A privacy data protection method and system for resisting communication anomalies

Abstract

The present invention belongs to the field of confidential communication technology, and discloses a privacy data protection method and system for resisting communication anomalies, wherein the method is as follows: both parties complete the sharing and backup of symmetric keys; both communicating parties randomly select the backed-up symmetric keys for data encryption transmission; when communication is interrupted, the sender uses the backed-up symmetric key before the interruption to encrypt the symmetric key generated after the interruption, and uses the symmetric key after the interruption to encrypt the data; after communication is restored, the sender sends the encryption result, and the other party uses the symmetric key before the interruption to decrypt the symmetric key after the interruption, and uses the symmetric key generated after the interruption to decrypt the data, and restore normal communication. Compared with the prior art, the present invention ensures a high degree of communication security, and when communication is interrupted, the sender can safely generate and store encrypted data. Due to the high difficulty of dynamic key update and decryption, the key security of the sender is greatly improved, ensuring the security and reliability of the entire communication process.

Description

Technical Field

[0001] The present invention relates to the field of confidential communication technology, and in particular to a privacy data protection method and system for resisting communication anomalies. Background Art

[0002] With the development of information technology, both parties in the communication process are facing more and more security threats. Especially in the process of data transmission, how to ensure the confidentiality and integrity of data and prevent third-party eavesdropping and tampering has become an important research topic. Although traditional symmetric encryption algorithms can guarantee data security to a certain extent, in a complex communication environment, a single symmetric key is difficult to cope with the growing security threats. Especially when the two parties communicate frequently, the efficiency and security of key management and update are particularly important.

[0003] At present, in the existing technical solutions, fixed symmetric keys are usually used to encrypt communication data. However, when the symmetric key remains unchanged for a long time, once the key is leaked, the entire communication process will be exposed to risks. In order to solve this problem, the dynamic key update mechanism has become an effective means. By updating the key regularly or irregularly, the security of the communication process can be significantly improved. In addition, with the widespread application of IoT devices and mobile terminals, how to securely store and transmit sensitive data when the front end cannot communicate with the back end in real time is also an important challenge.

[0004] Existing technical solutions still have some deficiencies in key update, management, and data protection in offline environments. Therefore, a new communication system and method is urgently needed to improve the data transmission security between the communicating parties by dynamically updating the symmetric key and combining the security management mechanism of offline data, and ensure that sensitive data transmission is also highly secure when communication is interrupted. Summary of the invention

[0005] In view of the above defects in the prior art, the present invention proposes a privacy data protection method and system for resisting communication anomalies.

[0006] The technical solution of the present invention is achieved in this way:

[0007] A privacy data protection method for resisting communication anomalies, the method comprising the following steps:

[0008] 1) Communication preparation: The two communicating parties share a preset key in advance and use the preset key to complete the first generation, sharing and backup of the symmetric key;

[0009] 2) Normal communication: The two communicating parties randomly select the backed-up symmetric key for data encryption transmission, and each time the two parties communicate, they will generate a new symmetric key and share and back it up;

[0010] 3) Abnormal protection: When the communication is interrupted, the party with the data to be sent uses the symmetric key backed up before the interruption to encrypt the symmetric key generated after the interruption, and uses the symmetric key generated after the interruption to encrypt the data to obtain the encryption result;

[0011] 4) Communication recovery: After communication is restored, the sender sends the encryption result, and the receiver uses the symmetric key backed up before the interruption to decrypt the symmetric key generated after the interruption, and uses the symmetric key generated after the interruption to decrypt the encryption result and restore normal communication.

[0012] Preferably, in the communication preparation stage, both communicating parties simultaneously generate a key identifier corresponding to the symmetric key, and share and back up the key identifier.

[0013] For the initial communication in the normal communication phase, the steps for the communicating parties to randomly select the backed-up symmetric key include:

[0014] 1) The receiver randomly selects a backed-up key identifier and can find the corresponding symmetric key through the key identifier;

[0015] 2) The receiver uses the preset key to encrypt the selected key identifier and sends the encrypted result to the sender;

[0016] 3) The sender uses the preset key to decrypt the key identifier and finds the corresponding symmetric key through the key identifier;

[0017] For subsequent communications in the normal communication phase, the steps for the communicating parties to select a random symmetric key include:

[0018] 1) The receiver randomly selects a backed-up key identifier and can find the corresponding symmetric key through the key identifier;

[0019] 2) The receiver encrypts the key identifier selected this time with the symmetric key randomly selected last time, and sends the encrypted result to the sender;

[0020] 3) The sender decrypts the key identifier selected this time with the symmetric key randomly selected last time, and finds the corresponding symmetric key through the key identifier selected this time.

