A dual-channel symmetric data management method for a real-time network of a ship

Abstract

The application discloses a dual-channel symmetry data management method for a real-time network of a ship, and relates to the technical field of ship communication network security. The data management method is based on the optimization design of the national secret SM4 algorithm, adopts a main-backup dual-channel redundant transmission mechanism, realizes microsecond-level encryption delay by optimizing 16 rounds of fast iteration of the SM4 algorithm, adopts a dynamic key negotiation mechanism based on a timestamp and cabin coding to ensure the independence of session keys, and realizes four-level priority hierarchical encryption to guarantee high security and meet the low delay requirement of the real-time network of the ship. The application has the advantages of high real-time performance, strong reliability, good security and strong environmental adaptability, and is suitable for the real-time data transmission security protection between a ship integrated platform management system, an automatic system and shipborne equipment.

Description

Technical Field

[0001] This invention relates to a dual-channel symmetric data encryption algorithm for real-time ship networks, applicable to the security protection of real-time data transmission between Integrated Platform Management System (IPMS), ship automation system, navigation system and shipboard equipment, and belongs to the field of ship communication network security technology. Background Technology

[0002] With the continuous improvement of ship intelligence and networking, modern ships have built complex real-time communication network systems to connect various key subsystems such as navigation, power, electricity, communication, and weaponry. Ship real-time networks have special requirements such as high real-time performance, high reliability, and strong environmental adaptability. The data they transmit often involves sensitive information such as ship navigation safety, combat command, and cargo management, posing a dual challenge to data encryption security and real-time performance.

[0003] Currently, the encryption technologies used in ship network communications mainly have the following problems:

[0004] 1) Insufficient real-time performance: Traditional encryption algorithms such as AES and DES perform well on general computing platforms, but they have high computational overhead in ship embedded systems and are difficult to meet the millisecond or even microsecond transmission delay requirements of ship real-time networks.

[0005] 2) Complex key management: Ship networks have numerous nodes and dynamic topology, making it difficult for traditional key distribution and management mechanisms to adapt to the mobility and autonomy of ship networks. Summary of the Invention

[0006] The purpose of this invention is to provide a data encryption and management solution that meets the requirements of low latency in real-time ship network while also possessing high security and high reliability.

[0007] To address the aforementioned objectives, the present invention discloses a dual-channel symmetric data management method for real-time networks of ships, characterized by comprising: A primary and backup dual-channel parallel transmission mechanism is established. The primary channel and the backup channel are physically isolated and use independent data link layer and transport layer protocol stacks. The primary channel undertakes normal data transmission tasks, while the backup channel performs real-time and synchronous operation tasks. When the primary channel fails, the system automatically switches to the backup channel within microseconds to ensure communication continuity. The SM4 algorithm is optimized and designed, and a lightweight real-time encryption engine is implemented using a four-stage pipeline architecture. The 32 rounds of iteration of the SM4 algorithm are optimized into a 16-round fast iteration mode, and the computational overhead is reduced by pre-computing round keys and table lookup technology. A dynamic key generation algorithm based on timestamps and compartment coding is adopted to ensure that an independent key is used for each communication session; Ship network data is divided into four priority levels according to real-time requirements, and hardware-accelerated direct encryption, optimized SM4 algorithm software encryption, standard SM4 algorithm encryption, or asynchronous processing are adopted respectively. Forward error correction coding is added after the encrypted data to improve the transmission reliability in strong electromagnetic interference environment.

[0008] Preferably, it also includes the step of defining key distribution channels and management layers: Keys are mainly distributed periodically via USB or CD, and are registered uniformly by management. Only AES encryption allows for limited-time broadcasting on the internal network in emergency situations, after which the key can be switched directly. The key lifecycle is fully controlled, supporting dynamic rotation and immediate expiration based on navigation missions.

[0009] Preferably, in the primary and backup dual-channel parallel transmission mechanism, the primary channel and the backup channel adopt a symmetrical design. The encryption parameters, key system, and transmission protocol of the primary channel and the backup channel are completely consistent, but they are transmitted through different physical paths, which improves the system's anti-attack capability and fault tolerance capability.

[0010] Preferably, the dual-channel redundant transmission mechanism includes: the sending end simultaneously writes encrypted data into the sending queues of the main channel and the backup channel, and the MAC controllers of the main channel and the backup channel send simultaneously; the receiving end determines the freshness of the data packets by comparing timestamps, and selects the data packets that arrive first and pass the verification for decryption; the bit error rate, latency, and packet loss rate of the main channel and the backup channel are monitored in real time, and a switch is automatically triggered when the quality of the main channel deteriorates, with the switchover time controlled within 500 microseconds.

