A DICOM file-based security processing and transmission method, client and server

Abstract

The application discloses a kind of based on the safe processing and transmission method of DICOM file, client and server, comprising: obtaining DICOM file, the DICOM file includes metadata info and image data img;The metadata info is de-sensitized and is handled, and sensitive data is obtained;The sensitive data is encrypted, and the sensitive data after encryption is written in image data img;The metadata info after de-sensitization processing and the image data img of writing encrypted sensitive data are generated new DICOM file according to preset format, and the new DICOM file is sent to server.The application retains the IMG data and META data of original file, and is stored in somewhere of file itself by safe encryption means, and processed DICOM cannot view METADATA and other private information by ordinary method, but using corresponding authorized reverse method can still analyze and view relevant information.Therefore, the method retains META information under encryption mode, while patient privacy is maximally protected.

Description

Technical Field

[0001] This invention relates to the fields of medical artificial intelligence and encryption / decryption and secure transmission of medical images, specifically to a secure processing and transmission method, client, and server based on DICOM files. Background Technology

[0002] With the rapid development of artificial intelligence, the application of AI in the medical industry has also entered a stage of rapid development, with medical imaging-related AI applications being a major research direction. The DICOM protocol and standard are universal standards for exchanging and managing medical imaging data, used for communication between information systems and devices. Patient examination images acquired by hospital medical equipment are DICOM files. Because these files store information including the patient's name, gender, age, address, and past medical history, leakage of this information during the use and transmission of DICOM files could infringe on patient privacy rights. Therefore, there is a need to research an efficient method and system for the secure processing and network transmission of DICOM files. Summary of the Invention

[0003] The purpose of this invention is to provide a secure processing and transmission method, client, and server based on DICOM files. This method can retain the IMG and META data of the original file and store them securely and encrypted within a specific location within the file itself. The processed DICOM file cannot be viewed using ordinary methods to access its META data and other private information, but the relevant information can still be parsed and viewed using the corresponding authorized reverse method. Therefore, this method preserves META information while maximizing patient privacy.

[0004] A secure processing and transmission method based on DICOM files specifically includes the following steps:

[0005] Obtain the DICOM file, which includes metadata (info) and image data (img).

[0006] The metadata info is anonymized to obtain sensitive data;

[0007] The sensitive data is encrypted, and the encrypted sensitive data is written into the image data (img).

[0008] The de-identified metadata (info) and the image data (img) containing encrypted sensitive data are used to generate a new DICOM file according to a preset format, and the new DICOM file is sent to the server.

[0009] Furthermore, the server performs a restoration process based on the new DICOM file to generate a restored DICOM file.

[0010] Furthermore, the desensitization process specifically includes the following steps:

[0011] Sensitive data is extracted from the metadata info according to the sensitive data identification model, and sensitive data is deleted from the metadata to generate new metadata new-info. The metadata info is divided into sensitive data and non-sensitive data. Non-sensitive data refers to: new metadata new-info.

[0012] Furthermore, the sensitive data is encrypted, and the encrypted sensitive data is written into the image data (img). This specifically includes the following steps:

[0013] Encrypt sensitive data to obtain the confidential information stream encrypt-info;

[0014] Perform discrete wavelet transform on the image data img to obtain LL1 component, LH1 component, HL1 component, and HH1 component;

[0015] The confidential information stream encrypt-info is embedded in the LL1 component to generate the LL1-1 component;

[0016] The LL1-1 component, along with the LH1, HL1, and HH1 components, undergoes inverse discrete wavelet transform to reconstruct and generate new image data new-img.

[0017] The new DICOM file is generated according to a preset format based on the new image data new-img and the new metadata new-info.

[0018] Furthermore, the server restoration process specifically includes the following steps:

[0019] New DICOM received;

[0020] Based on the new image data new-img, a discrete wavelet transform is performed to obtain the LL1-1 component, LH1 component, HL1 component, and HH1 component.

