A secure transmission system for passport data

Abstract

The application relates to the technical field of secure transmission, and discloses a secure transmission system for passport data, which comprises the following steps: performing NFC normalization and NFD normalization on an original passport name field respectively to obtain a first byte sequence and a second byte sequence; performing remainder operation on the first byte length and the second byte length of the first byte sequence and the second byte sequence to obtain a first remainder and a second remainder respectively and generate a shock phase residual; judging whether the first byte length or the second byte length enters a boundary adjacent interval defined by the maximum allowed byte length of a target transmission node and a safety margin, and then inserting k zero amplitude characters at the tail of the passport name field to form DEP expansion padding; constructing a node vector of a corresponding target transmission node for each target transmission node based on the DEP expansion padding; and comparing the node vectors of adjacent target transmission nodes to determine a secure transmission alarm of the passport name field.

Description

Technical Field

[0001] This invention relates to the field of secure transmission technology, and more specifically, to a secure transmission system for passport data. Background Technology

[0002] In the digital clearance environment of international aviation, cruise ships, and border crossings, passenger passport data must continuously traverse multiple levels of links, including airline systems, direct access points to travel agencies, and customs and counter-terrorism databases. This includes cloud platforms using UTF-8 encoding, as well as legacy nodes still using Latin-1, ASCII, or other local encodings. To balance real-time performance and compatibility, name fields are often dynamically normalized and truncated by byte length, then encrypted and forwarded using multiple parallel channels such as cellular, satellite, and VPN. Even slight processing differences at any node can trigger a complete identity veto or erroneous merging downstream.

[0003] Therefore, the following technical problems exist:

[0004] When the same passenger's name undergoes normalization switching between NFC and NFD in the data link, the byte sequence length oscillates with a short period. When the length after oscillation happens to fall exactly on the maximum number of bytes specified by the protocol, some nodes will perform hard pruning on the field. In this way, two records that are visually identical but actually have different code point sequences will collide into one after being downgraded to ASCII, resulting in pseudo-same name conflicts, mismatches between blacklists and whitelists, and thus causing security risks. Summary of the Invention

[0005] This invention provides a secure transmission system for passport data, solving the technical problems mentioned in the background art.

[0006] This invention provides a secure transmission system for passport data, comprising:

[0007] The field processing module is used to perform NFC normalization and NFD normalization on the original passport name field to obtain the first byte sequence and the second byte sequence; and to perform a modulo operation on the first byte length and the second byte length of the first byte sequence and the second byte sequence to obtain the first modulo and the second modulo respectively and generate the oscillation phase residual code.

[0008] The scaling padding module is used to determine whether the length of the first byte or the length of the second byte enters the boundary range defined by the maximum allowed byte length and the safety margin of the target transmission node. If so, k zero characters are inserted at the end of the passport name field to form DEP scaling padding.

[0009] The node vector module is used to construct the corresponding node vector for each target transmission node based on DEP scaling and padding.

[0010] The secure transmission module is used to compare the node vectors of adjacent target transmission nodes to determine secure transmission alerts for the passport name field.

[0011] The field tracing module is used to perform field tracing processing based on the node vector received at the target transmission endpoint to obtain the original passport name field.

[0012] Furthermore, NFC normalization and NFD normalization are performed on the passport name field respectively to obtain the first byte sequence and the second byte sequence, including:

[0013] Confirm that the passport name field S is a valid Unicode string and is encoded in UTF-8.

[0014] Apply the NFC normalization function to the passport name field S to obtain the NFC normalization result. Reencode the NFC normalization result into a UTF-8 byte sequence to obtain the first byte sequence and record the length of the first byte.

[0015] Apply the NFD normalization function to the passport name field S to obtain the NFD normalization result. Reencode the NFD normalization result into a UTF-8 byte sequence to obtain the second byte sequence, and record the length of the second byte.

