S7. For other data element information of the DICOM file, select the extracted feature sequence according to the rules, perform symmetric encryption with key as the key, and obtain the corresponding key that can be used for symmetric encryption;

[0017] Step S8. For all data element information except the image, use the key to complete symmetric encryption to obtain an encrypted data sequence;

[0018] Step S9: The encrypted image data and the encrypted data sequence are reassembled into a file according to the DICOM standard file format to obtain a DICOM encrypted file that complies with the file specification but has encrypted content.

[0019] Preferably, the specific operation steps in step S3 include:

[0020] a1. Preprocess the feature sequence into four sets of parameters {p1,u1}, {p2,u2}, {p3,u3}, {p4,u4};

[0021] a2. The parameters {p1,u1} and {p2,u2} are processed as follows to obtain initial values, so that these initial values ​​can guide the subsequent items obtained by the mapping function to have chaotic characteristics:

[0022]

[0023] a3. The parameters {p3,u3} and {p4,u4} are processed as follows to obtain initial values, so that these initial values ​​can guide the subsequent items of the mapping function to have chaotic characteristics;

[0024]

[0025] Preferably, the specific operation steps in step S5 include:

[0026] b1. Bring the pre-processed initial values ​​of the parameters {p3, u3} and {p4, u4} into the first layer of two-dimensional chaotic mapping, calculate the rounds at least equal to the polling number i of the scrambling algorithm, and obtain two chaotic sequences A1 and A2 with a length not less than i;

[0027] b2. Take the last i items of the chaotic sequences A1 and A2, perform i improved Arnold scrambling operations on the plaintext image P, and obtain the scrambled image P1.

[0028] Preferably, the specific operation steps of improving the Arnold scrambling operation in step S5 include:

[0029] c1. Before the operation, determine the block size k and step size s of the sliding window. The block size k is the minimum value of the image length and width, and the step size s is the greatest common divisor of the image length and width. Then, perform an Arnold scrambling operation on the original image matrix from the upper left with a size of k×k.

[0030] c2. Slide rightward or downward by a distance s and perform another Arnold scrambling operation within the new k×k size until all pixels of the original image have been scrambled at least once, and then a round of scrambling is completed.

[0031] Preferably, the specific operation steps in step S6 include:

[0032] d1. Bring the initial values ​​of the parameters {p3,u3} and {p4,u4} after preprocessing into the one-dimensional chaotic mapping of the second and third layers, and calculate the rounds for at least the length l of the image data to obtain two chaotic sequences A3 and A4 with a length not less than l;

[0033] d2. Take the last item of chaotic sequence A3, use image diffusion algorithm on the scrambled image P1, and get the first diffusion image P2;

[0034] d3. Take the last item of chaotic sequence A4, use the image diffusion algorithm on the image P3 after the first diffusion, and obtain the encrypted image P3.

[0035] Preferably, the DICOM encrypted file in step S9 includes the following decryption steps:

[0036] L1. Obtain the feature sequence of the file through a secure private channel, and build a three-layer chaotic system according to the same operation as the encryption method to calculate and obtain the chaotic sequences at each level;

[0037] L2. After the encrypted image is subjected to the reverse diffusion operation of the third and second chaotic sequences respectively, it is subjected to the reverse scrambling algorithm of the two chaotic sequences obtained by the first chaotic mapping calculation to obtain the restored image data;

[0038] L3. Perform rule selection on the feature sequence, use the obtained key to symmetrically decrypt the data element sequence, restore the original data element information, and combine the restored image data into a decrypted DICOM file.

[0039] Preferably, after the decrypted DICOM file in the L3 step is obtained, it is also necessary to prove that the file restoration is valid. The specific proof steps include: extracting features from the obtained DICOM file using the SHA-512 algorithm, and comparing the obtained feature sequence with the feature sequence obtained from the private channel. If they are completely consistent, the restoration is proven to be valid.