[0021] Preferably, in the communication preparation stage:

[0022] 1) The two communicating parties share a preset key before the initial communication;

[0023] 2) The receiver generates a symmetric key, encrypts it with a preset key, and sends it to the sender, who decrypts it to obtain the symmetric key.

[0024] Normal communication phase:

[0025] 1) The receiver generates a new symmetric key, encrypts it with the last randomly selected symmetric key, and sends it to the sender. The sender decrypts it with the last randomly selected symmetric key to obtain the new key.

[0026] Preferably, the backup of the symmetric key is as follows: after the symmetric key of one party is generated, both communicating parties store it in their own independent backup devices or secure areas.

[0027] Preferably, in the abnormal protection stage, the selection method of the symmetric key that has been backed up before the interruption includes:

[0028] 1) The sender with data to be sent randomly selects one from the key identifiers that were backed up before the interruption, and uses the key identifier to find the corresponding symmetric key that was backed up before the interruption;

[0029] 2) The sender searches for the corresponding symmetric key through the key identifier randomly selected last time, uses the symmetric key to encrypt the key identifier selected this time, and saves the encrypted result;

[0030] In the communication recovery phase, the specific manner in which the sender sends the encryption result and the receiver receives the encryption result is:

[0031] The sender sends the encryption results and the corresponding serial numbers of the encryption results to the receiver in the order in which the encryption results are generated. After receiving the encryption results, the receiver processes the encryption results in ascending order of the serial numbers, searches for the corresponding symmetric key through the key identifier randomly selected last time, uses the symmetric key to decrypt, obtains the key identifier randomly selected this time by the party that stores the data to be sent, and uses the key identifier to find the symmetric key that was backed up before the interruption.

[0032] Preferably, the communication interruption in the abnormal protection stage includes the case where the communication is disconnected due to external factors and the case where both parties of communication actively disconnect the communication.

[0033] Preferably, when the sender and the receiver are unable to communicate, one party verifies the communication status with the other party before randomly selecting a key identifier, and the verification includes but is not limited to detecting the status of the communication connection and the communication delay time; when the party detects that the communication connection is normal but still cannot communicate with the other party, it randomly selects one from the backed up key identifiers and executes subsequent processes.

[0034] The present invention also discloses a privacy data protection system for resisting communication anomalies, comprising:

[0035] Symmetric key pool: used to generate, share and store symmetric keys;

[0036] Key identifier generation and management module: used to synchronously generate the corresponding key identifier when generating the symmetric key, and share and back up the key identifier in the communication preparation stage;

[0037] Communication module: used for normal communication, abnormal protection and communication recovery;

[0038] Encryption module: used to encrypt data during normal communication and communication interruption;

[0039] Decryption module: used to decrypt the received encrypted information;

[0040] Storage module: used to securely store the generated symmetric keys and key identifiers locally.

[0041] Preferably, the system application process:

[0042] 1) Communication preparation stage: The communicating parties complete the generation, sharing and backup of symmetric keys through the symmetric key pool. The key identifier generation and management module generates the corresponding key identifier and shares and backs it up. The two parties use the preset key to generate and encrypt the symmetric key during the initial communication. In the subsequent communication, the two parties encrypt the newly generated key with the symmetric key generated last time and transmit it;

[0043] 2) Normal communication stage: The communicating parties randomly select a backed-up key identifier, use the key identifier to find the corresponding symmetric key, and use the encryption module to encrypt and transmit the selected key identifier using the current key. The receiving party decrypts the selected key identifier through the decryption module and uses the key identifier to find the corresponding symmetric key to decrypt the data;

[0044] 3) Abnormal protection stage: When the communication is interrupted, the party with the data to be sent randomly selects one from the key identifiers that have been backed up before the interruption, obtains the corresponding symmetric key by searching the key identifier, uses the symmetric key to encrypt the symmetric key generated after the interruption, and uses the symmetric key generated after the interruption to encrypt the data. The encryption result is saved by the encryption module;

