A 4K Medical Image Content Interference Protection Method

Abstract

The present invention discloses a method for interfering with and protecting 4K medical image content. The present invention performs local conversion on the intra-slice data of medical image video frames in H264\H265 format for interference encryption. Eight bytes are respectively extracted from the 0%, 25%, 50%, and 75% positions of each slice data, and are respectively subjected to bitwise exclusive OR operations with 0xEF, 0xDE, 0xCD, and 0xBC in hexadecimal, and the obtained results are assigned back to the original 0%, 25%, 50%, and 75% positions of the slice data. The interference decryption uses the same process to restore the original data. The method designed by the present invention can realize the interference encryption and decryption of 4K medical image video pictures without damaging the H264\H265 frame structure and without affecting the subsequent encapsulation protocol's processing of H264\H265 data; the interference encryption and decryption process occupies less resources and has less impact on the real-time performance of 4K medical images.

Description

Technical Field

[0001] The present invention relates to the technical field of video image encryption and decryption, and particularly to a 4K medical image content interference protection method. Background Art

[0002] With the gradual popularization of remote consultations, the transmission and application of medical image video streams are increasing. Due to considerations of compatibility, the medical image video coding widely uses well-known standard coding formats such as H264\H265 and standard transmission protocols such as RTSP\RTMP\SRT. Moreover, the transmission needs to cross the Internet, and the video stream data of the standard protocol is extremely easy to be sniffed and intercepted. Especially, a lot of privacy information of medical staff and patients is involved in medical images. How to protect these data and privacy has become extremely necessary and urgent.

[0003] The existing protection methods on the market perform full encryption and decryption processing on video data, which has a certain amount of calculation. When the medical image is 4K (resolution: 3840×2160 or 4096×2160) and the bit rate is relatively high (≥80 megabits per second), the amount of calculation increases sharply. The encryption and decryption processes of the sender and the receiver will cause a great pressure on the occupation of local resources, and will also reduce the real-time performance of medical images, which will have a negative impact on remote consultations with high real-time requirements. Summary of the Invention

[0004] The purpose of the present invention is to provide a 4K medical image content interference protection method, which can realize the interference encryption and decryption of 4K medical image video pictures without destroying the H264\H265 frame structure and without affecting the subsequent encapsulation protocol's processing of H264\H265 data; the interference encryption and decryption process occupies less resources and has less impact on the real-time performance of 4K medical images.

[0005] To achieve the above functions, the present invention designs a 4K medical image content interference protection method. For a medical image video, the following steps S1 - S3 are executed to complete the encryption and decryption processing of the medical image video:

[0006] Step S1: At the sending end of the medical image video to be transmitted, for each video frame of the medical image video, find its slice data, divide the slice data into a preset number of parts, and perform local conversion on each divided part of the slice data respectively to complete the encryption processing of the medical image video to be transmitted;

[0007] Step S2: Transmit the encrypted medical image video through a standard transmission protocol;

[0008] Step S3: Receive the encrypted medical imaging video at the receiving end. For each video frame of the received medical imaging video, find its slice data, divide the slice data into a preset number of parts, and perform the same local conversion as in Step S1 on each divided part of the slice data to complete the decryption process of the received medical imaging video.

[0009] As a preferred technical solution of the present invention: The specific steps of Step S1 are as follows:

[0010] Step S1.1: Encode each video frame of the medical imaging video respectively to obtain encoded data. For the encoded data, find the network abstraction layer unit. If found, execute Step S1.2; otherwise, transmit the encoded data over the network through the standard transmission protocol.

[0011] Step S1.2: Find the header of the encoded data. If found, execute Step S1.3; otherwise, transmit the encoded data over the network through the standard transmission protocol.

[0012] Step S1.3: Find the slice data of the encoded data, divide the slice data into four equal parts, perform local conversion on each of the four divided parts of the slice data respectively, and assign the results of the local conversion to the original positions of the slice data respectively to complete the encryption of each video frame of the medical imaging video.

[0013] As a preferred technical solution of the present invention: The specific steps of Step S3 are as follows:

[0014] Step S3.1: Receive the encrypted medical imaging video at the receiving end and assemble the encoded data of each video frame; find the network abstraction layer unit. If found, execute Step S3.2; otherwise, perform conventional decoding and rendering on the encoded data.

[0015] Step S3.2: Find the header of the encoded data. If found, execute Step S3.3; otherwise, perform conventional decoding and rendering on the encoded data.

[0016] Step S3.3: Find the slice data of the encoded data, divide the slice data into four equal parts, perform local conversion on each of the four divided parts of the slice data respectively, and assign the results of the local conversion to the original positions of the slice data respectively to complete the decryption of each video frame of the medical imaging video.

