Electronic contract content encryption method and system based on sequence decomposition

Abstract

The invention provides an electronic contract content encryption method and system based on sequence decomposition, and belongs to the technical field of electronic contract content encryption. The method comprises the steps of obtaining contract content of an electronic contract; based on the word frequency of the keyword set extracted from the contract content, performing content encryption processing on the contract content to generate a content ciphertext; and based on the offset position and word frequency of the keyword in the keyword set, generating a mapping parameter, performing encryption processing on the mapping parameter, and generating the encrypted mapping parameter at the same time. The method comprises the following steps: extracting keywords from contract contents according to a preset sequence structure, and performing content encryption processing on the contract contents according to word frequencies of the keywords to generate content ciphertexts; and then generating a mapping parameter by utilizing the offset position and word frequency of the keyword, and performing encryption distribution processing on the content ciphertext in combination with a contract offset structure.

Description

Technical Field

[0001] This invention belongs to the field of electronic contract content encryption technology, specifically relating to an electronic contract content encryption method and system based on sequence decomposition. Background Technology

[0002] Electronic contracts, as legal documents that carry the rights and obligations of both parties to a transaction and build commercial trust, improve signing efficiency, simplify management processes, and reduce storage costs. However, in the transmission and storage stages, it is necessary to ensure the confidentiality, integrity, and non-repudiation of the contract content.

[0003] Existing technologies use digital certificates to authenticate identities, combined with transport layer encryption protocols, to ensure the security of electronic contract transmission. However, such solutions have many inherent defects and security bottlenecks in practice. Because their security system relies on the validity of certificates, it constitutes a single point of failure. When certificates are leaked due to mismanagement, expire for any reason, or the root trust chain of the certificate authority is broken, all electronic contracts relying on this certificate system will face the risk of being stolen or tampered with in bulk. At the same time, existing technologies cannot dynamically assess the risks of the transmission environment while the contract content remains encrypted. The system lacks real-time awareness of abnormal traffic in the transmission link or threats such as network attacks, resulting in its protection mechanism being in a passive and lagging state, unable to make adaptive adjustments according to changes in risk levels.

[0004] In view of this, the present invention proposes an electronic contract content encryption method and system based on sequence decomposition. Summary of the Invention

[0005] The purpose of this invention is to provide an electronic contract content encryption method and system based on sequence decomposition, in order to solve the problem that existing technologies only encrypt the transmission path, resulting in the direct theft of contract document content by attackers.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: an electronic contract content encryption method based on sequence decomposition, the method comprising: obtaining the contract content of the electronic contract; and performing content encryption processing on the contract content based on the word frequency of a set of keywords extracted from the contract content to generate ciphertext; Based on the offset positions and frequencies of keywords in the keyword set, mapping parameters are generated and encrypted, and encrypted mapping parameters are generated. Based on the ciphertext content and the encrypted mapping parameters, encrypted distribution processing is performed to generate an encrypted summary. The process of encrypting the contract content based on the word frequency of the keyword set extracted from the contract content includes: extracting a keyword set from the contract content according to a preset order structure; calculating the word frequency of each keyword in the keyword set in the contract content; generating an encrypted dataset based on the word frequency; and using the encrypted dataset to encrypt the contract content.

[0007] Preferably, generating encrypted mapping parameters includes: defining the offset position of the keyword and the corresponding word frequency as a set of original parameters; constructing a mathematical mapping function based on the original parameters and generating corresponding mapping parameters for each set of original parameters; and encrypting the mapping parameters.

[0008] Preferably, the encrypted distribution processing based on the encrypted content and the encrypted mapping parameters includes: generating a contract offset structure that is consistent with the preset order structure based on the encrypted mapping parameters; It also performs encrypted distribution processing on the ciphertext of the content by taking the encrypted mapping parameters as input and combining them with the contract offset structure.

[0009] Preferably, the method further includes: generating a decryption key for decrypting the ciphertext of the content based on the mapping parameters; and using the decryption key to perform decryption processing on the ciphertext of the content to restore the contract content.