[0045] 4) Communication recovery phase: After communication is restored, the sender sends the encryption result and its corresponding serial number to the receiver in the order in which the encryption result is generated. The receiver uses the symmetric key before the interruption to decrypt the selected key identifier through the decryption module in sequence, obtains the corresponding symmetric key and decrypts the encrypted data, and restores normal communication;

[0046] 5) Support for abnormal communication types: The system supports communication interruptions caused by external factors or active disconnection by both communicating parties. In this case, communication security can still be guaranteed and the backed-up keys can continue to be used for protection.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] The present invention provides a privacy data protection method and system for resisting communication anomalies. The sender generates its own symmetric key after decrypting the key, ensuring the security of two-way communication. In particular, in the event of communication interruption, the sender can still generate and store encrypted data, further ensuring data security. The dynamic switching and pre-generation mechanism of the key speeds up the key exchange process and reduces communication delays, especially in high-frequency communication scenarios, significantly improving the response speed and overall performance of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 A process diagram of the privacy data protection method for resisting communication anomalies of the present invention;

[0050] Figure 2 This is a process diagram of a privacy data protection method for the entire communication process between two communicating parties in the first embodiment of the present invention;

[0051] Figure 3 This is a system block diagram of Embodiment 2 of the privacy data protection system for resisting communication anomalies of the present invention. DETAILED DESCRIPTION

[0052] The present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0053] like Figure 1 As shown, a privacy data protection method for resisting communication anomalies of the present invention comprises the following steps:

[0054] 1) Communication preparation: The two communicating parties share a preset key in advance and use the preset key to complete the first generation, sharing and backup of the symmetric key;

[0055] 2) Normal communication: The two communicating parties randomly select the backed-up symmetric key for data encryption transmission, and each time the two parties communicate, they will generate a new symmetric key and share and back it up;

[0056] 3) Abnormal protection: When the communication is interrupted, the party with the data to be sent uses the symmetric key backed up before the interruption to encrypt the symmetric key generated after the interruption, and uses the symmetric key generated after the interruption to encrypt the data to obtain the encryption result;

[0057] 4) Communication recovery: After communication is restored, the sender sends the encryption result, and the receiver uses the symmetric key backed up before the interruption to decrypt the symmetric key generated after the interruption, and uses the symmetric key generated after the interruption to decrypt the encryption result and restore normal communication.

[0058] In the communication preparation phase, both parties simultaneously generate a key identifier corresponding to the symmetric key, share and back up the key identifier, and use the key identifier to find the corresponding symmetric key through a search function.

[0059] For the initial communication in the normal communication phase, the steps for the communicating parties to randomly select the backed-up symmetric key include:

[0060] 1) The receiver randomly selects a backed-up key identifier and can find the corresponding symmetric key through the key identifier;

[0061] 2) The receiver uses the preset key to encrypt the selected key identifier and sends the encrypted result to the sender;

[0062] 3) The sender uses the preset key to decrypt the key identifier and finds the corresponding symmetric key through the key identifier;

[0063] For subsequent communications in the normal communication phase, the steps for the communicating parties to select a random symmetric key include:

[0064] 1) The receiver randomly selects a backed-up key identifier and can find the corresponding symmetric key through the key identifier;

[0065] 2) The receiver encrypts the key identifier selected this time with the symmetric key randomly selected last time, and sends the encrypted result to the sender;

[0066] 3) The sender decrypts the key identifier selected this time with the symmetric key randomly selected last time, and finds the corresponding symmetric key through the key identifier selected this time.

[0067] The method for two communicating parties to pre-share a preset key and a symmetric key comprises the following steps:

[0068] 1) The two communicating parties share a preset key before the initial communication;

[0069] 2) During the initial communication, the receiver generates a symmetric key, encrypts it with a preset key and sends it to the other party. The sender obtains the symmetric key after decryption;

[0070] 3) In subsequent communications, the receiver generates a new symmetric key, encrypts the newly generated symmetric key with the last randomly selected symmetric key, and sends it to the sender. The sender uses the last randomly selected symmetric key to decrypt and obtain the new key.