[0017] As a preferred technical solution of the present invention: The method for performing local conversion on the four divided parts of the slice data is as follows:

[0018] Take the first eight bits of the first part of the slice data and perform an exclusive OR operation with the hexadecimal code 0xEF bit by bit, and assign the result of the exclusive OR operation to the first eight bits of the first part of the slice data.

[0019] Take the first eight bits of the second piece of data and perform an exclusive OR operation with the hexadecimal code 0xDE bit by bit, and assign the result of the exclusive OR operation to the first eight bits of the second piece of data;

[0020] Take the first eight bits of the third piece of data and perform an exclusive OR operation with the hexadecimal code 0xCD bit by bit, and assign the result of the exclusive OR operation to the first eight bits of the third piece of data;

[0021] Take the first eight bits of the fourth piece of data and perform an exclusive OR operation with the hexadecimal code 0xBC bit by bit, and assign the result of the exclusive OR operation to the first eight bits of the fourth piece of data.

[0022] As a preferred technical solution of the present invention: the medical image video format is the H264\H265 standard encoding format.

[0023] As a preferred technical solution of the present invention: the standard transmission protocol includes one or more of RTSP, RTMP, and SRT transmission protocols.

[0024] Beneficial effects: Compared with the prior art, the advantages of the present invention include:

[0025] When performing interference encryption and decryption on 4K color ultra-high-definition (resolution 4096×2160) medical images with a high bit rate (≥80 megabits per second), it is possible to complete the interference encryption and decryption of medical image content with less additional resources. When using a third-party player, the medical image data is intercepted during playback and displayed as mosaics, and the original medical image cannot be normally displayed; when using a player with interference decryption function for playback, the picture can be normally restored. Compared with the scheme without interference encryption and decryption, the additional delay after interference encryption and decryption is less than 10 milliseconds. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a flowchart of a method for protecting 4K medical image content from interference according to an embodiment of the present invention;

[0027] Figure 2 is a flowchart of the encryption process of a medical image video according to an embodiment of the present invention;

[0028] Figure 3 is a flowchart of the decryption process of a medical image video according to an embodiment of the present invention;

[0029] Figure 4 is an actual measurement effect diagram of a method for protecting 4K medical image content from interference according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0030] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0031] A 4K medical image content interference protection method provided by an embodiment of the present invention, for a medical image video, referring to Figure 1 , perform the following steps S1 - S3 to complete the encryption and decryption processing of the medical image video:

[0032] Step S1: At the sending end of the medical image video to be transmitted, for each video frame of the medical image video, find its slice data, divide the slice data into a preset number of parts, and perform local conversion on each divided part of the slice data respectively to complete the encryption processing of the medical image video to be transmitted; The flowchart of the encryption processing of the medical image video to be transmitted refers to Figure 2 .

[0033] The medical image video format is the H264\H265 standard encoding format. Both H264 and H265 belong to the video encoding standards, mainly used to compress video files to reduce file size and improve transmission speed.

[0034] The standard transmission protocol includes one or more of RTSP, RTMP, and SRT transmission protocols.

[0035] The specific steps of Step S1 are as follows:

[0036] Step S1.1: Encode each video frame of the medical image video respectively to obtain encoded data. For the encoded data, find the Network Abstract Layer Units (NALU). The network abstract layer unit is an important part of the H264\H265 standard encoding format, used to encapsulate video image data and related information, and transmit the encapsulated unit in the network; If the network abstract layer unit is found, then execute Step S1.2, otherwise transmit the encoded data through the standard transmission protocol;

[0037] Step S1.2: Find the Slice Header of the encoded data. The H264\H265 standard encoding format divides the video frame into multiple slices for compression. The slice header is an important part of the H264\H265 standard encoding format used to describe the structure of each slice; If the slice header is found, then execute Step S1.3, otherwise transmit the encoded data through the standard transmission protocol;

[0038] Step S1.3: Locate the slice data of the encoded data, divide the slice data into four equal parts, perform local conversions on the four divided slice data respectively, and assign the results of the local conversions to the original positions of the slice data to complete the encryption of each video frame of the medical imaging video.

[0039] Step S2: Transmit the encrypted medical imaging video through the standard transmission protocol;

[0040] Step S3: Receive the encrypted medical imaging video at the receiving end, locate the slice data for each video frame of the received medical imaging video, divide the slice data into a preset number of parts, and perform the same local conversions on each divided slice data as in Step S1 to complete the decryption process of the received medical imaging video; The flowchart of the decryption process of the received medical imaging video is referred to Figure 3 。

[0041] The specific steps of Step S3 are as follows:

[0042] Step S3.1: Receive the encrypted medical imaging video at the receiving end and assemble the encoded data of each video frame; Locate the network abstraction layer unit. If found, execute Step S3.2; otherwise, perform conventional decoding and rendering on the encoded data.

[0043] Step S3.2: Locate the header of the encoded data. If found, execute Step S3.3; otherwise, perform conventional decoding and rendering on the encoded data.