[0016] Furthermore, a modulo operation is performed on the lengths of the first and second bytes of the first and second byte sequences to obtain the first and second modulos, respectively, including:

[0017] Step 31, select coprime prime numbers. and ;

[0018] Step 32, based on prime numbers Perform a modulo operation on the length of the first byte to obtain the first modulo. ;

[0019] Step 33, based on prime numbers Perform a modulo operation on the length of the second byte to obtain the second modulo. .

[0020] Furthermore, the oscillating phase residual code is generated, including:

[0021] Calculate the minimum binary bit width for the first and second remainder operations respectively, to obtain the first bit width and the second bit width, and ensure that the sum of the first bit width and the second bit width is ≤ 16; otherwise, return to step 31 and reselect coprime prime numbers. and Continue until the sum of the first width and the second width is ≤ 16;

[0022] Use the second bit width as the number of bits to shift left. ;

[0023] The oscillation phase residual code is generated based on the left shift bit, as follows:

[0024] ;

[0025] in, Indicates the residual code of the oscillation phase. This represents a left shift operation. This indicates a bitwise OR operation.

[0026] Furthermore, determining whether the length of the first byte or the length of the second byte falls within the boundary adjacent to the maximum allowed byte length of the target transmission node and the safety margin includes:

[0027] Read the maximum allowed byte length and safety margin from the configuration table of the target transmission node;

[0028] The difference between the maximum allowed byte length and the safety margin is used as the lower bound of the boundary.

[0029] The length of the first byte and the length of the second byte are compared with the lower boundary limit respectively. If the length of the first byte or the length of the second byte is greater than or equal to the lower boundary limit, the length of the first byte or the length of the second byte is marked as 1; otherwise, it is marked as 0.

[0030] Perform a bitwise OR operation on the first byte length and the second byte length of the flag to obtain the global boundary risk flag.

[0031] Furthermore, insert k zero-width characters at the end of the passport name field to form DEP stretch padding, including:

[0032] If the global boundary risk flag is equal to 1, then there is a risk of clipping in the passport name field;

[0033] If there is a risk of clipping in the passport name field, the following steps should be performed in sequence:

[0034] Choose the maximum value between the first byte length and the second byte length as the coverage length;

[0035] The sum of the maximum allowed byte length and the safety margin is calculated, and the difference between this sum and the overwrite length is used to obtain the number of zero-width characters, k.

[0036] Create k zero-character fields and insert them at the end of the passport name field to form DEP stretch padding.

[0037] Furthermore, based on DEP scaling and padding, a node vector corresponding to each target transmission node is constructed, including:

[0038] The node vector includes: DEP stretch padding, oscillation phase residual code, number of zero-amplitude characters, left shift bits, first bit width, and second bit width.

[0039] Furthermore, the node vectors of adjacent target transmission nodes are compared to determine security transmission alerts for the passport name field, including:

[0040] Obtain the i-th node vector and the (i+1)-th node vector of the i-th target transmission node and the (i+1)-th target transmission node. If the i-th node vector and the (i+1)-th node vector are different, and either the i-th node vector or the (i+1)-th node vector contains... If the value is greater than 0, a security transmission alert will be output for the passport name field.

[0041] Furthermore, based on the node vector received at the target transmission endpoint, field tracing processing is performed to obtain the original passport name field, including:

[0042] In response to a security transmission alert for the passport name field, perform the following actions:

[0043] Step 91, if the number of zero characters is greater than 0 and the number of zero characters is less than or equal to the sum of the safety margin and 1, then the original passport name field is determined to be corrupted; otherwise, proceed to step 92.

[0044] Step 92: Extract the second remainder from the oscillation phase residual code based on the second bit width, and extract the first remainder from the oscillation phase residual code based on the number of left shifts;

[0045] Step 93: If the DEP stretch padding contains k consecutive zero characters, then strip the k zero characters to obtain the passport name field to be confirmed.

