Navigation message authentication method and device for navigation satellite PPP-b2b signals

Abstract

The application relates to a navigation message authentication method for navigation satellite PPP-B2b signals, which comprises the following steps: generating a public-private key pair based on an SM2 algorithm, and obtaining a navigation message of a navigation satellite PPP-B2b signal; generating a page digest corresponding to a navigation message page according to an SM3 algorithm; generating a digital signature corresponding to the page digest according to a private key in the public-private key pair; embedding the digital signature in a newly designed message page to generate a new navigation message page; inserting the generated navigation message page into each playing period of the navigation satellite PPP-B2b signal according to a preset rule; uploading the new navigation message page to a navigation satellite; and playing the new navigation message page by the navigation satellite; and verifying whether the new navigation message page is tampered with by using a public key from a public key server. In the technical scheme of the application, the national SM2 asymmetric encryption algorithm and the SM3 hash algorithm are used, so that the security risks and compliance problems possibly existing in the use of foreign encryption algorithms are avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of navigation technology, in particular to a navigation message authentication method and system for navigation satellite PPP-B2b signals, a readable storage medium and a computer device. BACKGROUND

[0002] Since the civil signal system of the global navigation satellite system adopts open design, it makes it easier for fraudsters to counterfeit signals. The main security threat to civil signals at present comes from spoofing attacks. The implementer counterfeits satellite signals that are highly similar to real signals, especially tampers and counterfeits key information in navigation messages, resulting in incorrect positioning results calculated by the receiving device.

[0003] Each GNSS system is actively developing GNSS signal anti-spoofing research. Navigation message authentication technology is favored by various navigation and positioning systems due to its low resource consumption and strong technical compatibility. The Galileo navigation system of the European Union opened the navigation message authentication service OSNMA of the public service signal in 2023. The regional navigation and positioning system QZSS of Japan released the ICD file of QZNMA on the official website in 2024 and opened the signal authentication service.

[0004] As the core carrier of the Beidou-3 system high-precision service, PPP-B2b signals have a wide range of applications and are of great strategic significance. In disaster monitoring, it can capture millimeter-level ground deformation to provide accurate data support for rapid earthquake disaster assessment. In the field of power inspection, satellite-based augmented positioning breaks through the limitations of public networks and significantly improves the efficiency of unmanned aerial vehicle autonomous inspection. In financial transactions, sub-nanosecond timing ensures the accuracy of high-frequency transaction timestamps.

[0005] The existing technology has the following problems: (1) In the signal self-authentication mechanism of QZNMA and OSNMA, the authentication objects are relatively fixed format signals such as LNAV messages and I / NAV messages. However, for signals such as PPP-B2b messages with flexible broadcast modes, existing research still has obvious deficiencies. (2) The cryptographic algorithms used in existing QZNMA and OSNMA authentication schemes are developed by foreign countries, and the Beidou system is a national core military and civilian infrastructure. If it relies on foreign cryptographic algorithms for security authentication, there is a potential risk of security, and it is difficult to meet the security needs of self-controlling. SUMMARY

[0006] The present application aims to at least solve one of the problems in the prior art or related art.

[0007] To this end, the application aims to provide a navigation message authentication method and device for navigation satellite PPP-B2b signals, which can solve the problem of tamper-proofing of Beidou PPP-B2b navigation messages.

[0008] To achieve the above-mentioned purpose, the technical solution of the first aspect of the application provides a navigation message authentication method for navigation satellite PPP-B2b signals, comprising the following steps:

[0009] Step S1, generating a public-private key pair based on the SM2 algorithm, and uploading the public key in the public-private key pair to a public key server for user terminals to obtain;

[0010] Step S2, obtaining the navigation message of the navigation satellite PPP-B2b signal to obtain a navigation message page;

[0011] Step S3, generating a page digest corresponding to the navigation message page according to the SM3 algorithm;

[0012] Step S4, generating a digital signature corresponding to the page digest according to the private key in the public-private key pair;

[0013] Step S5, generating a navigation message new page from the digital signature, and inserting the navigation message new page in each playing period of the navigation satellite PPP-B2b signal according to a preset rule;

[0014] Step S6, uploading the navigation message new page to the navigation satellite, and broadcasting the navigation message new page by the navigation satellite;

[0015] Step S7, after the user terminal receives the navigation message new page from the navigation satellite, verifying the digital signature in the navigation message new page using the public key from the public key server, and determining whether the navigation message is tampered with.