[0010] An electronic contract content encryption system based on sequence decomposition, the system includes: a content encryption module, used to obtain the contract content of the electronic contract, and perform content encryption processing on the contract content based on the word frequency of a set of keywords extracted from the contract content, so as to generate ciphertext content; The parameter encryption module is used to generate mapping parameters based on the offset position and word frequency of keywords in the keyword set, and to encrypt the mapping parameters to generate encrypted mapping parameters. The encrypted distribution module is used to perform encrypted distribution processing based on the ciphertext content and the encrypted mapping parameters to generate an encrypted digest; The content decryption module is used to generate a decryption key based on the mapping parameters, and then use the decryption key to perform decryption processing on the ciphertext content.

[0011] Preferably, the content encryption module is configured to: extract a set of keywords from the contract content according to a preset order structure; and count the word frequency of each keyword in the keyword set in the contract content. It also generates encrypted datasets based on word frequency and uses these encrypted datasets to encrypt contract content.

[0012] Preferably, the parameter encryption module is configured to define the offset position of the keyword and the corresponding word frequency as a set of raw parameters; A mathematical mapping function is constructed based on the original parameters to generate the mapping parameters; and the mapping parameters are then encrypted.

[0013] Preferably, the encrypted distribution module is configured to perform encrypted distribution processing based on the ciphertext content and the encrypted mapping parameters to generate an encrypted digest.

[0014] Preferably, the encrypted distribution module is further configured to: generate a contract offset structure that is consistent with the preset order structure based on the encrypted mapping parameters; It also performs encrypted distribution processing on the ciphertext of the content by taking the encrypted mapping parameters as input and combining them with the contract offset structure.

[0015] Preferably, the content decryption module is configured to generate a decryption key for decrypting the ciphertext based on the mapping parameters; And use the decryption key to decrypt the ciphertext of the content in order to restore the contract content.

[0016] Beneficial effects 1. This invention extracts keywords from the contract content according to a preset sequence structure, performs content encryption processing on the contract content based on the word frequency of the keywords to generate ciphertext; then, it uses the offset position of the keywords and word frequency to generate mapping parameters, and combines them with the contract offset structure to perform encryption distribution processing on the ciphertext. By constructing a dual encryption system that is deeply bound to the inherent structure and statistical characteristics of the contract content, compared with existing technologies that encrypt the entire file, it requires crackers to simultaneously restore the encryption algorithm and the specific sequence distribution of the contract content, thereby improving the confidentiality and anti-attack capability of electronic contract content.

[0017] 2. This invention defines the offset position and word frequency of keywords in the contract content as original parameters, generates mapping parameters through a mathematical mapping function, and generates a decryption key based on the mapping parameters to perform decryption processing on the encrypted content. This realizes the dynamic association between the decryption key and the contract content. Since the decryption key originates from the unique structure and statistical information of the contract content, i.e., it is a non-fixed key string, it avoids complex key management and improves the resistance to key theft or brute-force cracking. Attached Figure Description

[0018] Figure 1 This is a flowchart of the encrypted distribution processing method of the present invention; Figure 2 This is a flowchart of the decryption process method of the present invention; Figure 3 This is a system module diagram of the present invention. Detailed Implementation

[0019] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention, which is defined by the appended claims and their equivalents.

[0020] Example 1 Please see Figure 1-2 As shown in the figure, this embodiment discloses an electronic contract content encryption method based on sequence decomposition, which can encrypt contract information, prevent tampering during transmission, and perform risk prediction.