[0046] Step 94: Perform NFC normalization and NFD normalization on the name field of the passport to be confirmed and re-encode it into UTF-8 to obtain the first verification byte length and the second verification byte length.

[0047] Step 95, based on prime numbers The first verification remainder is obtained by taking the remainder of the length of the first verification byte; based on prime numbers. Take the remainder of the second verification byte length to obtain the second verification remainder. If the first verification remainder is equal to the first remainder and the second verification remainder is equal to the second remainder, then the tracing is successful and the passport name field to be confirmed is used as the original passport name field; otherwise, the tracing fails.

[0048] If there is no response to the security transmission alert for the passport name field, perform the following action:

[0049] Step 96: If the DEP stretch padding contains k consecutive zero characters, then strip the k zero characters to obtain the original passport name field.

[0050] The beneficial effects of this invention are as follows: It jointly models the normalized oscillations and length pruning boundary collisions that may occur in the passport name field in a multi-character set link. By introducing the oscillation phase residual code and the DEP scaling and padding mechanism, the normalized oscillations and length pruning boundaries can be identified in real time in the transmission link, and can be effectively avoided and accurately traced without interrupting the normal transmission process. It can realize end-to-end consistency control and reliable restoration of the passport name field in complex scenarios such as cross-encoding, asynchronous pruning, and multi-node transmission, and significantly improve the security, compatibility and traceability of passport data in cross-border transfer. Attached Figure Description

[0051] Figure 1 This is a block diagram of a secure transmission system for passport data according to the present invention. Detailed Implementation

[0052] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0053] like Figure 1 As shown, a secure transmission system for passport data includes:

[0054] The field processing module is used to perform NFC normalization and NFD normalization on the original passport name field to obtain the first byte sequence and the second byte sequence; and to perform a modulo operation on the first byte length and the second byte length of the first byte sequence and the second byte sequence to obtain the first modulo and the second modulo respectively and generate the oscillation phase residual code.

[0055] The scaling padding module is used to determine whether the length of the first byte or the length of the second byte enters the boundary range defined by the maximum allowed byte length and the safety margin of the target transmission node. If so, k zero characters are inserted at the end of the passport name field to form DEP scaling padding.

[0056] The node vector module is used to construct the corresponding node vector for each target transmission node based on DEP scaling and padding.

[0057] The secure transmission module is used to compare the node vectors of adjacent target transmission nodes to determine secure transmission alerts for the passport name field.

[0058] The field tracing module is used to perform field tracing processing based on the node vector received at the target transmission endpoint to obtain the original passport name field.

[0059] In one embodiment of the present invention, NFC normalization and NFD normalization are performed on the passport name field to obtain a first byte sequence and a second byte sequence, including:

[0060] Confirm that the passport name field S is a valid Unicode string and is encoded in UTF-8.

[0061] Before byte-level processing, it is necessary to ensure that the input data is in a valid and predictable encoding format to eliminate subsequent normalization and length statistics errors caused by non-UTF-8 or illegal code points, and to provide a unified starting point for double-normalized oscillation detection.

[0062] Apply the NFC normalization function to the passport name field S to obtain the NFC normalization result. Reencode the NFC normalization result into a UTF-8 byte sequence to obtain the first byte sequence and record the length of the first byte.

[0063] All decomposable characters are combined into a single pre-combined form to eliminate possible code point dispersion variants from different input stages, generate the first byte sequence and record the length of the first byte, the length of the first byte directly reflects the number of bytes occupied by the first byte sequence;

[0064] Apply the NFD normalization function to the passport name field S to obtain the NFD normalization result. Reencode the NFD normalization result into a UTF-8 byte sequence to obtain the second byte sequence, and record the length of the second byte.

[0065] Similarly, the length of the second byte directly reflects the number of bytes occupied by the second byte sequence.