[0040] Preferably, during the execution of the encryption method for non-destructive testing DICOM image files, it is assumed that both encryption and decryption parties have a reliable private channel transmission feature sequence, which can ensure that the feature sequence used for decryption is accurate to achieve image integrity verification.

[0041] A non-destructive testing DICOM image file encryption system, used to execute any of the above-mentioned non-destructive testing DICOM image file encryption methods, comprising:

[0042] Data transmission module, used for receiving or sending DICOM original image files, DICOM encrypted files and keys corresponding to the encrypted files;

[0043] DICOM image reading module, used to read DICOM files to obtain image data information and other data element information, and extract unique feature sequences;

[0044] A chaotic mapping encryption module is used to perform chaotic mapping encryption on the image data information according to a three-layer chaotic mapping function based on a feature sequence to obtain encrypted image data;

[0045] The symmetric encryption module is used to select other data element information based on the feature sequence and obtain the encrypted data sequence and the corresponding key after symmetric encryption;

[0046] A file combination module, used for recombining the encrypted image data and the encrypted data sequence to form a DICOM encrypted file;

[0047] The reverse decryption module is used to use the key to perform a decryption operation on the DICOM encrypted file according to the inverse operation of the encryption step to obtain the decrypted DICOM original image file.

[0048] On the other hand, the present invention further discloses a computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor executes the steps of the above method.

[0049] On the other hand, the present invention further discloses a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the above method.

[0050] It can be seen from the above technical solution that the present invention provides an encryption method for non-destructive testing DICOM image files. Compared with the prior art, the present invention has the following advantages:

[0051] 1. The present invention can ensure the consistency of file data before and after encryption by verifying the integrity of the decrypted file. Since feature extraction is performed on the decrypted image after it is obtained, the calculated feature value is compared with the feature value received by the private channel. In a completely consistent state, it can be ensured that the encrypted file transmitted this time is complete and has not been tampered with.

[0052] 2. The present invention can fully protect the image information and other data metadata in the DICOM file by combining multi-level chaotic mapping with symmetric encryption in the encryption process, and realize the encryption of image information and other data metadata in the DICOM file at the same time, thereby achieving the effect of improving data security and effectively preventing unauthorized access and data leakage.

[0053] 3. The present invention processes images using an improved Arnold scrambling operation and combines three layers of chaotic mapping (Hénon, Logistic, Tent) for image diffusion, which can completely disrupt the original image structure, thereby maintaining a high degree of data confidentiality and achieving effective protection of sensitive images.

[0054] 4. Aiming at the current demand for digital encryption of non-destructive testing in nuclear power plants, the present invention is based on the theory and research of digital information encryption in the medical field, combines the chaos mapping algorithm with the traditional encryption method and image encryption steps, and ensures the reliability of the encryption system by utilizing the randomness and initial value sensitivity of chaos, thereby ensuring the encryption security of the digital negative film used for non-destructive testing.

[0055] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become easy to understand through the following description. Of course, it is not necessary to achieve all of the advantages described above simultaneously for any product implementing the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0057] Figure 1 It is a schematic diagram of the overall steps of the method of the present invention;

[0058] Figure 2 It is a schematic diagram of the encryption algorithm of the present invention;

[0059] Figure 3 It is a schematic diagram of the decryption algorithm of the present invention;

[0060] Figure 4 Schematic diagram of the module structure of the system of the present invention. DETAILED DESCRIPTION

[0061] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. In the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0062] In the embodiment, see Figures 1 to 4 .

[0063] like Figure 1 and Figure 2As shown, in response to the current demand for digital encryption of non-destructive testing in nuclear power plants, an embodiment of the present invention proposes an encryption method for non-destructive testing DICOM image files. Based on the theory and research of digital information encryption in the medical field, a chaotic mapping algorithm is combined with a traditional encryption method and an image encryption step. By adopting a combination of multi-level chaotic mapping and symmetric encryption in the encryption process, it can fully protect the image information and other data meta-information in the DICOM file, and realize the encryption of the image information and other data meta-information in the DICOM file at the same time, thereby achieving the effect of improving data security, effectively preventing unauthorized access and data leakage, and by utilizing the randomness and initial value sensitivity of chaos, the reliability of the encryption system can be guaranteed, thereby ensuring the encryption security of the digital negative film for non-destructive testing.