[0011] Preferably, the dynamic key generation algorithm is expressed as follows: K_session=SM4_KDF(K_master||Timestamp||Position_hash||Counter) Where K_master is the preset master key, Timestamp is the system timestamp accurate to microseconds, Position_hash is the hash value of the ship's current position, and Counter is the session counter.

[0012] Preferably, the four priority levels include Emergency, Important, Normal, and Low, with priority levels ranging from high to low.

[0013] Preferably, the Emergency level targets navigation, collision avoidance, and power control data, with a latency requirement of <1ms. It employs an optimized SM4 hardware-accelerated pass-through encrypted call to the Electronic Codebook (ECB) mode, which has a limited data length but the fastest response. The Importan class, targeting weapon systems and communication command data, requires a latency of <5ms. It employs an optimized SM4 hardware encryption call counter mode (CTR) with dual-channel synchronous transmission, one channel transmitting the key and the other channel transmitting the data. The general-level Normal is designed for monitoring and log data, with a latency requirement of <50ms, and uses the standard SM4 hardware encryption call cipher block cipher mode (CBC). The standard Low level is designed for file transfers and non-critical data, with a latency requirement of <200ms, and uses software AES encryption or asynchronous processing.

[0014] Preferably, a fast mode is used for short data packets. When the length of the data to be encrypted is less than 64 bytes, some pipeline stages are skipped and direct table lookup encryption is used, which reduces the encryption latency by 50%.

[0015] Preferably, the forward error correction coding adopts Reed-Solomon error correction code, and the receiver detects and defends against replay attacks and delay attacks by comparing the timestamp differences of the primary and backup channel data.

[0016] Preferably, it also includes steps for interference resistance and fault tolerance design, including: Retrieve the field to be encrypted from the pre-encrypted cache pool; Forward error correction coding (FEC): Reed-Solomon error correction codes are added after the encrypted data to improve transmission reliability in environments with strong electromagnetic interference and reduce retransmissions caused by bit errors. Time synchronization verification: Dual-channel data transmission contains precise timestamp information. The receiving end detects and defends against network attacks by comparing the timestamp differences between the primary and backup channel data. Channel health monitoring: Real-time monitoring of quality indicators of both channels, including bit error rate, latency, and packet loss rate. Automatic switching is triggered when the quality of the main channel deteriorates, with the switching time controlled within 500 microseconds.

[0017] The algorithm provided by this invention is based on the national cryptographic SM4 algorithm and the standard AES algorithm, optimized for real-time networks. It employs a dual-channel redundant transmission mechanism to ensure high security while meeting the stringent requirements of ship real-time networks regarding transmission latency. Compared with existing technologies, this invention offers the following advantages: 1. High real-time performance: The encrypted transmission latency is reduced to the microsecond level through SM4 algorithm optimization, meeting the stringent requirements of ship real-time control systems; 2. High reliability: The dual-channel redundant architecture, combined with a fast switching mechanism, ensures uninterrupted service in the event of a single-channel failure, with switching time controlled within 500 microseconds, significantly improving the availability of the ship's communication network; 3. High security: It adopts the national cryptographic algorithm SM4, which complies with national cryptographic management requirements; the dynamic key negotiation mechanism ensures the independence and unpredictability of session keys; and the binding of timestamps and location information prevents replay attacks. 4. Strong environmental adaptability: Forward error correction coding and anti-interference design improve transmission reliability in the harsh electromagnetic environment of ships and reduce communication failures caused by environmental factors. 5. High resource efficiency: The lightweight SM4 implementation and priority-based processing mechanism minimize computational resource overhead while ensuring security, making it suitable for resource-constrained ship embedded systems. 6. Easy to deploy: The modular and standardized design of the algorithm makes it easy to integrate into existing ship network equipment and supports smooth upgrades and expansions. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the physical architecture of a single device in the dual-channel symmetric data encryption system described in this invention. Figure 2 A schematic diagram of the minimum data interaction subsystem of a dual-channel symmetric data encryption system. Figure 3 This is a flowchart of the transmission process when the device is in ECB mode; Figure 4 This is a flowchart of the receiving process when the device is in ECB mode; Figure 5 This is a flowchart of the transmission process when the device is in CRT mode; Figure 6 This is a flowchart of the receiving process when the device is in CRT mode; Figure 7 This is a flowchart of the dynamic key negotiation process. Detailed Implementation

[0019] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0020] In this embodiment of the invention, as follows Figure 2The dual-channel symmetric data encryption system shown is deployed at various network nodes of the ship's real-time network, including but not limited to navigation computers, power control systems, power management systems, and communication equipment. Each network node contains the following core components: at least two dual-channel symmetric data transmission devices (one of which is modularly embedded in the host and can interact with the host via USB / SPI / UART, etc.), one timing server, and at least one controlled loop.

