Airborne network security protection method based on security gateway

Abstract

The invention discloses an airborne network security protection method based on a security gateway, which comprises the following steps: before network data transmission, sending a communication request message to the security gateway by an open domain, after the security gateway receives the communication request message, selecting a group of public keys and private keys from an RSA key configuration table by using a random number algorithm, the security gateway replies a communication response message containing a public key to the open domain, the open domain carries out RSA + DES encryption on the network data according to the public key, the security gateway carries out RSA + DES decryption after receiving the network data, and if the decryption is successful, the network data is transmitted to the aircraft control domain. According to the method, the session key of the DES and the public key / key of the RSA both adopt a random number generation method, and the keys in each communication process are different, so that the attack of hackers can be effectively blocked, and the safety of an airborne network, an airborne system and an airplane is ensured.

Description

Technical Field

[0001] The present invention belongs to the field of airborne network information security of civil aircraft, and particularly relates to the security protection problem of airborne ARINC664 (avionics full-duplex switched Ethernet) network. Through an airborne network security protection method based on a security gateway, it is ensured that the airborne ARINC664 network is not attacked by hackers, thereby ensuring the safety of the aircraft. Background Art

[0002] The onboard network of traditional aircraft is a closed network, which is completely physically isolated from the outside world. The outside world cannot access the onboard network, and there is no intrusion attack path, so the onboard network is very safe. However, the maintenance and operation efficiency of traditional aircraft that are completely isolated from external systems is very low, and they are increasingly unable to adapt to the requirements of informatization. The new generation of civil aircraft will be designed as a node in the information network, which can communicate and interact with ground systems for big data to meet the requirements of efficient operation and rapid maintenance. Figure 1 As shown:

[0003] 1. The aircraft control domain is the area that controls the safe flight of the aircraft. If it is attacked, it will affect flight safety, and in the worst case, it will cause the aircraft to be destroyed and people to die;

[0004] 2. The role of the information service domain is to provide interconnection between the aircraft control domain and the open domain, so that the "ground maintenance system" can access the airborne system in the aircraft control domain to achieve the purpose of rapid aircraft maintenance;

[0005] 3. The "gateway" of the information service domain realizes the conversion between "Ethernet / Wifi" and "ARINC664 / ARINC429" network protocols;

[0006] 4. The "network switch" in the aircraft control domain implements the forwarding of ARINC664 data frames of the airborne system, and one of its ports is interconnected with the "gateway" in the information service domain;

[0007] 5. The "remote data interface unit" of the aircraft control domain realizes the conversion between ARINC429 and ARINC664 network protocols.

[0008] However, under the open network interconnection architecture of aircraft, there are many kinds of security threats from the ground, such as hacker attacks, virus infections, information loss, etc. Hackers can launch attacks on the aircraft's onboard systems through the "gateway" of the information service domain and the "network switch" of the aircraft control domain, such as Figure 2 As shown, at the very least, it can destroy the onboard system data, and at worst, it can control the aircraft and threaten the safety of the aircraft and the lives of passengers. Summary of the invention

[0009] The purpose of the present invention is to provide an airborne network security protection method based on a security gateway to solve the security threat problem that the open network interconnection architecture of the aircraft may face.

[0010] The object of the present invention is achieved through the following technical solutions:

[0011] An airborne network security protection method based on a security gateway comprises the following steps:

[0012] Step 1: Configure an RSA key configuration table on the security gateway;

[0013] Step 2: The open domain sends a communication request message to the security gateway. After receiving the communication request message, the security gateway uses a random number algorithm to select a set of public keys and private keys from the RSA key configuration table, recorded as "public key GY" and "private key SY". Then the security gateway replies a communication response message to the open domain, which contains the "public key GY" information.