[0064] Furthermore, the method specifically comprises the following steps:

[0065] Step S1. Read the DICOM file, obtain image data information and other data element information, and input them as plain text image P and data sequence D;

[0066] Step S2. Extract the input information through the SHA-512 algorithm to obtain a unique feature sequence;

[0067] Step S3. Preprocessing the feature sequence into the initial value required for the three-layer chaotic mapping, specifically including:

[0068] a1. Preprocess the feature sequence into four sets of parameters {p1,u1}, {p2,u2}, {p3,u3}, {p4,u4};

[0069] a2. The parameters {p1,u1} and {p2,u2} are processed as follows to obtain initial values, so that these initial values ​​can guide the subsequent items obtained by the mapping function to have chaotic characteristics:

[0070]

[0071] a3. The parameters {p3,u3} and {p4,u4} are processed as follows to obtain initial values, so that these initial values ​​can guide the subsequent items of the mapping function to have chaotic characteristics;

[0072]

[0073] Step S4. constructing a chaotic mapping function in a three-layer manner, wherein the first layer is a Hénon two-dimensional chaotic mapping, the second layer is a Logistic one-dimensional chaotic mapping, and the third layer is a Tent one-dimensional chaotic mapping;

[0074] Step S5. The initial value obtained by preprocessing is put into the Hénon map. According to the length of the image data and other metadata, the chaotic map is polled and calculated for the same round, and finally a chaotic sequence of equal length or slightly longer than the image data is obtained. The original image is scrambled for multiple rounds according to the chaotic sequence, which specifically includes:

[0075] b1. Bring the pre-processed initial values ​​of the parameters {p3,u3} and {p4,u4} into the first layer of two-dimensional chaotic mapping, calculate the rounds at least equal to the polling number i of the scrambling algorithm, and obtain two chaotic sequences A1 and A2 with a length not less than i. This chaotic sequence is obtained by continuous operation of the chaotic mapping with non-periodicity and non-convergence, and has randomness;

[0076] b2. Take the last i items of the chaotic sequences A1 and A2, perform i scrambling operations on the plaintext image P, and obtain the scrambled image P1, where the scrambling is performed using the Arnold transform, and the required parameters are the values ​​of the corresponding positions in the two chaotic sequences calculated using the Hénon mapping according to the number of rounds;

[0077] At this time, by adopting chaotic mapping encryption, the non-periodic, non-convergent and irregular motion characteristics of chaotic systems in deterministic systems can be used to greatly improve the ability of encryption algorithms to resist analytical attacks and reverse cracking;

[0078] At the same time, these characteristics of chaotic systems make the encryption process highly complex and unpredictable, thereby improving the security of image encryption algorithms. Even if an attacker has powerful computing resources, it is difficult to crack the encrypted data through traditional methods;

[0079] Furthermore, in order to adapt to the situation of different aspect ratios of images in practical applications, the scrambling algorithm needs to be improved. The improved Arnold scrambling iteration operation uses a window sliding method to perform Arnold scrambling operations on the image matrix areas in the window respectively, so as to solve the problems that the original algorithm can only scramble images with equal length and width, and the transformation has periodicity and insufficient key space. Through multiple rounds of iterations, a good scrambling effect is achieved. The specific operation steps of improving the Arnold scrambling operation here include:

[0080] c1. Before the operation, determine the block size k and step size s of the sliding window. The block size k is the minimum value of the image length and width, and the step size s is the greatest common divisor of the image length and width. Then, perform an Arnold scrambling operation on the original image matrix from the upper left with a size of k×k.

[0081] c2. Slide rightward or downward by a distance s, and perform another Arnold scrambling operation within the new k×k size until all pixels of the original image have been scrambled at least once. This completes a round of scrambling, and then transposes the image matrix.