[0071] The backup of the symmetric key is as follows: after one party's symmetric key is generated, both communicating parties store it in their own independent backup devices or secure areas.

[0072] In the abnormal protection stage, the selection methods of the symmetric key that has been backed up before the interruption include:

[0073] 1) The sender with data to be sent randomly selects one from the key identifiers that were backed up before the interruption, and uses the key identifier to find the corresponding symmetric key that was backed up before the interruption;

[0074] 2) The sender searches for the corresponding symmetric key through the key identifier randomly selected last time, uses the symmetric key to encrypt the key identifier selected this time, and saves the encrypted result;

[0075] In the communication recovery phase, the specific manner in which the sender sends the encryption result and the receiver receives the encryption result is:

[0076] The sender sends the encryption results and the corresponding serial numbers of the encryption results to the receiver in the order in which the encryption results are generated. After receiving the encryption results, the receiver processes the encryption results in ascending order of the serial numbers, searches for the corresponding symmetric key through the key identifier randomly selected last time, uses the symmetric key to decrypt, obtains the key identifier randomly selected this time by the party that stores the data to be sent, and uses the key identifier to find the symmetric key that was backed up before the interruption.

[0077] The communication interruption in the abnormal protection stage includes the case where the communication is disconnected due to external factors and the case where the communicating parties actively disconnect the communication.

[0078] When the sender and the receiver are unable to communicate, one party verifies the communication status with the other party before randomly selecting a key identifier, and the verification includes detecting the status of the communication connection and the communication delay time; when the one party detects that the communication connection is normal but still cannot communicate with the other party, it randomly selects one from the backed up key identifiers and executes the subsequent process.

[0079] Embodiment 1 of the present invention:

[0080] like Figure 2 As shown, a privacy data protection method for resisting communication anomalies includes a receiver A and a sender B, and the method includes the following steps:

[0081] Communication preparation and normal communication phase:

[0082] Initial communication:

[0083] 1) A and B pre-share a preset key K0;

[0084] 2) When A and B communicate for the first time, B initiates a connection request to A, and then A generates a new symmetric key KS and a corresponding key identifier M. KS is stored in the symmetric key set S. A In the example, M is stored in the key identifier set S AF middle;

[0085] 3) A from S AFA key identifier m is randomly selected, and the key identifier m corresponds to the symmetric key ks = get(m);

[0086] 4) A uses K0 to encrypt KS, M and m, and sends the encryption result to B;

[0087] 5) B receives the encryption result, decrypts it using K0, and saves KS to the symmetric key set S B , save the corresponding key identifier M to the key identifier set S BF And record the m randomly selected by end A;

[0088] 6) B generates a new symmetric key KT and a corresponding key identifier N, and saves KT to S B , N save to S BF ;

[0089] 7) B from S BF A key identifier n is randomly selected, and KT, N, n and data Data are encrypted using ks = get(m);

[0090] 8) B sends the encryption result to A, A decrypts the encryption result using ks = get(m) and saves KT to S A , N save to S AF , and record n.

[0091] Follow-up communication:

[0092] 9) In subsequent communications between A and B, A uses the last randomly selected m to find its corresponding symmetric key ks = get(m), and then generates a new symmetric key KS' and the corresponding key identifier M' and saves them to S respectively. A and S AF middle;

[0093] 10) A from S AF Randomly select an m', use ks = get(m) to encrypt KS', M' and m', and send the encrypted result to B;

[0094] 11) B uses the last randomly selected m to find the corresponding ks = get(m), decrypts the encrypted result using ks = get(m), and saves KS' to S B , M' is saved to S BF , and record the m' randomly selected by end A;

[0095] 12) B generates a new symmetric key KT' and a corresponding key identifier N', and KT' is stored in the symmetric key set S B In the example, N' is stored in the key identifier set S BF middle;

[0096] 13) B from S BF A key identifier n' is randomly selected, KT', N', n' and data Data are encrypted using ks = get(m), and the encrypted result is sent to A;

[0097] 14) A uses KS' to decrypt the encrypted result and saves KT' to S A , save N' to S AF , and record n'.