[0021] Based on the LL1-1 component, confidential information is extracted to obtain the confidential information stream encrypt-info and the LL1-0 component with the confidential information stream removed;

[0022] The confidential information stream encrypt-info is decrypted to generate decrypted sensitive data. The decrypted sensitive data is then merged with the new metadata new-info to form metadata old-info.

[0023] The image data old-img is reconstructed by performing inverse discrete wavelet transform based on the LL1-0 component, LH1 component, HL1 component, and HH1 component.

[0024] The metadata old-info and image data old-img are combined to generate an OLD-DICOM file according to a preset format, and the OLD-DICOM file is returned to the client.

[0025] Further, the confidential information stream encrypt-info is embedded in the LL1 component to generate the LL1-1 component, specifically including the following steps:

[0026] The number of bytes m in the encrypted computer information stream encrypt-info and the maximum number of bytes n that the LL1 component can hide, where n is 1 / 8 of the total number of bytes in the LL1 component;

[0027] Compare the sizes of m and n;

[0028] If m <= n, then read the data of m bytes of LL1 component in sequence and put them into the predefined set A;

[0029] Read one bit of the confidential information stream encrypt-info in sequence, and replace the lowest bit of the byte in set A with the one bit of the confidential information stream encrypt-info in sequence until the confidential information stream encrypt-info is completely hidden.

[0030] Furthermore, the sensitive data identification model specifically includes the following steps:

[0031] Load the configuration file and read the preset sensitive information names and TAG values;

[0032] The sensitive data is obtained by searching the metadata info based on the preset sensitive information name and TAG value.

[0033] A client for secure processing and transmission of DICOM files, comprising:

[0034] The client receives a DICOM file uploaded by the medical device, the DICOM file including metadata Info and image data Img;

[0035] The client extracts sensitive data from the metadata, encrypts it to obtain a confidential information stream encrypt-info, and deletes sensitive data from the metadata to generate new metadata new-info.

[0036] The client performs discrete wavelet transform on the image data to obtain LL1, LH1, HL1, and HH1 components;

[0037] The client determines the target component based on the LL1 component, LH1 component, HL1 component, and HH1 component;

[0038] The client embeds the confidential information stream encrypt-info into the target component;

[0039] The client performs inverse discrete wavelet transform on the target component and the other three components to reconstruct and generate new image data new-img;

[0040] The client generates a new DICOM file according to a preset format based on the new image data (new-img) and the new metadata (new-info), and sends the new DICOM file to the server.

[0041] A client for secure processing and transmission of DICOM files, comprising:

[0042] The server receives a new DICOM, which includes new image data new-img and new metadata new-info;

[0043] The server performs discrete wavelet transform on the new image data new-img to obtain the target component and the other three components.

[0044] The server extracts the confidential information stream encrypt-info based on the target component, and performs inverse discrete wavelet transform on the target component (after deleting the confidential information stream encrypt-info) and the other three components to reconstruct and generate image data old-img.

[0045] The server decrypts the confidential information stream encrypt-info, generates decrypted data, and merges the decrypted data with the new metadata new-info into metadata old-info;

[0046] The server generates an OLD-DICOM file from the metadata old-info and the image data old-img according to a preset format, and returns the OLD-DICOM file to the client.

[0047] In existing technology, when a host sends a data frame, it uses a hash function to generate a message digest from the data text, and then encrypts the digest using a private key generated from pseudo-random numbers stored internally by the host. This encrypted digest is sent to the receiver as a digital signature along with the message. The receiver first calculates the message digest from the received original message using the same hash function as the host, and then uses the public key to decrypt the digital signature attached to the message. If the two digests are the same, the receiver can confirm that the data frame originated from the sender's host.