[0082] Step S6. According to the characteristics of the Logistics map and the Tent map, the scrambled image is XOR-diffused using the initial values ​​obtained by preprocessing to obtain encrypted image data. At this time, the image after scrambling and two diffusions can no longer express the information contained in the original image, nor can it extract features similar to the original image. This step specifically includes:

[0083] d1. Bring the initial values ​​of the parameters {p3,u3} and {p4,u4} after preprocessing into the one-dimensional chaotic mapping of the second and third layers, and calculate the rounds for at least the length l of the image data to obtain two chaotic sequences A3 and A4 with a length not less than l;

[0084] d2. Take the last item of chaotic sequence A3, use image diffusion algorithm on the scrambled image P1, and get the first diffusion image P2;

[0085] d3. Take the last item of chaotic sequence A4, use the image diffusion algorithm on the image P3 after the first diffusion, and obtain the encrypted image P3;

[0086] Step S7. For other data element information of the DICOM file, select the extracted feature sequence according to the rules, perform symmetric encryption with key as the key, and obtain the corresponding key that can be used for symmetric encryption;

[0087] Step S8. For all data element information except the image, use the key to complete symmetric encryption to obtain an encrypted data sequence;

[0088] At this time, by implementing key-based symmetric encryption technology on the non-image data metadata, it can protect the relevant information from being illegally obtained, thereby ensuring the secure transmission and storage of the entire DICOM document content;

[0089] Step S9: The encrypted image data and the encrypted data sequence are reassembled into a file according to the DICOM standard file format to obtain a DICOM encrypted file that complies with the file specification but has encrypted content.

[0090] In the above encryption methods, it is generally believed that the encryption algorithm is public, so the security of data encryption mainly depends on the difficulty of reverse cracking the parameters in each encryption process.

[0091] At the same time, since the generation of the key is closely related to the original file, and the chaotic sequence generated by the chaotic map has strong resistance to cracking due to its randomness and unpredictability, the above-mentioned DICOM file encryption method introduces chaotic mapping, builds a chaotic encryption system, and combines chaotic mapping with image replacement and diffusion algorithms to utilize the randomness and unpredictability of chaos, thereby greatly improving the encryption algorithm's ability to resist analysis attacks and reverse cracking, and improving the security of the image encryption algorithm.

[0092] Therefore, by using the improved Arnold scrambling operation to process the image and combining it with three-layer chaotic mapping (Hénon, Logistic, Tent) for image diffusion, the original image structure can be completely disrupted. The improved Arnold scrambling operation ensures that each pixel in the image is scrambled at least once by setting the sliding window and step size. The three-layer chaotic mapping further increases the randomness and complexity of the image data, thereby maintaining a high degree of confidentiality of the data and achieving effective protection of sensitive images.

[0093] Based on the above embodiment, the DICOM encrypted file also has a decryption step, and the specific decryption algorithm used is essentially the inverse operation of the encryption algorithm:

[0094] L1. Obtain the feature sequence of the file through a secure private channel, and build a three-layer chaotic system according to the same operation as the encryption method to calculate and obtain the chaotic sequences at each level;

[0095] L2. After the encrypted image is subjected to the reverse diffusion operation of the third and second chaotic sequences respectively, it is subjected to the reverse scrambling algorithm of the two chaotic sequences obtained by the first chaotic mapping calculation to obtain the restored image data;

[0096] L3. Perform rule selection on the feature sequence, use the obtained key to symmetrically decrypt the data element sequence, restore the original data element information, and combine the restored image data into a decrypted DICOM file.