[0098] Abnormal protection stage:

[0099] 15) When B needs to transmit data confidentially but cannot communicate with A, B generates a new symmetric key KT'';

[0100] 16) B randomly selects a key identifier n'' from the backed-up key identifier set, and uses the last randomly selected key identifier n to find its corresponding symmetric key ks = get(n);

[0101] 17) B uses ks = get(n) to encrypt the newly generated KT'' and the randomly selected key identifier n'', uses KT'' to encrypt the data that needs to be transmitted confidentially, and temporarily stores the encryption result;

[0102] Communication recovery phase:

[0103] 18) When the communication between A and B is restored, B sends the encryption results and the corresponding encryption result serial numbers to A in the order in which the encryption results were generated;

[0104] 19) A uses the key identifier n randomly selected by B last time to find the corresponding symmetric key ks = get(n), and uses the symmetric key to decrypt and obtain KT'', n'';

[0105] 20) A uses KT'' to decrypt the corresponding ciphertext, obtains the data sent by the other party, and resumes normal communication.

[0106] Through the above steps, A and B can ensure the security of data transmission during communication interruption or recovery, and resist the risk of communication anomalies.

[0107] The present invention also discloses a privacy data protection system for resisting communication anomalies, comprising:

[0108] Symmetric key pool: used to generate, share and store symmetric keys;

[0109] Key identifier generation and management module: used to synchronously generate the corresponding key identifier when generating the symmetric key, and share and back up the key identifier in the communication preparation stage;

[0110] Communication module: used for normal communication, abnormal protection and communication recovery;

[0111] Encryption module: used to encrypt data during normal communication and communication interruption;

[0112] Decryption module: used to decrypt the received encrypted information;

[0113] Storage module: used to securely store the generated symmetric keys and key identifiers locally.

[0114] The system application process:

[0115] 1) Communication preparation stage: The communicating parties complete the generation, sharing and backup of symmetric keys through the symmetric key pool. The key identifier generation and management module generates the corresponding key identifier and shares and backs it up. The two parties use the preset key to generate and encrypt the symmetric key during the initial communication. In the subsequent communication, the two parties encrypt the newly generated key with the symmetric key generated last time and transmit it;

[0116] 2) Normal communication stage: The communicating parties randomly select a backed-up key identifier, use the key identifier to find the corresponding symmetric key, and use the encryption module to encrypt and transmit the selected key identifier using the current key. The receiving party decrypts the selected key identifier through the decryption module and uses the key identifier to find the corresponding symmetric key to decrypt the data;

[0117] 3) Abnormal protection stage: When the communication is interrupted, the party with the data to be sent randomly selects one from the key identifiers that have been backed up before the interruption, obtains the corresponding symmetric key by searching the key identifier, uses the symmetric key to encrypt the symmetric key generated after the interruption, and uses the symmetric key generated after the interruption to encrypt the data. The encryption result is saved by the encryption module;

[0118] 4) Communication recovery phase: After communication is restored, the sender sends the encryption result and its corresponding serial number to the receiver in the order in which the encryption result is generated. The receiver uses the symmetric key before the interruption to decrypt the selected key identifier through the decryption module in sequence, obtains the corresponding symmetric key and decrypts the encrypted data, and restores normal communication;

[0119] 5) Support for abnormal communication types: The system supports communication interruptions caused by external factors or active disconnection by both communicating parties. In this case, communication security can still be guaranteed and the backed-up keys can continue to be used for protection.

[0120] Embodiment 2 of the present invention:

[0121] like Figure 3 As shown, a privacy data protection system for resisting communication anomalies is provided, and the system comprises:

[0122] 1) Symmetric key pools SA and SB: used to generate, share and store symmetric keys;

[0123] 2) Key identifier generation and management modules MA, MB: used to synchronously generate corresponding key identifiers when generating symmetric keys, and share and back up the key identifiers in the communication preparation stage;

[0124] 3) Communication modules TA and TB: used for normal communication, abnormal protection and communication recovery;

[0125] 4) Encryption modules EA and EB: used to encrypt data during normal communication and communication interruption;

[0126] 5) Decryption modules DA and DB: used to decrypt the received encrypted information;

[0127] 6) Storage modules BA and BB: used to securely store the generated symmetric keys and key identifiers locally.