[0014] Step 3: After the open domain receives the communication response message from the security gateway, it takes out the "public key GY" to encrypt the network data to be sent. The steps are as follows:

[0015] Step 31) Generate a 64-bit "session key K" using a random number algorithm;

[0016] Step 32) The network data to be transmitted is grouped as "plain text M" by 8 bytes, and the ones less than 8 bytes are padded with 0;

[0017] Step 33) Combine the "plain text M" and the "session key K" and generate a "CRC32 check code A" through the CRC32 algorithm;

[0018] Step 34) Use the "session key K" to perform DES encryption on each plaintext packet to generate "ciphertext C";

[0019] Step 35) Use the "public key GY" to perform RSA encryption on the "session key K" to form an encrypted "session key EK";

[0020] Step 36) synthesize the "ciphertext C", "session key EK" and "CRC32 check code A" to generate a network message "C&EK" for transmission;

[0021] Step 37) The open domain sends the network message "C&EK" to the security gateway;

[0022] Step 4: After receiving the network message "C&EK" sent by the open domain, the security gateway performs decryption verification. If the verification is successful, the network data is converted to a protocol and then sent to the network switch to enter the aircraft control domain. Otherwise, the network data is considered unauthorized and will be directly discarded. Among them, the security gateway performs the following steps to decrypt and verify the network message "C&EK":

[0023] Step 41) Decompose the received network message "C&EK" to obtain "ciphertext C", "session key EK", and "CRC32 check code A";

[0024] Step 42) Use the "private key SY" to perform RSA decryption on the "session key EK" to obtain the "session key K";

[0025] Step 43) Use the "session key K" to perform DES decryption on the "ciphertext C" to obtain the "plaintext M";

[0026] Step 44) Combine "plain text M" and "session key K" to perform CRC32 calculation to obtain "CRC32 check code B";

[0027] Step 45) Compare "CRC32 check code A" and "CRC32 check code B" to see if they are consistent. If they are inconsistent, discard the entire network message "C&EK";

[0028] Step 46) If the CRC32 check code A is consistent with the CRC32 check code B, the security gateway performs protocol conversion on the "plain text M", packages it into an ARINC664 data frame, and sends it to the network switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of the open network interconnection architecture for aircraft;

[0030] Figure 2 This is a schematic diagram of the hacker attack path;

[0031] Figure 3 This is a schematic diagram of a security gateway;

[0032] Figure 4 It is a schematic diagram of plaintext grouping;

[0033] Figure 5 Schematic diagram of generating CRC32 checksum for ground maintenance system;

[0034] Figure 6 This is a schematic diagram of DES encryption;

[0035] Figure 7 This is a schematic diagram of RSA public key encryption;

[0036] Figure 8This is the format diagram of the network message "C&EK";

[0037] Fig. 9 Flowchart for data encryption;

[0038] Fig.10 This is a schematic diagram for RSA private key decryption;

[0039] Fig.11 This is a schematic diagram of DES decryption;

[0040] Fig.12 Calculate CRC32 checksum for security gateway;

[0041] Fig.13 Flowchart for data decryption at the security gateway;

[0042] Fig.14 Schematic diagram of the safety protection mechanism effect. DETAILED DESCRIPTION

[0043] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

[0044] The present embodiment shows an airborne network security protection method based on a security gateway, which adds a security protection mechanism to the "gateway" of the information service domain, filters out unauthorized network data, and turns the "gateway" into a "security gateway", such as Figure 3 shown.

[0045] The security protection mechanism in the security gateway uses encryption and decryption algorithms. The specific mechanism is:

[0046] 1. For open domain network data that meets the encryption algorithm requirements, it is allowed to enter the "aircraft control domain" to ensure normal communication between the open domain network (such as ground maintenance system) and the airborne system;

[0047] 2. Open domain network data that does not meet the encryption algorithm requirements will be discarded directly to prevent hacker attacks.

[0048] The encryption algorithm specifically uses DES and RSA dual encryption. The characteristics of DES and RSA encryption algorithms are as follows:

[0049] DES advantages: high encryption efficiency, fast speed, and can encrypt large blocks of data;

[0050] Disadvantages of DES: The same key is used for encryption and decryption, which results in low security.