[0066] In one embodiment of the present invention, a modulo operation is performed on the first byte length and the second byte length of the first byte sequence and the second byte sequence to obtain a first modulo and a second modulo, respectively, including:

[0067] Step 31, select coprime prime numbers. and ;

[0068] To map the two normalized byte lengths to a finite, distinguishable phase space, two coprime modulo primes must be selected. and Coprime primes and To ensure that the combined period of the first and second remainders obtained by taking the remainders of the first byte length and the second byte length respectively is maximized, the same residual pair is avoided from being generated in different oscillation modes.

[0069] Step 32, based on prime numbers Perform a modulo operation on the length of the first byte to obtain the first modulo. ;

[0070] By using the modulo operation, the length of the first byte, which may be greater than the maximum value of the protocol, is mapped to 0 to... The first remainder between the two values, where the first remainder is an integer, reflects the length of the combinational state modulo 1. Spatial location, when the length of the first byte spans multiple transmission nodes oscillates. At that time, the first remainder will jump periodically.

[0071] Step 33, based on prime numbers Perform a modulo operation on the length of the second byte to obtain the second modulo. .

[0072] By using the modulo operation, the length of the second byte, which may be greater than the maximum value of the protocol, is mapped to 0 to... The second remainder, which is an integer, reflects the length of the combination state modulo 1. Spatial location, when the length of the second byte spans multiple transmission nodes oscillations. At that time, the second remainder will jump periodically.

[0073] In one embodiment of the present invention, generating the oscillating phase residual code includes:

[0074] Calculate the minimum binary bit width for the first and second remainder operations respectively, to obtain the first bit width and the second bit width, and ensure that the sum of the first bit width and the second bit width is ≤ 16; otherwise, return to step 31 and reselect coprime prime numbers. and Continue until the sum of the first width and the second width is ≤ 16;

[0075] Before concatenating the first and second remainders into the oscillating phase residual code, it is necessary to determine the minimum number of bits that the first and second remainders can occupy; otherwise, it is impossible to guarantee no overlap or restore the original code after concatenation.

[0076] The first bit width represents the minimum number of bits in binary for the first remainder, and the second bit width represents the minimum number of bits in binary for the second remainder.

[0077] To concatenate the first and second remainders into a 16-bit field, the sum of the first and second bit widths must not exceed 16. If it does, a smaller prime number must be selected to reduce the bit width.

[0078] Ensure that the final generated oscillation phase residual code can be stored in a 16-bit unsigned integer and that it occupies a fixed two bytes in the hardware or protocol message.

[0079] It should be noted that 16 is the maximum bit width of the residual code as agreed in the protocol, to ensure message compatibility.

[0080] Use the second bit width as the number of bits to shift left. ;

[0081] When splicing, the first remainder needs to be shifted to the left first. The lower position is used to free up space for the second remainder.

[0082] The oscillation phase residual code is generated based on the left shift bit, as follows:

[0083] ;

[0084] in, Indicates the residual code of the oscillation phase. This represents a left shift operation. This indicates a bitwise OR operation.

[0085] The oscillating phase residual code carries phase information of both the combination state (first remainder) and the decomposition state (second remainder), and its length is fixed at the first bit width and the second bit width less than or equal to 16 bits.

[0086] In one embodiment of the present invention, determining whether the length of the first byte or the length of the second byte enters the boundary adjacent to the maximum allowed byte length of the target transmission node and the safety margin includes:

[0087] Read the maximum allowed byte length and safety margin from the configuration table of the target transmission node;

[0088] Different target transmission nodes may have different protocol limits and acceptable buffer margins.

[0089] The maximum allowed byte length indicates the maximum number of bytes that the target transmission node (such as a border inspection system, airline server, etc.) can accept in its protocol or hardware interface for the passport name field.

[0090] Buffer margin represents the extra byte space reserved to withstand short-term byte count fluctuations caused by normalization oscillations. When a field is passively or actively filled, it can safely accommodate the sum of the maximum allowed byte length and the buffer margin.

[0091] The difference between the maximum allowed byte length and the safety margin is used as the lower bound of the boundary.