[0048] In this application, based on the characteristics of DICOM files including metadata (info) and image data (img), and the metadata (info) including sensitive and non-sensitive data, a sensitive data identification model is used to extract sensitive data for confidentiality, obtaining a confidential information stream (encrypt-info). The image data (img) is then subjected to discrete wavelet transform, hiding the confidential information stream (encrypt-info) in one of the components after the discrete wavelet transform, thereby generating a new DICOM file and sending it to the server. This preserves the data integrity of the original DICOM file while ensuring the security of the DICOM file transmission process.

[0049] The beneficial effects of this invention are as follows:

[0050] 1. This application reads sensitive data from the METADATA data in the DICOM file, uses a dedicated software dongle interface to read the software encryption key pair to encrypt the sensitive data, writes the encrypted sensitive data into the DICOM image data, erases the sensitive data from the original METADATA data in the DICOM file, and initiates the transmission client to transmit the new DICOM file through an SSL encrypted channel; the server receives and stores the new DICOM file; it reads the encrypted sensitive data stored in the image data, calls the dedicated software dongle interface to obtain the dedicated key to decrypt the sensitive data, thereby restoring the METADATA data, and returns it to the viewing client along with the reconstructed image data through the WADO service. The viewing client can then normally browse and process the DICOM image and metadata. This method preserves METADATA information while maximizing the protection of patient privacy.

[0051] 2. To ensure key security, this system uses a software dongle to store the key and retrieves it through a dedicated API interface, thus improving both convenience and security. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of the secure processing and secure transmission process of DICOM files according to the present invention;

[0053] Figure 2This is a schematic diagram of the DICOM file receiving and secure access viewing process of the present invention;

[0054] Figure 3 This is a schematic diagram of the client structure of the present invention;

[0055] Figure 4 This is a schematic diagram of the server-side structure of the present invention;

[0056] Figure 5 This is a schematic diagram of the new DICOM file generation process of the present invention; Detailed Implementation

[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention.

[0059] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0060] Furthermore, for clarity and brevity, descriptions of well-known structures, functions, and configurations may have been omitted. Those skilled in the art will recognize that various changes and modifications can be made to the examples described herein without departing from the spirit and scope of this disclosure.

[0061] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0062] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0063] Example 1

[0064] A method for securely processing medical image DICOM files, the main steps of which include:

[0065] Step 1: Using the hospital's historical image data as a reference set, set the range of sensitive data areas through free configuration, and form basically stable sensitive identification parameters;

[0066] Step 2: For the medical images to be processed, analyze and identify the sensitive data that needs to be processed;

[0067] Step 3: Read the DICOM image data and extract the METADATA metadata and IMG image data respectively;

[0068] Step 4: Based on the sensitive data identification model, list the confidentiality configuration file attributes and specify the confidentiality attributes in the information structure;

[0069] Step 5: Activate the software dongle, obtain the encryption key and encrypt the confidentiality attributes, and convert them into an encrypted binary stream;

[0070] Step 6: Perform wavelet transform on the image data IMG to obtain the coefficients LL1, LH1, HL1 and HH1;

[0071] Step 7: Determine the LSB as the embedding location for the wavelet transform LL subband;

[0072] Step 8: Determine the dual-mode image data to be used for the embedding location;

[0073] Step 9: Embed the encrypted binary stream into the specified embedding location;

[0074] Step 10: Remove the confidentiality attribute from the information structure;

[0075] Step 11: Reconstruct the image data IMG by applying inverse discrete wavelet transform;

[0076] Step 12: Write the modified image data (IMG) and information structure into a new DICOM file;

[0077] Step 13: Start the client program and send the processed new DICOM file to the server through an SSL secure channel;

[0078] Step 14: The server program receives and stores the DICOM file;

[0079] The main steps for restoring data from a securely processed DICOM file include:

[0080] Step 1: Read the image data (IMG) from the new DICOM file for processing;

[0081] Step 2: Specify the confidentiality attributes in the information structure according to the confidentiality configuration file attributes listed in the sensitive data identification model;

[0082] Step 3: Apply wavelet transform to the image data IMG to obtain the LSB, LH1, HL1 and HH1 coefficients;

[0083] Step 4: Determine the dual-mode image data LSB-img used in the embedding process from the LL sub-band of the wavelet transform, and extract the hidden data;

[0084] Step 5: Activate the software dongle and use the encryption key provided by the software dongle to decrypt the extracted hidden data to recover the METADATA value;

[0085] Step 6: Rewrite the extracted values ​​into the META-TAG structure;

[0086] Step 7: The decrypted DICOM data and image are returned to the client.