[0051] RSA advantages: It has two keys, "public key" and "private key". The "public key" is used for encryption and the "private key" is used for decryption. It is highly secure and not easy to be cracked.

[0052] RSA disadvantages: low encryption efficiency, suitable for encryption of small blocks of data.

[0053] This embodiment combines the advantages and disadvantages of the DES and RSA encryption algorithms and adopts the DES+RSA double encryption method.

[0054] The present invention is implemented by the following steps, and the open domain takes the ground maintenance system sending data to the ARINC664 network as an example for explanation:

[0055] first step:

[0056] Design an RSA key configuration table of size N for the security gateway, the format of which is shown in Table 1.

[0057] Table 1 RSA key configuration table format

[0058] Serial number Public Key Private Key 1 Public Key 1 Private Key 1 2 Public Key 2 Private Key 2 3 Public Key 3 Private Key 3 …… …… …… N Public Key N Private Key N

[0059] Step 2:

[0060] Before sending data to the onboard system in the aircraft control domain, the ground maintenance system needs to send a communication request message to the security gateway, recorded as Request_Message.

[0061] After receiving the communication request message Request_Message, the security gateway uses a random number algorithm to select a set of public keys and private keys from the RSA key configuration table, recorded as "public key GY" and "private key SY". Then the security gateway replies to the ground maintenance system with a communication response message, recorded as Response_Message, which contains the "public key GY" information.

[0062] Step 3: The ground maintenance system receives the communication response message from the security gateway

[0063] Response_Message, take out the "public key GY" from Response_Message to encrypt the network data to be sent, the steps are as follows:

[0064] Step 31) The ground maintenance system generates a 64-bit "session key K" using a random number algorithm. This session key is used only once and must be deleted after use;

[0065] Step 32) The ground maintenance system groups the network data "plain text M" to be transmitted into 8-byte groups. If the data is less than 8 bytes, it is padded with 0. Figure 4 As shown;

[0066] Step 33) The ground maintenance system combines the "plain text M" and the "session key K" and generates a "CRC32 check code A" (4 bytes) through the CRC32 algorithm, such as Figure 5 As shown;

[0067] Step 34) The ground maintenance system uses the "session key K" to perform DES encryption on each plaintext packet to generate "ciphertext C", such as Figure 6 As shown;

[0068] Step 35) The ground maintenance system uses the "public key GY" to perform RSA encryption on the 64-bit "session key K" of DES to form an encrypted "session key EK", such as Figure 7 As shown;

[0069] Step 36) The ground maintenance system uses the "ciphertext C", "session key EK", and "CRC32 check code A" generated in steps 4, 5, and 3 to generate a network message "C&EK" for transmission. The message format is as follows: Figure 8 As shown;

[0070] Step 37) The ground maintenance system sends the network message "C&EK" to the security gateway.

[0071] In summary, the data encryption process of the ground maintenance system is as follows: Fig. 9 shown.

[0072] Step 4:

[0073] After the security gateway receives the network message "C&EK" sent by the ground maintenance system, it needs to decrypt it first and perform a CRC32 check on the decrypted plaintext data. If the check succeeds, the network data is considered authorized and can be converted to a protocol before being sent to the network switch to enter the aircraft control domain. Otherwise, the network data is considered unauthorized and will be directly discarded. The steps for the security gateway to process the network message "C&EK" are as follows:

[0074] Step 41) The security gateway decomposes the received network message "C&EK" to obtain "ciphertext C", "session key EK", and "CRC32 check code A";

[0075] Step 42) The security gateway uses the "private key SY" to decrypt the "session key EK" to obtain a 64-bit DES "session key K", such as Fig.10 As shown;

[0076] Step 43) The security gateway uses the obtained 64-bit "session key K" to perform DES decryption on the "ciphertext C" to obtain the "plaintext M", such as Fig.11 As shown;

[0077] Step 44) The security gateway combines the "plaintext M" and "session key K" obtained in steps 3 and 2 to perform CRC32 calculation to obtain the "CRC32 check code B", such as Fig.12 As shown;

[0078] Step 45) The security gateway compares "CRC32 check code A" with "CRC32 check code B" to see if they are consistent. If they are inconsistent, the entire network message "C&EK" is discarded;

[0079] Step 46) If the CRC32 check code A is consistent with the CRC32 check code B, the security gateway performs protocol conversion on the "plain text M", packages it into an ARINC664 data frame, and sends it to the network switch.