[0097] In one embodiment, if Figure 3 As shown, the decryption method specifically includes the following steps:

[0098] Step S201: Read the encrypted DICOM file, obtain the encrypted image data and other encrypted data elements as the ciphertext image P3 and the encrypted sequence D1 input;

[0099] Step S202: Obtaining a feature sequence from the encryption party through a private channel;

[0100] Step S203: As in the encryption step S103, preprocess the feature sequence to form four sets of parameters;

[0101] Step S204: Same as the encryption step S107, obtaining two chaotic sequences A3 and A4 whose lengths are not less than the image data length l;

[0102] Step S205: Take the last item of chaotic sequence A4, perform a reverse diffusion operation on the ciphertext image P3, and obtain the intermediate image P2;

[0103] Step S206: Take the last term of the chaotic sequence A3, perform a reverse diffusion operation on the intermediate image P2, and obtain the scrambled image P1;

[0104] Step S207: Same as the encryption step S105, obtaining two chaotic sequences A1 and A2 whose lengths are not less than the polling number i of the scrambling algorithm;

[0105] Step S208: Take the last i items of the chaotic sequences A1 and A2, and perform i times of inverse scrambling algorithm operation on the scrambled image P1 to obtain the plaintext image P;

[0106] Step S209: Similar to step S110, the acquired feature sequence is processed into a key that can be used for symmetric decryption through rule selection;

[0107] Step S210: Same as step S111, the encrypted sequence D1 is symmetrically decrypted using key as the key to obtain the decrypted sequence D1;

[0108] Step S211: Combine the decrypted image P and sequence D according to the DICOM standard to obtain the decrypted original file.

[0109] Step S212: Extract features from the decrypted original file through the SHA-512 algorithm, compare the extracted feature values ​​with the acquired feature values, and verify file consistency. At this time, by first performing SHA-512 feature extraction on the input DICOM file information, a unique feature sequence can be generated, thereby ensuring that each file has its own unique encryption basis, thereby enhancing the irreversibility and cracking difficulty of the encryption algorithm, thereby improving the security of the overall system. That is, by introducing a file integrity verification mechanism, the file feature values ​​are verified again using SHA-512 after decryption, which can detect whether the file has been tampered with or damaged, thereby ensuring that the decrypted data is authentic and reliable.

[0110] In addition, it should be noted that after the decrypted DICOM file is obtained, it is necessary to prove that the file restoration is valid. The specific proof steps include: using the SHA-512 algorithm to extract features from the obtained DICOM file, and comparing the obtained feature sequence with the feature sequence obtained from the private channel. If they are completely consistent, the restoration is proven to be valid.

[0111] The above decryption method is essentially the inverse operation of the encryption method, but after restoration, the validity of the file can be verified based on the feature sequence comparison, and whether the encrypted file has been tampered with can be identified. Specifically: after obtaining the decrypted image, feature extraction is performed on it, and the calculated feature value is compared with the feature value received by the private channel. The complete consistency proves that the encrypted file transmitted this time is complete and has not been tampered with. That is, by verifying the integrity of the decrypted file, the consistency of the file data before and after encryption can be ensured.

[0112] In summary, during the execution of the encryption method for non-destructive testing DICOM image files, it is assumed that both the encryption and decryption parties have a reliable private channel to transmit the feature sequence, which can ensure that the feature sequence used for decryption is accurate to achieve image integrity verification.

[0113] On the other hand, Figure 4 As shown, the present invention also discloses an encryption system for non-destructive testing DICOM image files, which is used to execute any of the above encryption methods for non-destructive testing DICOM image files, including:

[0114] Data transmission module, used for receiving or sending DICOM original image files, DICOM encrypted files and keys corresponding to the encrypted files;

[0115] DICOM image reading module, used to read DICOM files to obtain image data information and other data element information, and extract unique feature sequences;

[0116] A chaotic mapping encryption module is used to perform chaotic mapping encryption on the image data information according to a three-layer chaotic mapping function based on a feature sequence to obtain encrypted image data;

[0117] The symmetric encryption module is used to select other data element information based on the feature sequence and obtain the encrypted data sequence and the corresponding key after symmetric encryption;

[0118] A file combination module, used for recombining the encrypted image data and the encrypted data sequence to form a DICOM encrypted file;

[0119] The reverse decryption module is used to use the key to perform a decryption operation on the DICOM encrypted file according to the inverse operation of the encryption step to obtain the decrypted DICOM original image file.