[0092] To determine the risk of near-clipping, it is necessary to distinguish between the completely safe zone and the dangerous near zone, and use the difference between the maximum allowed byte length and the safety margin as the lower boundary limit; the lower boundary limit means that if the length of the first byte or the length of the second byte is greater than or equal to the lower boundary limit, it is considered to have entered the near zone.

[0093] The length of the first byte and the length of the second byte are compared with the lower boundary limit respectively. If the length of the first byte or the length of the second byte is greater than or equal to the lower boundary limit, the length of the first byte or the length of the second byte is marked as 1; otherwise, it is marked as 0.

[0094] A Boolean flag of 1 or 0 indicates whether the NFC and NFD normalized view are in an adjacency state;

[0095] There is a risk of pruning if the length of the first byte or the second byte reaches or exceeds the lower limit.

[0096] Perform a bitwise OR operation on the first byte length and the second byte length of the flag to obtain the global boundary risk flag.

[0097] A fill or alarm should be triggered whenever either normalized view is in proximity, without requiring both the NFC and NFD normalized views to be in proximity simultaneously.

[0098] In one embodiment of the invention, k zero-character lines are inserted at the end of the passport name field to form DEP stretch padding, including:

[0099] If the global boundary risk flag is equal to 1, then there is a risk of clipping in the passport name field;

[0100] Filling should only be initiated when the previously generated global boundary risk flag indicates that the length of the pre-combined or decomposed state has entered an adjacency state.

[0101] If there is a risk of clipping in the passport name field, the following steps should be performed in sequence:

[0102] Choose the maximum value between the first byte length and the second byte length as the coverage length;

[0103] In NFC and NFD normalized views, the side with the larger number of bytes is closest to the pruning threshold. Covering the length in this way can avoid the pruning risk of both states at once.

[0104] The sum of the maximum allowed byte length and the safety margin is calculated, and the difference between this sum and the overwrite length is used to obtain the number of zero-width characters, k.

[0105] To move the total field length away from the danger zone and into the safe zone, the number of characters to be inserted needs to be calculated.

[0106] The fill quantity k is used to push the field above the threshold but within the margin range, eliminating the risk of pruning.

[0107] Create k zero-character fields and insert them at the end of the passport name field to form DEP stretch padding.

[0108] Only by inserting zero-width characters that occupy bytes but not display width at the end of the field can the byte length be truly changed in the transmission and clipping mechanisms without affecting the visual appearance.

[0109] In one embodiment of the present invention, constructing a node vector for each target transmission node based on DEP scaling padding includes:

[0110] The node vector includes: DEP stretch padding, oscillation phase residual code, number of zero-amplitude characters, left shift bits, first bit width, and second bit width.

[0111] In one embodiment of the present invention, comparing the node vectors of adjacent target transmission nodes to determine a security transmission alert for the passport name field includes:

[0112] Obtain the i-th node vector and the (i+1)-th node vector of the i-th target transmission node and the (i+1)-th target transmission node. If the i-th node vector and the (i+1)-th node vector are different, and either the i-th node vector or the (i+1)-th node vector contains... If the value is greater than 0, a security transmission alert will be output for the passport name field.

[0113] To determine where the normalized oscillation and DEP scaling padding coupling occur in the link, the node vectors of the two adjacent hops must be obtained. Changes in the node vectors indicate oscillations in the NFC or NFD normalized view, as well as DEP scaling padding operations. A value greater than 0 indicates that the transmission node has cropped the passport name field to mitigate risks.

[0114] In one embodiment of the present invention, field tracing processing is performed based on the node vector received at the target transmission endpoint to obtain the original passport name field, including:

[0115] In response to a security transmission alert for the passport name field, perform the following actions:

[0116] Step 91: If the number of zero characters is greater than 0 and the number of zero characters is less than or equal to the sum of the safety margin and 1, then the original passport name field is determined to be corrupted; otherwise, proceed to step 92.