[0080] To summarize, the decryption flow chart of the security gateway is shown in FIG13 .

[0081] After the security protection mechanism of the present invention is implemented in the gateway, the authorized system (such as Fig.14 The "in-flight entertainment system" and "ground maintenance system" in the "aircraft control domain" can communicate normally with the "aircraft control domain"; while unauthorized systems (such as Fig.14 The hacker in the security gateway cannot send data that can be recognized by the security gateway because he does not understand the security protection mechanism of the security gateway. The security gateway will discard all data sent by the hacker, so that the "security gateway" can effectively block hacker attacks. In addition, the present invention adopts a random number generation method for both the DES session key and the RSA public key / secret key. The key for each communication process is different. Even if the key is leaked, the hacker cannot use the leaked key for data communication. The security gateway will still discard the network data sent by the hacker, so it can effectively block the hacker's attack and ensure the safety of the airborne network, airborne system and aircraft.

[0082] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, and all these changes or substitutions should fall within the protection scope of the claims attached to the present invention.

Claims

1. An airborne network security protection method based on a security gateway, characterized in that The following steps are involved: Step 1: Configure an RSA key configuration table on the security gateway; Step 2: The open domain sends a communication request message to the security gateway. After receiving the communication request message, the security gateway uses a random number algorithm to select a set of public keys and private keys from the RSA key configuration table, recorded as "public key GY" and "private key SY". Then the security gateway replies a communication response message to the open domain, which contains the "public key GY" information. Step 3: After the open domain receives the communication response message from the security gateway, it takes out the "public key GY" to encrypt the network data to be sent. The steps are as follows: Step 31) Generate a 64-bit "session key K" using a random number algorithm; Step 32) The network data to be transmitted is grouped as "plain text M" by 8 bytes, and the ones less than 8 bytes are padded with 0; Step 33) Combine the "plain text M" and the "session key K" and generate a "CRC32 check code A" through the CRC32 algorithm; Step 34) Use the "session key K" to perform DES encryption on each plaintext packet to generate "ciphertext C"; Step 35) Use the "public key GY" to perform RSA encryption on the "session key K" to form the encrypted "session key EK"; Step 36) synthesize the "ciphertext C", "session key EK", and "CRC32 check code A" to generate a network message "C&EK" for transmission; Step 37) The open domain sends the network message "C&EK" to the security gateway; Step 4: After receiving the network message "C&EK" sent by the open domain, the security gateway performs decryption verification. If the verification is successful, the network data is converted to a protocol and then sent to the network switch to enter the aircraft control domain. Otherwise, the network data is considered unauthorized and will be directly discarded. Among them, the security gateway performs the following steps to decrypt and verify the network message "C&EK": Step 41) Decompose the received network message "C&EK" to obtain "ciphertext C", "session key EK", and "CRC32 check code A"; Step 42) Use the "private key SY" to perform RSA decryption on the "session key EK" to obtain the "session key K"; Step 43) Use the "session key K" to perform DES decryption on the "ciphertext C" to obtain the "plaintext M"; Step 44) Combine "plain text M" and "session key K" to perform CRC32 calculation to obtain "CRC32 check code B"; Step 45) Compare "CRC32 check code A" and "CRC32 check code B" to see if they are consistent. If they are inconsistent, discard the entire network message "C&EK"; Step 46) If the CRC32 check code A is consistent with the CRC32 check code B, the security gateway performs protocol conversion on the "plain text M", packages it into an ARINC664 data frame, and sends it to the network switch.

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