[0021] The principle of each dual-channel symmetrical data transmission device is as follows: Figure 1 As shown. Each dual-channel symmetrical data transmission device connects to the control network loop via the second network physical layer interface PHY2 and to the information network loop via the first network physical layer interface PHY1. The time synchronization server of each dual-channel symmetrical data transmission device connects to either the control network loop or the information network loop to achieve time synchronization between devices. After each dual-channel symmetrical data transmission device is connected to a 12V DC steady-state power supply, the CPU of each device starts its built-in minimum system, configures the correct IP address, subnet mask address, gateway, and time synchronization address, and begins the time synchronization function. After time synchronization is completed, subsequent data encryption and interaction commands can be executed.

[0022] Each dual-channel symmetric data transmission device's FPGA-based national cryptographic module (or key management unit) is a crucial security management and distribution module. It includes a secure memory (HSM) for storing the master key and a key derivation engine for generating session keys. The secure memory uses encryption chips compliant with national cryptographic standards and supports the full range of SM2 / SM3 / SM4 algorithms.

[0023] Each dual-channel symmetrical data transmission device obtains the current real-time clock from the ship's time synchronization satellite source based on a real-time operating system, and allocates key resources and network time slot bandwidth according to data priority to ensure that the transmission delay of high-priority data meets the requirements.

[0024] After the deployment of the dual-channel symmetric data encryption system is completed, it can realize the real-time guarantee strategy - emergency level - single-channel conventional encrypted data transmission mechanism (hereinafter referred to as "ECB"), the real-time guarantee strategy - important level - dual-channel encrypted redundant transmission mechanism (hereinafter referred to as "CTR"), the fault switching mechanism, and the dynamic key negotiation protocol (an emergency key internal distribution mechanism other than standard USB / CD distribution).

[0025] like Figure 3 As shown, the sending end processing flow in ECB mode includes the following steps: 1. Application layer data is submitted to the encryption driver via system calls; 2. The driver selects the encryption path based on data priority and determines it to be in ECB mode; 3. The SM4 encryption engine encrypts the data, generates ciphertext, and adds cabin codes and timestamps for data obfuscation; 4. Adding FEC encoding to obfuscated ciphertext data improves data transmission robustness; 5. Before outputting, determine which MAC controller queue to use for output based on feedback from the channel quality module; 6. After sending, return an acknowledgment to the application layer.

[0026] like Figure 4 As shown, the receiver processing flow in ECB mode includes the following steps: 1. The MAC controllers of Channel A and Channel B respectively receive network data; 2. The data packet undergoes integrity verification (CRC check); 3. Determine the freshness of data packets by comparing timestamps and discard replay attack data; 4. Select the first arriving and verified data packet for decryption; 5. The SM4 decryption engine recovers plaintext data; 6. Submit plaintext data to the application layer. If there is a problem, invoke the failover mechanism.

[0027] like Figure 5 As shown, the sending end processing flow in CTR mode includes the following steps: 1. Application layer data obtains the current timestamp and cabin code through system calls and submits them to the key generator; 2. The key generator generates a key based on the CTR mode command, and uses it in conjunction with timestamps and cabin target parameters to obfuscate the data; 3. The plaintext is iteratively processed according to the key to generate ciphertext, which is then obfuscated using timestamps and cabin target parameters; 4. All data streams are FEC encoded to increase anti-interference capability; 5. The dual-channel MAC controller simultaneously reads data from the queue and sends it; 6. After sending, return an acknowledgment to the application layer.

[0028] like Figure 6 As shown, the receiver processing flow in CTR mode is as follows: 1. The MAC controllers of Channel A and Channel B respectively receive network data; 2. Data packets undergo integrity verification (CRC check) and channel quality monitoring module checks; 3. After data quality inspection, the data is decoded by FEC and compared with the compartment code and data packet freshness, and invalid data is discarded; 4. SM4 uses an encryption engine to recover plaintext data based on the signaling relationship between the ciphertext and the key; 6. Submit the plaintext data to the application layer.