[0117] When the target terminal receives a field with zero padding at the end (k>0), it is necessary to determine whether the padding is within an acceptable safety margin. If k>0, it is confirmed that anti-clipping padding has indeed occurred. Then, k≤(safety margin+1) is used to verify that the padding amount does not exceed the reversible range. Otherwise, it is considered that the field has been abnormally tampered with or damaged.

[0118] Step 92: Extract the second remainder from the oscillation phase residual code based on the second bit width, and extract the first remainder from the oscillation phase residual code based on the number of left shifts;

[0119] If there is no abnormal fill amount, the length residue under the two normalized views needs to be recovered from the oscillation phase residual code in order to verify whether the field was unintentionally modified in the link;

[0120] Step 93: If the DEP stretch padding contains k consecutive zero characters, then strip the k zero characters to obtain the passport name field to be confirmed.

[0121] After confirming that there is no damage and the remnants have been restored, the tail padding must be cleared to obtain the passport name field to be confirmed.

[0122] Step 94: Perform NFC normalization and NFD normalization on the name field of the passport to be confirmed and re-encode it into UTF-8 to obtain the first verification byte length and the second verification byte length.

[0123] After removing the padding, the actual byte length in both views needs to be recalculated to verify whether it is consistent with the original modulo operation.

[0124] Step 95, based on prime numbers The first verification remainder is obtained by taking the remainder of the length of the first verification byte; based on prime numbers. Take the remainder of the second verification byte length to obtain the second verification remainder. If the first verification remainder is equal to the first remainder and the second verification remainder is equal to the second remainder, then the tracing is successful and the passport name field to be confirmed is used as the original passport name field; otherwise, the tracing fails.

[0125] End-to-end consistency checks must accurately compare the recalculated length residual with the residual transmitted through the link.

[0126] The first verification remainder and the second verification remainder are generated using the same remainder operation as in steps 32 and 33. They are then compared with the previously recovered first remainder and second remainder to confirm that the field has not been altered.

[0127] If there is no response to the security transmission alert for the passport name field, perform the following action:

[0128] Step 96: If the DEP stretch padding contains k consecutive zero characters, then strip the k zero characters to obtain the original passport name field.

[0129] If no secure transmission alert is triggered, the field is directly restored by stripping and filling. This quickly restores the original name field, satisfying both performance and accuracy requirements in typical scenarios.

[0130] The embodiments of this example have been described above. However, this example is not limited to the specific implementation methods described above. The specific implementation methods described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms based on the guidance of this example, and all of them are within the protection scope of this example.