[0128] The operation steps include:

[0129] 1) Communication preparation stage: The communicating parties complete the generation, sharing and backup of symmetric keys through the symmetric key pool. The key identifier generation and management module generates the corresponding key identifier and shares and backs it up. The two parties use the preset key K0 to generate and encrypt the symmetric key during the initial communication. In subsequent communications, the two parties encrypt the newly generated key with the symmetric key generated last time and transmit it.

[0130] 2) Normal communication phase: The communicating parties randomly select a backed-up key identifier, use the key identifier to find the corresponding symmetric key, and use the encryption module to encrypt and transmit the selected key identifier using the current key. The receiver decrypts the selected key identifier through the decryption module and uses the key identifier to find the corresponding symmetric key to decrypt the data.

[0131] 3) Abnormal protection stage: When the communication is interrupted, the party with the data to be sent randomly selects a key identifier from the key identifiers that have been backed up before the interruption, obtains the corresponding symmetric key by searching the key identifier, uses the key to encrypt the symmetric key generated after the interruption, and uses the symmetric key after the interruption to encrypt the data. The encryption result is saved by the encryption module.

[0132] 4) Communication recovery phase: After communication is restored, the sender sends the encryption result and its corresponding serial number to the receiver in the order in which the encryption results are generated. The receiver uses the symmetric key before the interruption to decrypt the selected key identifier through the decryption module in sequence, obtains the corresponding symmetric key and decrypts the encrypted data, and resumes normal communication.

[0133] 5) Support for abnormal communication types: The system supports communication interruptions caused by external factors or active disconnection by both communicating parties. In this case, communication security can still be guaranteed and the backed-up keys can continue to be used for protection.

[0134] From the embodiments of the present invention, it can be seen that the present invention is a privacy data protection method and system for resisting communication anomalies. The sender generates its own symmetric key after decrypting the key, thereby ensuring the security of two-way communication. In particular, in the case of communication interruption, the sender can still generate and store encrypted data, further ensuring data security; the dynamic switching and pre-generation mechanism of the key speeds up the key exchange process and reduces communication delays, especially in high-frequency communication scenarios, significantly improving the response speed and overall performance of the system.

Claims

1. A privacy data protection method against communication anomalies, characterized in that: The method comprises the following steps: 1) Communication preparation: The two communicating parties share a preset key in advance and use the preset key to complete the first generation, sharing and backup of the symmetric key; 2) Normal communication: The two communicating parties randomly select the backed-up symmetric key for data encryption transmission, and each time the two parties communicate, they will generate a new symmetric key and share and back it up; 3) Abnormal protection: When the communication is interrupted, the party with the data to be sent uses the symmetric key backed up before the interruption to encrypt the symmetric key generated after the interruption, and uses the symmetric key generated after the interruption to encrypt the data to obtain the encryption result; 4) Communication recovery: After communication is restored, the sender sends the encryption result, and the receiver uses the symmetric key backed up before the interruption to decrypt the symmetric key generated after the interruption, and uses the symmetric key generated after the interruption to decrypt the encryption result and restore normal communication.

2. The privacy data protection method against communication anomalies according to claim 1, characterized in that: When both parties generate a symmetric key, they also generate a key identifier corresponding to the symmetric key, and share and back up the key identifier. For the initial communication in the normal communication phase, the steps for the communicating parties to randomly select the backed-up symmetric key include: 1) The receiver randomly selects a backed-up key identifier and can find the corresponding symmetric key through the key identifier; 2) The receiver uses the preset key to encrypt the selected key identifier and sends the encrypted result to the sender; 3) The sender uses the preset key to decrypt the key identifier and finds the corresponding symmetric key through the key identifier; For subsequent communications in the normal communication phase, the steps for the communicating parties to select a random symmetric key include: 1) The receiver randomly selects a backed-up key identifier and can find the corresponding symmetric key through the key identifier; 2) The receiver encrypts the key identifier selected this time with the symmetric key randomly selected last time, and sends the encrypted result to the sender; 3) The sender decrypts the key identifier selected this time with the symmetric key randomly selected last time, and finds the corresponding symmetric key through the key identifier selected this time.