[0021] The contract content of the electronic contract is obtained. The contract content includes text data and its logical arrangement. The contract content is parsed according to the preset order structure. The document object structure is described in the form of a tree or graphical data structure, which describes the hierarchy and reference relationship between chapters, sections, articles and clauses in the contract. The arrangement is formalized. The preset order structure provides a benchmark for subsequent structured encryption. Based on a pre-defined order structure, a set of keywords is extracted from the contract content. The set of keywords originates from a pre-configured thesaurus containing high-frequency keywords in the contract field. Then, the frequency of each keyword in the contract content is counted. Based on the frequency of each keyword, an encrypted dataset is generated. Specifically, the encrypted dataset is a mapping table where each keyword generates a corresponding encrypted alias based on its word frequency using a preset calculation rule that deterministically converts any input into a unique, fixed-length value. Using this encrypted dataset, the contract content is encrypted by iterating through the contract content and replacing all appearing keywords with their corresponding encrypted aliases, thereby generating ciphertext. After this process is completed, the ciphertext is output. This step aims to eliminate the keyword statistical features of the original text, increasing the difficulty of cracking it solely through statistical analysis.

[0022] Furthermore, in order to achieve a deeper level of structural encryption, the offset position of each keyword in the keyword set within the contract content is obtained, such as the byte or character index of the first character of the keyword in the entire contract text string, and the word frequency corresponding to the keyword. The offset position and word frequency of each keyword are defined together as a set of original parameters, which uniquely describe the occurrence of the keyword in the contract. To obfuscate and abstract these original parameters, a mathematical mapping function is constructed based on the original parameters. This function converts the input pairs of original parameters, namely offset positions and word frequencies, into mapping parameters. This obfuscation of the original parameters is achieved. The mapping parameters are more evenly distributed and are not directly related to the original input in terms of value. The mathematical mapping function can employ nonlinear polynomial calculation steps or a transformation process based on the principles of elliptic curve cryptography to ensure that it is computationally infeasible to derive the original parameters from the mapping parameters in reverse. The original parameters are converted into corresponding mapped parameters using a mathematical mapping function, and the mapped parameters are then encrypted. Using a pre-agreed symmetric encryption key, the mapped parameters are encrypted through standard encryption steps to prevent them from being directly read or used in subsequent processing and transmission.

[0023] The specific mathematical formula for the mathematical mapping rule is as follows: Input: The offset position of the keyword in the contract content The frequency of this keyword in the contract content Output: Obfuscated mapping parameters .

[0024] In the formula, The mapping parameter represents a value generated after nonlinear polynomial transformation and modular arithmetic that has no direct linear relationship with the original input. It is used to hide the original position and frequency information. Indicates the offset position, which means the byte or character index of the first character of the keyword in the entire contract text string; This indicates word frequency, which means the total number of times the corresponding keyword appears in the entire contract content; Represents the transformation coefficients, which are pre-defined non-zero integer constants used to construct nonlinear polynomial transformations; The modulus is a pre-defined large prime number used to constrain the transformation result within a finite field, thereby enhancing the unidirectionality of the transformation.

[0025] Furthermore, the encrypted mapping parameters are used to construct an encrypted representation corresponding to the original contract structure and generate a contract offset structure. The contract offset structure is topologically consistent with the aforementioned preset order structure, but its node content is replaced by encrypted mapping parameters instead of the original keywords. While preserving the structural relationship, it also hides all the original position and frequency information. Then, using each encrypted mapping parameter as input and combining with the contract offset structure, perform encrypted distribution processing on the content ciphertext; the encrypted distribution processing is a secondary encryption process, which traverses each encrypted mapping parameter in the contract offset structure and uses the value of this parameter as the calculation basis; Based on this calculation basis, determine the operation area through a preset positioning rule. Specifically, during the encrypted distribution processing, according to the value of the encrypted mapping parameter, through a preset calculation such as modulo operation, determine the rules for the data scrambling operation to be performed on the content ciphertext, such as the rules for specific areas such as the starting position and length, and according to another part of this calculation basis, such as the parity or specific bit positions of the parameter value, select a specific data scrambling operation from the preset operation set, and perform this operation on the operation area. The operation set contains various operations available for encrypted distribution processing, such as byte substitution, cyclic shift, exclusive OR operation with a derived key, etc.; Through the positioning rule and the data scrambling operation, distribute the structure information in the form of data scrambling operations throughout the content ciphertext, thereby achieving a deep binding of the structure and the content. Any local tampering of the content ciphertext will cause the structure verification to fail during decryption. Based on the result of the encrypted distribution processing, calculate its overall, unique, fixed-length check value, for example, generated through the calculation steps defined by the Secure Hash Standard SHA-256 to produce an encrypted digest, which signs the integrity of the entire encrypted contract, and then output the encrypted digest.