Claims

1. A secure transmission system for passport data, characterized in that, include: The field processing module performs NFC normalization and NFD normalization on the original passport name field to obtain the first byte sequence and the second byte sequence, including: Confirm that the passport name field S is a valid Unicode string and is encoded in UTF-8. Apply the NFC normalization function NFC(S) to the passport name field S to obtain the NFC normalization result. Reencode the NFC normalization result into a UTF-8 byte sequence to obtain the first byte sequence and record the length of the first byte. Apply the NFD normalization function NFD(S) to the passport name field S to obtain the NFD normalization result. Reencode the NFD normalization result into a UTF-8 byte sequence to obtain the second byte sequence, and record the length of the second byte. The modulo operation is performed on the lengths of the first and second bytes of the first and second byte sequences to obtain the first and second modulos respectively, and to generate the oscillating phase residual code, including: Step 31, select coprime prime numbers. and ; Step 32, based on prime numbers Perform a modulo operation on the length of the first byte to obtain the first modulo. ; Step 33, based on prime numbers Perform a modulo operation on the length of the second byte to obtain the second modulo. ; Calculate the minimum binary bit width of the first and second remainders respectively, to obtain the first bit width and the second bit width, and ensure that the sum of the first bit width and the second bit width is ≤16; otherwise, return to step 31 and reselect coprime prime numbers. and Continue until the sum of the first width and the second width is ≤ 16; Use the second bit width as the number of bits to shift left. ; The oscillation phase residual code is generated based on the left shift bit, as follows: ； in, Indicates the residual code of the oscillation phase. This represents a left shift operation. Indicates a bitwise OR operation; The scaling padding module determines whether the length of the first byte or the second byte falls within the boundary range defined by the maximum allowed byte length and safety margin of the target transmission node. If so, it inserts k zero-width characters at the end of the passport name field to form DEP scaling padding, including: Read the maximum allowed byte length and safety margin from the configuration table of the target transmission node; The difference between the maximum allowed byte length and the safety margin is used as the lower bound of the boundary. The length of the first byte and the length of the second byte are compared with the lower boundary limit respectively. If the length of the first byte or the length of the second byte is greater than or equal to the lower boundary limit, the length of the first byte or the length of the second byte is marked as 1; otherwise, it is marked as 0. Perform a bitwise OR operation on the first byte length and the second byte length of the flag to obtain the global boundary risk flag; If the global boundary risk flag is equal to 1, then there is a risk of clipping in the passport name field; If there is a risk of clipping in the passport name field, the following steps should be performed in sequence: Choose the maximum value between the first byte length and the second byte length as the coverage length; The sum of the maximum allowed byte length and the safety margin is calculated, and the difference between this sum and the overwrite length is used to obtain the number of zero-width characters, k. Create k zero-character fields and insert them at the end of the passport name field to form DEP (Dual Expanded Fill). The node vector module is used to construct the corresponding node vector for each target transmission node based on DEP scaling padding, including: DEP scaling padding, oscillation phase residual code, number of padding zero amplitude characters, number of left shift bits, first bit width and second bit width; The secure transmission module is used to compare the node vectors of adjacent target transmission nodes to determine secure transmission alerts for the passport name field. The field tracing module is used to perform field tracing processing based on the node vector received at the target transmission endpoint to obtain the original passport name field.

2. The secure transmission system for passport data according to claim 1, characterized in that, Compare the node vectors of adjacent target transmission nodes to determine security transmission alerts for the passport name field, including: Obtain the i-th node vector and the (i+1)-th node vector of the i-th target transmission node and the (i+1)-th target transmission node. If the i-th node vector and the (i+1)-th node vector are different, and either the i-th node vector or the (i+1)-th node vector contains... If the value is greater than 0, a security transmission alert will be output for the passport name field.

3. A secure transmission system for passport data according to claim 2, characterized in that, Field tracing is performed based on the node vector received at the target transmission endpoint to obtain the original passport name field, including: In response to a security transmission alert for the passport name field, perform the following actions: Step 91: If the number of zero characters is greater than 0 and the number of zero characters is less than or equal to the sum of the safety margin and 1, then the original passport name field is determined to be corrupted; otherwise, proceed to step 92. Step 92: Extract the second remainder from the oscillation phase residual code based on the second bit width, and extract the first remainder from the oscillation phase residual code based on the number of left shifts; Step 93: If the DEP stretch padding contains k consecutive zero characters, then strip the k zero characters to obtain the passport name field to be confirmed. Step 94: Perform NFC normalization and NFD normalization on the name field of the passport to be confirmed and re-encode it into UTF-8 to obtain the first verification byte length and the second verification byte length. Step 95, based on prime numbers The first verification remainder is obtained by taking the remainder of the length of the first verification byte; based on prime numbers. Take the remainder of the second verification byte length to obtain the second verification remainder. If the first verification remainder is equal to the first remainder and the second verification remainder is equal to the second remainder, then the tracing is successful and the passport name field to be confirmed is used as the original passport name field; otherwise, the tracing fails. If there is no response to the security transmission alert for the passport name field, perform the following action: Step 96: If the DEP stretch padding contains k consecutive zero characters, then strip the k zero characters to obtain the original passport name field.

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