3. The privacy data protection method against communication anomalies according to claim 1, characterized in that: Communication preparation stage: 1) The two communicating parties share a preset key before the initial communication; 2) The receiver generates a symmetric key, encrypts it with a preset key, and sends it to the sender, who decrypts it to obtain the symmetric key. Normal communication phase: 1) The receiver generates a new symmetric key, encrypts it with the last randomly selected symmetric key, and sends it to the sender. The sender decrypts it with the last randomly selected symmetric key to obtain the new key.

4. The privacy data protection method against communication anomalies according to claim 3 is characterized in that: The backup of the symmetric key is as follows: after one party's symmetric key is generated, both communicating parties store it in their own independent backup devices or secure areas.

5. The privacy data protection method against communication anomalies according to claim 2, characterized in that: In the abnormal protection stage, the selection methods of the symmetric key that has been backed up before the interruption include: 1) The sender with data to be sent randomly selects one from the key identifiers that have been backed up before the interruption, and uses the key identifier to find the corresponding symmetric key that has been backed up before the interruption; 2) The sender searches for the corresponding symmetric key through the key identifier randomly selected last time, uses the symmetric key to encrypt the key identifier selected this time, and saves the encrypted result; In the communication recovery phase, the specific manner in which the sender sends the encryption result and the receiver receives the encryption result is: The sender sends the encryption results and the corresponding serial numbers of the encryption results to the receiver in the order in which the encryption results are generated. After receiving the encryption results, the receiver processes the encryption results in ascending order of the serial numbers, searches for the corresponding symmetric key through the key identifier, decrypts using the symmetric key, obtains the key identifier randomly selected by the party storing the data to be sent, and searches for the symmetric key that was backed up before the interruption through the key identifier.

6. The privacy data protection method against communication anomalies according to claim 1, characterized in that: The communication interruption in the abnormal protection stage includes the case where the communication is disconnected due to external factors and the case where the communicating parties actively disconnect the communication.

7. The privacy data protection method against communication anomalies according to claim 2, characterized in that: When the sender and the receiver are unable to communicate, one party verifies the communication status with the other party before randomly selecting a key identifier, and the verification includes detecting the status of the communication connection and the communication delay time; when the one party detects that the communication connection is normal but still cannot communicate with the other party, it randomly selects one from the backed up key identifiers and executes the subsequent process.

8. A privacy data protection system for resisting communication anomalies, characterized in that: include: Symmetric key pool: used to generate, share and store symmetric keys; Key identifier generation and management module: used to synchronously generate the corresponding key identifier when generating the symmetric key, and share and back up the key identifier in the communication preparation stage; Communication module: used for normal communication, abnormal protection and communication recovery; Encryption module: used to encrypt data during normal communication and communication interruption; Decryption module: used to decrypt the received encrypted information; Storage module: used to securely store the generated symmetric keys and key identifiers locally. The system application process: 1) Communication preparation stage: The communicating parties complete the generation, sharing and backup of symmetric keys through the symmetric key pool. The key identifier generation and management module generates the corresponding key identifier and shares and backs it up. The two parties use the preset key to generate and encrypt the symmetric key during the initial communication. In the subsequent communication, the two parties encrypt the newly generated key with the symmetric key generated last time and transmit it; 2) Normal communication stage: The communicating parties randomly select a backed-up key identifier, use the key identifier to find the corresponding symmetric key, and use the encryption module to encrypt and transmit the selected key identifier using the current key. The receiving party decrypts the selected key identifier through the decryption module and uses the key identifier to find the corresponding symmetric key to decrypt the data; 3) Abnormal protection stage: When the communication is interrupted, the party with the data to be sent randomly selects one from the key identifiers that have been backed up before the interruption, obtains the corresponding symmetric key by searching the key identifier, uses the symmetric key to encrypt the symmetric key generated after the interruption, and uses the symmetric key generated after the interruption to encrypt the data. The encryption result is saved by the encryption module; 4) Communication recovery phase: After communication is restored, the sender sends the encryption result and its corresponding serial number to the receiver in the order in which the encryption result is generated. The receiver uses the symmetric key before the interruption to decrypt the selected key identifier through the decryption module in sequence, obtains the corresponding symmetric key and decrypts the encrypted data, and restores normal communication; 5) Support for abnormal communication types: The system supports communication interruptions caused by external factors or active disconnection by both communicating parties. In this case, communication security can still be guaranteed and the backed-up keys can continue to be used for protection.

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