[0026] Furthermore, when an authorized user needs to access the contract, execute the decryption process; by using the pre-agreed symmetric encryption key, perform reverse decryption processing on the received encrypted mapping parameter to restore the mapping parameter; Then, based on the restored mapping parameter, generate a decryption key for decrypting the content ciphertext, a structured key composed of a decryption operation sequence, which defines the order and parameters for reverse execution of the data scrambling operation, different from the traditional single symmetric or asymmetric key; Specifically, perform a calibration operation on each restored mapping parameter. For example, set two numerical thresholds T1 and T2, and T1 < T2. If the value of any mapping parameter is greater than T2, it is calibrated as a first-level decryption item and has a high priority in the decryption operation sequence; if its value is less than T1, it is calibrated as a second-level decryption item and has a low priority in the decryption operation sequence; if its value is between T1 and T2 and includes T1 and T2, it is calibrated as a standby decryption item, and its position in the decryption operation sequence is between the first-level and second-level decryption items; Then, all first-level decryption items, backup decryption items, and second-level decryption items are sorted sequentially to construct an ordered decryption operation sequence. This sequence is the structured decryption key. The decryption key is used to perform decryption processing on the ciphertext content. This process is the exact inverse of the encryption distribution processing and keyword replacement: according to the order and value of each item in the decryption operation sequence, the data perturbation operation applied to the ciphertext content is performed in reverse; then, using the reverse mapping of the encrypted dataset, all encrypted aliases are replaced back with their corresponding keywords to restore the contract content.

[0027] Furthermore, for the security assessment of the electronic contract transmission process: based on the original transmission path of the electronic contract, multiple transmission nodes are extracted from the original transmission path, such as the source server, the destination client, and the gateway; combined with these nodes, a network path discovery probe is performed, data packets with incremental time-to-live values ​​are sent sequentially, and the responses of intermediate nodes are recorded, and then the set of transmission paths between multiple transmission nodes is calculated. The transmission path set contains all possible routes from source to destination. The transmission path set is then output for further analysis. For each transmission path in the transmission path set, the transmission protocol used and the security layer protocol applied in the data transmission protocol are detected and determined. The combination of the transmission protocol and the security layer protocol is defined as the encryption state of the transmission path to assess its inherent security level.

[0028] Furthermore, the transmission risk assessment continues, candidate transmission paths are selected from the set of transmission paths, and the paths currently in use or planned to be used are adopted. The historical transmission duration of the candidate transmission paths is obtained, such as the time taken to transmit the same or similar files in the most recent times. The average transmission time of other paths is then calculated as a baseline performance indicator of the network environment. At the same time, the file size of the electronic contract is obtained, and the transmission risk value is calculated based on the historical transmission duration, average transmission time, and file size. The basis for this calculation logic is that transmission risk is related to the degree of abnormality in transmission latency and file size; for a large file, a longer transmission time may be within the normal range; but for a small file, the same transmission time may indicate a high risk of network congestion, packet loss, or man-in-the-middle attack. Based on the calculated transmission risk value, the transmission status of the electronic contract is determined. For example, by comparing it with a preset risk threshold, the transmission status is determined to be safe, warning, or high risk. Finally, the transmission status is output for decision-making or to trigger an automatic response mechanism.

[0029] The specific mathematical formula for the transmission risk value is as follows: Input: Historical transmission duration of candidate transmission paths Average transmission time of other transmission paths File size of electronic contracts Output: Transmission risk value .