[0087] Another object of the present invention is to provide a system for secure processing and transmission of DICOM data, which mainly includes:

[0088] The software dongle and security key module requires a key because the related functions involve reversible encryption. The most secure and reliable form of key is the dongle. Therefore, this design uses a lower-cost software dongle and obtains the security key stored in the software dongle through an API.

[0089] The medical image reading and parsing module can obtain DICOM data to be processed in the database or queue, and parse out the META and IMG parts;

[0090] The medical image file sensitive information search and processing module can identify sensitive information in DICOM files. The further sensitive information search and identification process involves: 1. Loading the configuration file and reading the names and TAG values ​​of the sensitive information to be processed; 2. Searching for and confirming the corresponding sensitive information in the METADATA metadata, including patient information, medical records, hospital information, address information, etc. The following table lists some of the sensitive information:

[0091] Table 1 Patient Information

[0092]

[0093] Table 2. Equipment and Hospital Related Information

[0094] property Tag illustrate Modality 0008,0060 Inspection type Manufacture 0008,0070 Manufacturer Institution name 0008,0080 Organization Name Institution address 0008,0080 Organization Address Station name 0008,1010 Site Name Operator's name 0008,1070 Operator

[0095] Table 3 Inspection Information

[0096]

[0097]

[0098] Table 4 Image Information

[0099]

[0100]

[0101] As attached Figure 1 As shown, the process of secure desensitization and secure transmission of DICOM files is described in detail. The process steps have been explained above, and this section mainly focuses on the core implementation steps.

[0102] DICOM data acquisition: The system involved in this invention needs to obtain DICOM data. This system establishes a DICOM-SCP service to receive DICOM data pushes.

[0103] Software dongle and key: This system involves data encryption and decryption, and the security of the key is of paramount importance. This system uses a software dongle to store the key and obtains it through a dedicated API interface, which ensures both convenience and security.

[0104] Encrypted network transmission: The SSL Secure Sockets Protocol ensures network transport layer security. The file transfer client and server in this system use the HTTPS security protocol and are transmitted over a dedicated network.

[0105] File integrity verification: A single STUDY of medical image files contains hundreds of DICOM files. To ensure data integrity, a file integrity verification mechanism is needed between the client and the server. If a timeout or anomaly occurs during transmission, a verification and retransmission mechanism is used to ensure data security and integrity.

[0106] As attached Figure 2 As shown, the process of receiving and securely calling DICOM to view information is described, ensuring that sensitive META information cannot be viewed without authorization, while complete information can be viewed when authorized.

[0107] Encrypted information recovery: After the encrypted information is extracted using a specific algorithm, it needs to be decrypted using a specified key. This key is still obtained in the form of a software dongle. The server installs the dongle and obtains the authorized key, which enables the encrypted information to be decrypted and recovered normally.

[0108] Encryption / decryption algorithm: Any commercial or open-source reversible encryption / decryption algorithm can be used. This invention does not specify a particular single algorithm; any efficient reversible encryption algorithm that meets the conditions can be used.

[0109] WADO Service: When an authorized client accesses the WADO service, the decrypted sensitive META information will be encoded together with the IMG information and returned to the client so that the client can view the image and META information normally.

[0110] Security Guarantee: When unauthorized clients access DICOM files that have been securely processed by this system, they will only be able to read image files with unclear meanings, which cannot be used for research purposes, thus reliably protecting sensitive privacy data.