[0120] On the other hand, the present invention further discloses a computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor executes the steps of the above method.

[0121] On the other hand, the present invention further discloses a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the above method.

[0122] In another embodiment provided by the present application, a computer program product including instructions is also provided, which, when executed on a computer, enables the computer to execute any encryption method for a non-destructive testing DICOM image file in the above embodiments.

[0123] It is understandable that the system provided by the embodiment of the present invention corresponds to the method provided by the embodiment of the present invention, and the explanation, examples and beneficial effects of the relevant contents can refer to the corresponding parts in the above method.

[0124] The embodiment of the present application also provides an electronic device, including a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other through the communication bus.

[0125] Memory, used to store computer programs;

[0126] The processor is used to implement the encryption method of the non-destructive testing DICOM image file when executing the program stored in the memory.

[0127] The communication bus mentioned in the above electronic device can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The communication bus can be divided into an address bus, a data bus, a control bus, etc.

[0128] The communication interface is used for communication between the above electronic device and other devices.

[0129] The memory may include a random access memory (RAM) or a non-volatile memory (NVM), such as at least one disk memory. Optionally, the memory may also be at least one storage device located away from the aforementioned processor.

[0130] The above-mentioned processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, and discrete hardware components.

[0131] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium, (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive Solid State Disk (SSD)), etc.

[0132] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

[0133] In addition, it should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0134] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or schemes that A and B meet at the same time. In addition, in the embodiments of the present invention, "multiple" refers to more than two. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field 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 invention.

Claims

1. A method for encrypting DICOM image files for non-destructive testing, characterized in that: The specific steps are as follows: Step S1. Read the DICOM file, obtain image data information and other data element information, and input them as plain text image P and data sequence D; Step S2. Extract the input information through the SHA-512 algorithm to obtain a unique feature sequence; Step S3. preprocessing the feature sequence into the initial value required for the three-layer chaotic mapping; Step S4. constructing a chaotic mapping function in a three-layer manner, wherein the first layer is a Hénon two-dimensional chaotic mapping, the second layer is a Logistic one-dimensional chaotic mapping, and the third layer is a Tent one-dimensional chaotic mapping; Step S5. The initial value obtained by preprocessing is put into Hénon mapping, and the chaotic mapping is polled and calculated for the same round according to the length of the image data and other metadata, and finally a chaotic sequence of equal length or slightly longer than the image data is obtained, and the original image is subjected to multiple rounds of improved Arnold scrambling operations according to the chaotic sequence; Step S6. According to the characteristics of the Logistics map and the Tent map, the scrambled images are XOR diffused using the initial values ​​obtained by preprocessing to obtain encrypted image data; Step S7. For other data element information of the DICOM file, select the extracted feature sequence according to the rules, perform symmetric encryption with key as the key, and obtain the corresponding key that can be used for symmetric encryption; Step S8. For all data element information except the image, use the key to complete symmetric encryption to obtain an encrypted data sequence; Step S9: The encrypted image data and the encrypted data sequence are reassembled into a file according to the DICOM standard file format to obtain a DICOM encrypted file that complies with the file specification but has encrypted content.

2. The encryption method for nondestructive testing DICOM image files according to claim 1, characterized in that: The specific operation steps in the S3 step include: a1. Preprocess the feature sequence into four sets of parameters {p1,u1}, {p2,u2}, {p3,u3}, {p4,u4}; a2. The parameters {p1,u1} and {p2,u2} are processed as follows to obtain initial values, so that these initial values ​​can guide the subsequent items obtained by the mapping function to have chaotic characteristics: a3. The parameters {p3,u3} and {p4,u4} are processed as follows to obtain initial values, so that these initial values ​​can guide the subsequent items of the mapping function to have chaotic characteristics; 3. The encryption method for nondestructive testing DICOM image files according to claim 2, characterized in that: The specific operation steps in step S5 include: b1. Bring the pre-processed initial values ​​of the parameters {p3, u3} and {p4, u4} into the first layer of two-dimensional chaotic mapping, calculate the rounds at least equal to the polling number i of the scrambling algorithm, and obtain two chaotic sequences A1 and A2 with a length not less than i; b2. Take the last i items of the chaotic sequences A1 and A2, perform i improved Arnold scrambling operations on the plaintext image P, and obtain the scrambled image P1.