[0030] In the formula, The output represents the transmission risk value, which quantifies the degree of abnormality of the current transmission latency relative to the network baseline and file size. A positive value indicates that the latency is higher than the average, and a negative value indicates that the latency is lower than the average. The absolute value is positively correlated with the degree of risk. One of the inputs is the historical transmission duration, which represents the average time taken by the selected candidate transmission path to transmit files of similar size recently. The second input represents the average transmission time, which means the average transmission time of the remaining available transmission paths excluding the candidate paths, and serves as the performance baseline of the current network environment. The third input indicates the file size, which refers to the file size of the electronic contract to be transmitted.

[0031] Furthermore, based on the output transmission risk value, a risk node judgment process is performed. This process is used to locate transmission performance bottlenecks. By judging factors such as latency, protocol, and bandwidth in sequence, the transmission performance problem is located to a specific risk node type. The process includes a set of ordered judgment steps: comparing the current transmission duration with a preset latency benchmark value to determine whether the current transmission duration is in an abnormal latency state; If the current duration significantly exceeds the baseline, the problem is classified as a latency node, indicating that the root cause of the problem is network latency. At the same time, the protocol stack used by the current transmission path is checked. If the preset secure transmission protocol is not used, the problem is categorized at the protocol node, indicating that the root cause is network latency. Then, the bandwidth assessment step is entered. Based on the contract file size and a preset target transmission time, the minimum required bandwidth is calculated to determine whether network congestion exists. Then, based on recent network probe data, the actual bandwidth of the current path is determined, which is the minimum data transmission rate necessary to complete the contract file transmission within the preset target transmission time. If the actual bandwidth is lower than the minimum bandwidth, it indicates network congestion. The problem is then attributed to the load node, indicating that the root cause of the problem is network congestion or insufficient bandwidth. Conversely, if the actual bandwidth meets or exceeds the minimum bandwidth, it indicates that the network capacity is sufficient and is marked as a capacity node, indicating that the current network capacity is sufficient and the performance bottleneck is not caused by bandwidth.

[0032] In summary, this invention combines the structured encryption process of contract content with the dynamic risk assessment of the transmission process through a linkage mechanism of structured mapping and risk assessment. It utilizes multi-level parameter mapping, risk value calculation, and risk node identification to enable encryption strategies and transmission decisions to work together and improve the encryption strength of electronic contract content. By providing a solution that covers everything from contract content acquisition and encryption to transmission status determination, transmission risk calculation, and contract content restoration, we aim to improve the reliability and usability of electronic contracts.

[0033] Example 2 To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely for explaining the invention and are not intended to limit the scope of protection of the invention.

[0034] Please see Figure 3 As shown, this embodiment provides an electronic contract content encryption system based on sequence decomposition. It generates dynamic encryption parameters, such as the word frequency and offset position of keywords, according to the structural characteristics of the contract content itself, to provide multi-level and high-strength encryption protection for the electronic contract content and generate encrypted digests for easy storage and verification. In its implementation, the system can be deployed in computing environments, including embedded devices such as computers, and interact with the electronic contract management platform through application programming interfaces or data buses.

[0035] The system includes the following modules: The content encryption module is used to perform content encryption processing; By acquiring the content of the electronic contract to be processed, a set of keywords is extracted from the contract content according to a preset order structure. The preset order structure can be a dictionary containing general keywords in the fields of law and commerce, or a special terminology customized for a specific contract type, which defines the extraction rules and priorities of the keywords. After extracting the keyword set, the contract content is traversed and analyzed to count the frequency of each keyword in the contract content. Based on the counted frequency, the module generates an encrypted dataset. In a specific implementation, the encrypted dataset can be a set of symmetric encryption keys or initialization vectors generated by using the frequency of each keyword as a seed and a pseudo-random number generation algorithm or key derivation function. This transforms the statistical characteristics of the content into cryptographic parameters. Then, the contract processing module uses the encrypted dataset to perform content encryption processing on the original contract content. For example, it can use standard encryption algorithms such as Advanced Encryption Standard (AES) or the Chinese national standard symmetric encryption algorithm SM4 to encrypt the contract content, thereby generating ciphertext.