[0029] Failover mechanism: During the aforementioned dual-channel redundant encrypted transmission, the channel quality monitoring module (in the input buffer time slot control) continuously monitors the bit error rate, latency, and packet loss rate of both channels. If the main channel bit error rate exceeds 10... -6 If the delay exceeds a threshold, the channel is flagged as abnormal. In this case, the system automatically switches the traffic to the backup channel, meaning the dual-channel data stream is transmitted within a single channel. The data packets for Channel A and Channel B remain completely unchanged; the subsequent reception and splitting process only separates ciphertext A and ciphertext B, identifying the key / ciphertext based on the signaling markers before merging. There is no packet loss during the switching process. Once the primary channel returns to normal, automatic reverting or maintaining the current channel can be selected.

[0030] like Figure 7 As shown, the dynamic key negotiation protocol includes the following steps: Step 1: Session establishment request, specifically including: Step 101: The sender generates a 32-byte random number Nonce_S; Step 102: Calculate the timestamp T_s (microsecond-level Unix time); Step 103: Obtain the current cabin positions Lat_s and Lon_s, and calculate the position hash Pos_s = SM3(Lat_s ||Lon_s); Step 104: Construct a session request message: Req = {ID_s, T_s, Pos_s, Nonce_S}, where ID_s represents the ID that initiates the key change, and key change commands are only allowed to be initiated within a limited range of host IDs.

[0031] Step 2: Session establishment response, specifically including: Step 201: The receiver verifies whether the difference between the timestamp T_s and the local time is within the allowable range (±1 second). The receiver verifies whether the location hash Pos_s and the cabin interaction data are within a reasonable range. Step 202: Generate a 32-byte random number Nonce_R; Step 203: Calculate the session key: K_session=SM4_KDF(K_master, T_s, Pos_s, Nonce_S⊕Nonce_R), where K_master represents the preset master key package (referring to the key issued from the CD or manually entered in the early stage); Step 204: Construct the response message: Resp = {ID_r, T_r, SM4_Ksession(ID_s||Nonce_R)}, where ID_r represents the local ID of the responding party confirming participation in the change for statistical purposes, T_r represents the expected timeframe after which the responding machine will synchronize the change key, and Tr generally uses the default value, but relevant parameters can be adjusted in encrypted communication scenarios.

[0032] Step 3: Key verification, specifically including: Step 301: The sender decrypts the response message and verifies its identity; Step 302: Calculate the same session key K_session; Step 303: Send a key confirmation message: Confirm = SM4_Ksession(Nonce_R||Counter), where Counter represents the session counter; Step 304: Both parties enter encrypted communication mode.

[0033] Step 4: Key update, which includes: Step 401: Start the timer. When the key update period is reached, perform a key refresh, or trigger a key update when the data packet counter reaches a preset threshold. Step 402: The new key is transmitted encrypted using the old key, achieving a seamless switchover.

[0034] The performance of the algorithm of this invention was tested on a typical marine embedded hardware platform (ARM Quad core Cortex-A76 + Quad core Cortex-A55 + custom FPGA acceleration), and the results are shown in the table below:

[0035] Test results show that the algorithm of this invention outperforms the comparison scheme in key indicators such as encryption throughput, transmission latency, and resource consumption in a 10G dual-redundant private network, and fully meets the application requirements of ship real-time networks.

[0036] Those skilled in the art will understand that the features described in the various embodiments and / or claims of this invention can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. In particular, the features described in the various embodiments and / or claims of this invention can be combined or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.

[0037] The embodiments of the present invention have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of the present invention is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of the present invention, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A dual-channel symmetric data management method for real-time networks of ships, characterized in that, include: A primary and backup dual-channel parallel transmission mechanism is established. The primary channel and the backup channel are physically isolated and use independent data link layer and transport layer protocol stacks. The primary channel undertakes normal data transmission tasks, while the backup channel performs real-time and synchronous operation tasks. When the primary channel fails, the system automatically switches to the backup channel within microseconds to ensure communication continuity. The SM4 algorithm is optimized and designed, and a lightweight real-time encryption engine is implemented using a four-stage pipeline architecture. The 32 rounds of iteration of the SM4 algorithm are optimized into a 16-round fast iteration mode, and the computational overhead is reduced by pre-computing round keys and table lookup technology. A dynamic key generation algorithm based on timestamps and compartment coding is adopted to ensure that an independent key is used for each communication session; Ship network data is divided into four priority levels according to real-time requirements, and hardware-accelerated direct encryption, optimized SM4 algorithm software encryption, standard SM4 algorithm encryption, or asynchronous processing are adopted respectively. Forward error correction coding is added after the encrypted data to improve the transmission reliability in strong electromagnetic interference environment.