4. The encryption method for nondestructive testing DICOM image files according to claim 1, characterized in that: The specific operation steps of improving the Arnold scrambling operation in step S5 include: c1. Before the operation, determine the block size k and step size s of the sliding window. The block size k is the minimum value of the image length and width, and the step size s is the greatest common divisor of the image length and width. Then, perform an Arnold scrambling operation on the original image matrix from the upper left with a size of k×k. c2. Slide rightward or downward by a distance s and perform another Arnold scrambling operation within the new k×k size until all pixels of the original image have been scrambled at least once, and then a round of scrambling is completed.

5. The encryption method for nondestructive testing DICOM image files according to claim 1, characterized in that: The specific operation steps in step S6 include: d1. Bring the initial values ​​of the parameters {p3,u3} and {p4,u4} after preprocessing into the one-dimensional chaotic mapping of the second and third layers, and calculate the rounds for at least the length l of the image data to obtain two chaotic sequences A3 and A4 with a length not less than l; d2. Take the last item of chaotic sequence A3, use image diffusion algorithm on the scrambled image P1, and get the first diffusion image P2; d3. Take the last item of chaotic sequence A4, use the image diffusion algorithm on the image P3 after the first diffusion, and obtain the encrypted image P3.

6. The encryption method for nondestructive testing DICOM image files according to claim 1, characterized in that: In step S9, the DICOM encrypted file has the following decryption steps: L1. Obtain the feature sequence of the file through a secure private channel, and build a three-layer chaotic system according to the same operation as the encryption method to calculate and obtain the chaotic sequences at each level; L2. After the encrypted image is subjected to the reverse diffusion operation of the third and second chaotic sequences respectively, it is subjected to the reverse scrambling algorithm of the two chaotic sequences obtained by the first chaotic mapping calculation to obtain the restored image data; L3. Perform rule selection on the feature sequence, use the obtained key to symmetrically decrypt the data element sequence, restore the original data element information, and combine the restored image data into a decrypted DICOM file.

7. The encryption method for nondestructive testing DICOM image files according to claim 6, characterized in that: After obtaining the decrypted DICOM file in the L3 step, it is also necessary to prove that the file restoration is valid. The specific proof steps include: extracting features from the obtained DICOM file using the SHA-512 algorithm, and comparing the obtained feature sequence with the feature sequence obtained from the private channel. If they are completely consistent, the restoration is proven to be valid.

8. A non-destructive testing DICOM image file encryption system, used to execute the non-destructive testing DICOM image file encryption method according to any one of claims 1 to 7, characterized in that: include: Data transmission module, used for receiving or sending DICOM original image files, DICOM encrypted files and keys corresponding to the encrypted files; DICOM image reading module, used to read DICOM files to obtain image data information and other data element information, and extract unique feature sequences; A chaotic mapping encryption module is used to perform chaotic mapping encryption on the image data information according to a three-layer chaotic mapping function based on a feature sequence to obtain encrypted image data; The symmetric encryption module is used to select other data element information based on the feature sequence and obtain the encrypted data sequence and the corresponding key after symmetric encryption; A file combination module, used for recombining the encrypted image data and the encrypted data sequence to form a DICOM encrypted file; The reverse decryption module is used to use the key to perform a decryption operation on the DICOM encrypted file according to the inverse operation of the encryption step to obtain the decrypted DICOM original image file.

9. A computer-readable storage medium, characterized in that: A computer program is stored, and when the computer program is executed by a processor, the processor is caused to perform the steps of the method according to any one of claims 1 to 7.

10. A computer device, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the method according to any one of claims 1 to 7.

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