[0036] The parameter encryption module is responsible for generating and encrypting mapping parameters related to the contract content structure, providing a basis for subsequent encrypted distribution processing; Identify and record the offset position of each keyword in the keyword set in the original contract content, such as the character index or byte position of its first appearance. Then define the offset position of each keyword and its corresponding word frequency as a set of original parameters. The word frequency is counted by the contract processing module or recounted by this module. For each keyword in the keyword set, there is such a unique set of original parameters. Then, based on the original parameters, a pre-defined mathematical mapping function is used to generate corresponding mapping parameters for each set of original parameters. The mathematical mapping function is used to establish a complex nonlinear relationship between the original parameters and the mapping parameters in order to hide the original statistical information. For example, the function can be a polynomial function, a hash function, or a transformation based on elliptic curves. The mapping parameters generated in this step are a new set of data that is decoupled from the original statistical features. By encrypting the mapping parameters, encrypted mapping parameters are generated to protect the critical mapping parameters. The encryption here can use an asymmetric encryption algorithm, using a public key for encryption and a private key held by the authorized party for decryption, thereby ensuring that only the authorized party can access and use these mapping parameters.

[0037] The encryption distribution module performs encryption distribution processing to generate the final encrypted digest; The system receives encrypted mapping parameters and then generates a contract offset structure that is consistent with the aforementioned preset order structure based on these parameters. This contract offset structure can be understood as a set of instructions for data rearrangement or permutation, and its specific generation logic is determined by the mapping parameters. For example, the mapping parameters can be interpreted as a series of offsets or exchange indices to guide how to segment and reassemble the ciphertext content; then, the encrypted mapping parameters are used as input as keys or seeds for further encryption or scrambling operations, and combined with the contract offset structure, the ciphertext content generated by the contract processing module is subjected to encrypted distribution processing. In a specific implementation, the encrypted distribution processing includes: dividing the ciphertext into multiple data blocks according to the contract offset structure, then encrypting the data blocks again using a new key derived from the mapping parameters; and rearranging these encrypted data blocks according to the order defined by the contract offset structure. After the above processing, the output is the encrypted digest; the encrypted digest is a highly obfuscated, scrambled encrypted data packet whose security depends not only on the key used to encrypt the content, but also on the encrypted mapping parameters related to the content structure.

[0038] The content decryption module is used to restore the contract content when needed, and is the reverse process of encryption. When an authorized user needs to view a contract, they need to obtain the mapping parameters. The user uses their private key to decrypt the encrypted mapping parameters to recover them. After obtaining the mapping parameters, a decryption key is generated based on these mapping parameters to decrypt the encrypted content. This generation process is the inverse process of generating an encrypted dataset based on word frequency in the contract processing module. Since the mapping parameters themselves are generated from word frequencies and offset positions, the encrypted dataset used for content encryption can be derived or reconstructed from them, thereby obtaining the decryption key; then, the generated decryption key is used to perform decryption processing on the encrypted content, for example, by using the corresponding symmetric decryption algorithm, thereby restoring the contract content; It is worth noting that in order to fully recover the contract content from the cryptographic digest, it is also necessary to first perform the reverse process of cryptographic distribution processing, that is, according to the mapping parameters and contract offset structure, reorder and decrypt the data blocks in the cryptographic digest to obtain the ciphertext of the content, and then this module performs the final decryption.

[0039] Through the collaborative work of the above modules, this embodiment deeply binds the encryption process of electronic contract content with the statistical characteristics of the content itself, generating dynamic keys and encryption structures related to the content to improve the complexity and resistance to attacks. Compared with traditional encryption methods that use fixed keys, this solution has higher adaptability and confidentiality.