[0111] For example:

[0112] 1. Divide the DICOM data into two parts:

[0113] img: Image data, i.e., pixel data;

[0114] info: metadata, i.e., tag data;

[0115] 2. Based on the definition, identify the confidential information in Info (select more than 10 items to be protected from over 1000 options).

[0116] 3. Encrypt the confidential information in info using a two-way encryption algorithm with a key, and convert it into a confidential information stream encrypt-info;

[0117] 4. Erase the confidential information and generate a new "new-info" (info that lacks the confidential information);

[0118] 5. Use Integer Wavelet Transform (IWT, a special type of Discrete Wavelet Transform DWT) to transform the image data img to obtain LL1, LH1, HL1, HH1;

[0119] The LSBs (Least Significant Bit Substitution) algorithm is used to replace the encrypted confidential information stream encrypt-info into LL1, resulting in LL1-1;

[0120] LSB stands for least significant bit, a steganography method that modifies stored information based on the least significant bit of an image. Image pixels are generally composed of the three primary colors RGB (red, green, and blue), each color occupying 8 bits with values ​​from 0x00 to 0xFF (decimal 0 to 255). (Data starting with 0x represents hexadecimal, resulting in 256 possible values, for a total of 256 cubed colors, or 16,777,216 colors.

[0121] The human eye can only distinguish about 10 million different colors, and there are many subtle variations that the human eye cannot perceive. LSB steganography stores information by modifying the least significant bit (LSB) of the RGB color components, and the human eye cannot perceive the changes before and after.

[0122] Each pixel can carry 3 bytes of information, while a typical DICOM image pixel is 16 bits, with 12 bits being effectively used. Therefore, replacement does not affect important information in the image data.

[0123] 6. Finally, the four data sets LL1-1, LH1, HL1, and HH1 are reconstructed into a new image data set new-img using the inverse integer wavelet transform (IIWT).

[0124] 7. Combine new-info and new-img according to the DICOM standard and write them into a DICOM file to form new-dicom. This file is a new file in which the sensitive information that needs to be protected has been encrypted and integrated into the same file body.

[0125] Restoration process:

[0126] 1. Read the contents of the new-dicom file and divide them into two parts: new-info and new-img;

[0127] 2. Use integer wavelet transform to divide the new-img into LL1-1, LH1, HL1, and HH1;

[0128] 3. Determine the steganographic confidential information stream encrypt-info from LL1-1 using the LSBs algorithm; remove the data hiding the confidential information stream and store it as LL1-0;

[0129] 4. Reconstruct the four data sets LL1-0, LH1, HL1, and HH1 into an old-img file using the inverse integer wavelet transform (IIWT);

[0130] 5. Use the key to decrypt the confidential information stream encrypt-info, and merge it with info to generate old-info (complete info);

[0131] 6. Restore old-img and old-info to old-dicom files.

[0132] Example 2: A computer-readable storage medium storing a computer program thereon, which, when executed by a processor, enables the implementation of the aforementioned secure processing and transmission method based on DICOM files.

[0133] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Based on the technical essence of the present invention, any simple modifications, equivalent substitutions, and improvements made to the above embodiments within the spirit and principles of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for secure processing and transmission of DICOM files, characterized in that, Specifically comprising the following steps: Obtaining a DICOM file, wherein the DICOM file comprises metadata info and image data img; Performing desensitization processing on the metadata info to obtain sensitive data; The desensitization processing specifically comprises the following steps: Extracting sensitive data from the metadata info according to a sensitive data identification model, and generating new metadata new-info by deleting the sensitive data from the metadata info, wherein the metadata info is divided into sensitive data and non-sensitive data, and the non-sensitive data refers to the new metadata new-info; Encrypting the sensitive data, and writing the encrypted sensitive data into the image data img, specifically comprising the following steps: Encrypting the sensitive data to obtain a confidential information stream encrypt-info; Performing discrete wavelet transform on the image data img to obtain LL1 component, LH1 component, HL1 component and HH1 component; Embedding the confidential information stream encrypt-info in the LL1 component to generate LL1-1 component; Using LSB algorithm to replace the encrypted confidential information stream encrypt-info into LL1, and the replacement is LL1-1; Performing inverse discrete wavelet transform on the LL1-1 component, LH1 component, HL1 component and HH1 component to reconstruct and generate new image data new-img; Generating a new DICOM file according to the new image data new-img and the new metadata new-info in a preset format, and sending the new DICOM file to a server.