2. The dual-channel symmetric data management method for a ship's real-time network according to claim 1, characterized in that, It also includes the steps of defining key distribution channels and management layers: Keys are mainly distributed periodically via USB or CD, and are registered uniformly by management. Only AES encryption allows for limited-time broadcasting on the internal network in emergency situations, after which the key can be switched directly. The key lifecycle is fully controlled, supporting dynamic rotation and immediate expiration based on navigation missions.

3. The dual-channel symmetric data management method for a ship's real-time network according to claim 1, characterized in that, In the dual-channel parallel transmission mechanism, the primary and backup channels adopt a symmetrical design. The encryption parameters, key system, and transmission protocol of the primary and backup channels are completely identical, but they are transmitted through different physical paths, which improves the system's anti-attack capability and fault tolerance capability.

4. The dual-channel symmetric data management method for a ship's real-time network according to claim 1, characterized in that, The dual-channel redundant transmission mechanism includes: the sending end simultaneously writes encrypted data into the sending queues of the main channel and the backup channel, and the MAC controllers of the main channel and the backup channel send simultaneously; the receiving end judges the freshness of the data packets by comparing timestamps, and selects the data packets that arrive first and pass the verification for decryption; the bit error rate, latency and packet loss rate of the main channel and the backup channel are monitored in real time, and automatic switching is triggered when the quality of the main channel deteriorates, with the switching time controlled within 500 microseconds.

5. A dual-channel symmetric data management method for a ship's real-time network according to claim 1, characterized in that, The dynamic key generation algorithm is expressed as follows: K_session=SM4_KDF(K_master||Timestamp||Position_hash||Counter) Where K_master is the preset master key, Timestamp is the system timestamp accurate to microseconds, Position_hash is the hash value of the ship's current position, and Counter is the session counter.

6. A dual-channel symmetric data management method for a ship's real-time network according to claim 1, characterized in that, The four priority levels are: Emergency, Important, Normal, and Low, in descending order of priority.

7. A dual-channel symmetric data management method for a ship's real-time network according to claim 6, characterized in that, The Emergency level targets navigation, collision avoidance, and power control data, with a latency requirement of <1ms. It employs optimized SM4 hardware acceleration for direct encrypted access to the Electronic Codebook (ECB) mode, which has a limited data length but the fastest response time. The Importan class, targeting weapon systems and communication command data, requires a latency of <5ms. It employs an optimized SM4 hardware encryption call counter mode (CTR) with dual-channel synchronous transmission, one channel transmitting the key and the other channel transmitting the data. The general-level Normal is designed for monitoring and log data, with a latency requirement of <50ms, and uses the standard SM4 hardware encryption call cipher block cipher mode (CBC). The standard Low level is designed for file transfers and non-critical data, with a latency requirement of <200ms, and uses software AES encryption or asynchronous processing.

8. A dual-channel symmetric data management method for a ship's real-time network according to claim 1, characterized in that, For short data packets, a fast mode is used. When the length of the data to be encrypted is less than 64 bytes, some pipeline stages are skipped and direct table lookup encryption is used, reducing encryption latency by 50%.

9. A dual-channel symmetric data management method for a ship's real-time network according to claim 1, characterized in that, The forward error correction coding adopts Reed-Solomon error correction code. The receiver detects and defends against replay attacks and delay attacks by comparing the timestamp differences between the primary and backup channel data.

10. A dual-channel symmetric data management method for a ship's real-time network according to claim 1, characterized in that, It also includes steps for interference immunity and fault tolerance design, including: Retrieve the field to be encrypted from the pre-encrypted cache pool; Forward error correction coding (FEC): Reed-Solomon error correction codes are added after the encrypted data to improve transmission reliability in environments with strong electromagnetic interference and reduce retransmissions caused by bit errors. Time synchronization verification: Dual-channel data transmission contains precise timestamp information. The receiving end detects and defends against network attacks by comparing the timestamp differences between the primary and backup channel data. Channel health monitoring: Real-time monitoring of quality indicators of both channels, including bit error rate, latency, and packet loss rate. Automatic switching is triggered when the quality of the main channel deteriorates, with the switching time controlled within 500 microseconds.

Images