Claims

1. A method for encrypting electronic contract content based on sequence decomposition, characterized in that, The method includes: obtaining the contract content of an electronic contract; and performing content encryption processing on the contract content based on the word frequency of a set of keywords extracted from the contract content to generate ciphertext. Based on the offset positions and frequencies of keywords in the keyword set, mapping parameters are generated and encrypted, and encrypted mapping parameters are generated. Based on the ciphertext content and the encrypted mapping parameters, encrypted distribution processing is performed to generate an encrypted summary. The process of encrypting the contract content based on the word frequency of the keyword set extracted from the contract content includes: extracting a keyword set from the contract content according to a preset order structure; calculating the word frequency of each keyword in the keyword set in the contract content; generating an encrypted dataset based on the word frequency; and using the encrypted dataset to encrypt the contract content.

2. The method for encrypting electronic contract content based on sequence decomposition according to claim 1, characterized in that, Generating encrypted mapping parameters includes defining the keyword offset position and the corresponding word frequency as a set of raw parameters; A mathematical mapping function is constructed based on the original parameters, and corresponding mapping parameters are generated for each set of original parameters; and the mapping parameters are encrypted.

3. The method for encrypting electronic contract content based on sequence decomposition according to claim 1, characterized in that, Based on the ciphertext content and the encrypted mapping parameters, the encrypted distribution process includes: Based on the encrypted mapping parameters, a contract offset structure that is consistent with the preset order structure is generated; using the encrypted mapping parameters as input and in combination with the contract offset structure, encrypted distribution processing is performed on the encrypted content.

4. The method for encrypting electronic contract content based on sequence decomposition according to claim 2, characterized in that, The method also includes: generating a decryption key based on mapping parameters to decrypt the ciphertext of the content; and using the decryption key to perform decryption processing on the ciphertext of the content to restore the contract content.

5. An electronic contract content encryption system based on sequence decomposition, characterized in that, The system includes: a content encryption module, used to obtain the contract content of electronic contracts and perform content encryption processing on the contract content based on the word frequency of a set of keywords extracted from the contract content, so as to generate ciphertext content; The parameter encryption module is used to generate mapping parameters based on the offset position and word frequency of keywords in the keyword set, and to encrypt the mapping parameters to generate encrypted mapping parameters. The encrypted distribution module is used to perform encrypted distribution processing based on the ciphertext content and the encrypted mapping parameters to generate an encrypted digest; And a content decryption module, which generates a decryption key based on the mapping parameters and uses the decryption key to perform decryption processing on the ciphertext content.

6. The electronic contract content encryption system based on sequence decomposition according to claim 5, characterized in that, The content encryption module is configured as follows: Extract a set of keywords from the contract content according to a pre-defined order structure; The contract content is encrypted by statistically analyzing the frequency of each keyword in the keyword set and generating an encrypted dataset based on the frequency.

7. The electronic contract content encryption system based on sequence decomposition according to claim 5, characterized in that, The parameter encryption module is configured to: define the offset position of the keyword and the corresponding word frequency as a set of raw parameters; and construct a mathematical mapping function based on the raw parameters to generate the mapping parameters; And the mapping parameters are encrypted.

8. The electronic contract content encryption system based on sequence decomposition according to claim 5, characterized in that, The encrypted distribution module is configured as follows: Based on the encrypted content and the encrypted mapping parameters, encrypted distribution processing is performed to generate an encrypted digest.

9. The electronic contract content encryption system based on sequence decomposition according to claim 8, characterized in that, The encrypted distribution module is also configured to: generate a contract offset structure that is consistent with the preset order structure based on the encrypted mapping parameters; and perform encrypted distribution processing on the ciphertext of the content by taking the encrypted mapping parameters as input and combining the contract offset structure.

10. The electronic contract content encryption system based on sequence decomposition according to claim 5, characterized in that, The content decryption module is configured to generate a decryption key for decrypting ciphertext based on the mapping parameters; And use the decryption key to decrypt the ciphertext of the content in order to restore the contract content.

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