2. The method for secure processing and transmission of DICOM files according to claim 1, wherein, The server performs restoration processing on the new DICOM file to generate a restored DICOM file.

3. The method of claim 2, wherein the DICOM file is encrypted and the encrypted DICOM file is transmitted to the DICOM server. The restoration processing of the server specifically comprises the following steps: Receiving the new DICOM; Performing discrete wavelet transform on the new image data new-img to obtain LL1-1 component, LH1 component, HL1 component and HH1 component; Extracting confidential information according to the LL1-1 component to obtain a confidential information stream encrypt-info and LL1-0 component without the confidential information stream; Decrypting the confidential information stream encrypt-info to generate decrypted sensitive data, and merging the decrypted sensitive data with the new metadata new-info to obtain metadata old-info; Performing inverse discrete wavelet transform on the LL1-0 component, LH1 component, HL1 component and HH1 component to reconstruct and generate image data old-img; Generating an OLD-DICOM file according to the metadata old-info and the image data old-img in a preset format, and returning the OLD-DICOM file to a client.

4. The method for secure processing and transmission of DICOM files according to claim 3, wherein, Embedding the confidential information stream encrypt-info in the LL1 component to generate LL1-1 component, specifically comprising the following steps: The number of bytes m of the computer secret information stream encrypt-info and the maximum number of bytes n of the LL1 component that can be hidden, wherein n is 1 / 8 of the total number of bytes of the LL1 component; Comparing the sizes of m and n; If m<=n, reading the data of the LL1 component in m bytes in turn and putting them into a set A defined in advance; Reading the 1-bit bits of the secret information stream encrypt-info in turn and replacing the lowest 1-bit of the bytes in the set A with the 1-bit bits of the secret information stream encrypt-info in turn until the secret information stream encrypt-info is completely hidden.

5. The method for secure processing and transmission of DICOM files according to claim 1, wherein, The sensitive data extraction from the metadata info according to the sensitive data identification model specifically includes the following steps: Loading a configuration file to read preset sensitive information names and TAG values; Finding the sensitive data in the metadata info according to the preset sensitive information names and TAG values.

6. A client for secure processing and transmission of DICOM files, characterized in that It comprises: A memory having a computer program stored thereon, wherein the computer program is executed by a processor to implement the security processing and transmission method based on the DICOM file according to any one of claims 1-5.

7. A method for secure processing and transmission of DICOM files, characterized in that, It comprises: The server receives a new DICOM, which comprises new image data new-img and new metadata new-info; The server performs discrete wavelet transform on the new image data new-img to obtain a target component and three other components; The target component is an LL1-1 component, and the three components include an LH1 component, an HL1 component and an HH1 component; The server extracts a secret information stream encrypt-info determined by the LSB algorithm from the LL1-1 component according to the LL1-1 component, and stores the data without the hidden secret information stream as an LL1-0 component to obtain the secret information stream encrypt-info and the LL1-0 component without the secret information stream; The server performs inverse discrete wavelet transform on the LL1-0 component, the LH1 component, the HL1 component and the HH1 component to reconstruct the image data old-img; The server decrypts the secret information stream encrypt-info to generate decrypted data, and combines the decrypted data with the new metadata new-info to obtain metadata old-info; The server generates an OLD-DICOM file according to the metadata old-info and the image data old-img in a preset format, and returns the OLD-DICOM file to the client.

Images