[0044] Step S3.3: Locate the slice data of the encoded data, divide the slice data into four equal parts, perform local conversions on the four divided slice data respectively, and assign the results of the local conversions to the original positions of the slice data to complete the decryption of each video frame of the medical imaging video.

[0045] The methods for performing local conversions on the four divided slice data in Step S1 and Step S3 are as follows:

[0046] Take the first eight bits of the first slice data and perform an exclusive OR operation with the hexadecimal code 0xEF bit by bit, and assign the result of the exclusive OR operation to the first eight bits of the first slice data;

[0047] Take the first eight bits of the second slice data and perform an exclusive OR operation with the hexadecimal code 0xDE bit by bit, and assign the result of the exclusive OR operation to the first eight bits of the second slice data;

[0048] Take the first eight bits of the third slice data and perform an exclusive OR operation with the hexadecimal code 0xCD bit by bit, and assign the result of the exclusive OR operation to the first eight bits of the third slice data;

[0049] Take the first eight bits of the fourth slice data and perform an exclusive OR operation with the hexadecimal code 0xBC, and assign the result of the exclusive OR operation to the first eight bits of the fourth slice data.

[0050] The measured effect diagram of a 4K medical image content interference protection method designed by the present invention is referred to Figure 4 , when using a third-party player, intercept the playback of medical image data, display it as a mosaic, and cannot normally display the original medical image; when using a player with the interference decryption function designed by the present invention to play, the picture can be restored normally.

[0051] In summary, the method designed by the present invention only modifies four eight-byte of each slice data, and the computational complexity is very limited. Even when encountering 4K key frames, the resource occupancy is small, and the real-time performance of medical images is also little affected.

[0052] The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various changes can be made without departing from the gist of the present invention.

Claims

1. A 4K medical imaging content interference protection method, characterized in that: For medical image videos, perform the following steps S1 to S3 to complete the encryption and decryption processing of the medical image videos: Step S1: at the transmitting end of the medical image video to be transmitted, for each video frame of the medical image video, the slice data is searched, and the slice data is divided into a preset number of pieces, and each of the divided slice data is locally converted to complete the encryption processing of the medical image video to be transmitted; The specific steps of step S1 are as follows: Step S1.1: Encode each video frame of the medical image video to obtain encoded data, and search for a network abstraction layer unit for the encoded data. If found, execute step S1.2; otherwise, transmit the encoded data over the network through a standard transmission protocol; Step S1.2: searching for the header of the coded data, if found, executing step S1.3, otherwise transmitting the coded data over the network via a standard transmission protocol; Step S1.3: Find the slice data of the coded data, divide the slice data into four equal parts, perform local conversion on the four divided slice data respectively, assign the local conversion results to the original positions of the slice data respectively, and complete the encryption of each video frame of the medical imaging video; Step S2: Transmitting the encrypted medical imaging video via a standard transmission protocol; Step S3: receiving the encrypted medical image video at the receiving end, searching for slice data of each video frame of the received medical image video, dividing the slice data into a preset number of pieces, performing the same local conversion as step S1 on each of the divided slice data, and completing the decryption processing of the received medical image video; The specific steps of step S3 are as follows: Step S3.1: receiving the encrypted medical imaging video at the receiving end and assembling the coded data of each video frame; searching for the network abstraction layer unit, if found, executing step S3.2, otherwise performing conventional decoding and rendering on the coded data; Step S3.2: Search for the header of the coded data. If found, execute step S3.

3. Otherwise, perform conventional decoding and rendering on the coded data. Step S3.3: Find the slice data of the encoded data, divide the slice data into four equal parts, perform local conversion on the four divided slice data respectively, assign the local conversion results to the original positions of the slice data respectively, and complete the decryption of each video frame of the medical imaging video; The method for performing local conversion on the divided four pieces of data in step S1.3 and step S3.3 is as follows: Take the first eight bits of the first slice data and perform bitwise XOR operation with the hexadecimal code 0xEF, and assign the result of the XOR operation to the first eight bits of the first slice data; Take the first eight bits of the second piece of data and perform bitwise XOR operation with the hexadecimal code 0xDE, and assign the result of the XOR operation to the first eight bits of the second piece of data; Take the first eight bits of the third piece of data and perform bitwise XOR operation with the hexadecimal code 0xCD, and assign the result of the XOR operation to the first eight bits of the third piece of data; Take the first eight bits of the fourth piece of data and perform a bitwise XOR operation with the hexadecimal code 0xBC, and assign the result of the XOR operation to the first eight bits of the fourth piece of data.

2. A 4K medical imaging content interference protection method according to claim 1, characterized in that: The medical image video format is the H264\H265 standard encoding format.

3. A 4K medical imaging content interference protection method according to claim 1, characterized in that: The standard transmission protocol includes one or more of RTSP, RTMP, and SRT transmission protocols.

Images