[0016] In the above technical solution, preferably, the digital signature comprises r signature and s signature; the preset rule is the corresponding relationship between the digital signature and the navigation message page in each playing period of the navigation satellite PPP-B2b signal, and specifically comprises:

[0017] The r message is stored in the 5th, 7th, 19th, 31st and 43rd seconds;

[0018] The s message is stored in the 6th, 11th, 23rd, 35th and 47th seconds;

[0019] The complete digital signature composed of the 5th and 6th seconds is used to verify the spliced message composed of page 1, page 2 and page 3 in the current playing period;

[0020] A complete digital signature consisting of the 7th and 11th seconds is used to verify the spliced ​​message formed by splicing the 8th, 9th, and 10th seconds within the current playback cycle;

[0021] A complete digital signature consisting of the 19th and 23rd seconds is used to verify the spliced ​​message formed by splicing the 20th, 21st, and 22nd seconds within the current playback cycle;

[0022] A complete digital signature consisting of the 31st and 35th seconds is used to verify the spliced ​​message formed by splicing the 32nd, 33rd, and 34th seconds within the current playback cycle;

[0023] A complete digital signature consisting of the 43rd and 47th seconds is used to verify the spliced ​​message formed by splicing the 44th, 45th, and 46th seconds within the current playback cycle.

[0024] In the above technical solution, preferably, in step S7, verifying whether the new page of the navigation message has been tampered with using the public key from the public key server specifically includes:

[0025] A verification digest corresponding to the spliced ​​message is generated based on the SM3 algorithm;

[0026] The complete digital signature is verified using the public key from the public key server;

[0027] If the verification is successful, the navigation message is determined to have not been tampered with; if the verification fails, the navigation message is determined to have been tampered with.

[0028] In the above technical solution, preferably, the new navigation message page includes: a 6-bit message type; a 17-bit epoch time; a 4-bit reserved bit; a 2-bit IOD version number; a 2-bit digital signature type; a 256-bit digital signature; a 177-bit reserved bit; and a 22-bit check bit; wherein, when the digital signature type is 00, the message type is an r message; when the digital signature type is 01, the message type is an s message; and the remaining digital signature types are reserved.

[0029] The second aspect of the present invention provides a navigation message authentication system for navigation satellite PPP-B2b signals, comprising:

[0030] The public-private key pair generation module is configured to generate public-private key pairs based on the SM2 algorithm and upload the public key in the public-private key pair to the public key server for user terminals to obtain.

[0031] The navigation message acquisition module is configured to acquire navigation messages from navigation satellite PPP-B2b signals and obtain the navigation message page.

[0032] The page summary module is configured to generate a page summary corresponding to the navigation message page according to the SM3 algorithm;

[0033] The digital signature generation module is configured to generate a digital signature corresponding to the page digest based on the private key in the public-private key pair.

[0034] The new message generation module is configured to generate a new navigation message page from a digital signature and insert the new navigation message page into each playback cycle of the navigation satellite PPP-B2b signal according to a preset rule.

[0035] The new message uploading module is configured to upload the new page of the navigation message to the navigation satellite, and the navigation satellite broadcasts the new page of the navigation message.

[0036] The user terminal is configured to receive a new page of the navigation message from the navigation satellite, and then use the public key from the public key server to verify the digital signature in the new page of the navigation message to determine whether the navigation message has been tampered with.

[0037] In the above technical solution, preferably, the digital signature includes an r-signature and an s-signature; the preset rule is the correspondence between the digital signature and the navigation message page in each playback cycle of the navigation satellite PPP-B2b signal, specifically including:

[0038] The r message is stored at the 5th, 7th, 19th, 31st, and 43rd seconds;

[0039] The s message is stored at the 6th, 11th, 23rd, 35th, and 47th seconds;

[0040] A complete digital signature consisting of the 5th and 6th seconds is used to verify the spliced ​​message composed of pages 1, 2, and 3 within the current playback cycle;

[0041] A complete digital signature consisting of the 7th and 11th seconds is used to verify the spliced ​​message formed by splicing the 8th, 9th, and 10th seconds within the current playback cycle;

[0042] A complete digital signature consisting of the 19th and 23rd seconds is used to verify the spliced ​​message formed by splicing the 20th, 21st, and 22nd seconds within the current playback cycle;

[0043] A complete digital signature consisting of the 31st and 35th seconds is used to verify the spliced ​​message formed by splicing the 32nd, 33rd, and 34th seconds within the current playback cycle;

[0044] A complete digital signature consisting of the 43rd and 47th seconds is used to verify the spliced ​​message formed by splicing the 44th, 45th, and 46th seconds within the current playback cycle.

[0045] In the above technical solution, preferably, the user terminal includes:

[0046] The verification digest generation module is configured to generate a verification digest corresponding to the spliced ​​message based on the SM3 algorithm;

[0047] The signature verification module is configured to verify the complete digital signature based on the public key from the public key server.

[0048] The judgment module is configured to determine that the navigation message has not been tampered with if the signature verification result is successful, and to determine that the navigation message has been tampered with if the signature verification fails.

[0049] In the above technical solution, preferably, the new navigation message page includes: a 6-bit message type; a 17-bit epoch time; a 4-bit reserved bit; a 2-bit IOD version number; a 2-bit digital signature type; a 256-bit digital signature; a 177-bit reserved bit; and a 22-bit check bit; wherein, when the digital signature type is 00, the message type is an r message; when the digital signature type is 01, the message type is an s message; and the remaining digital signature types are reserved.

[0050] The third aspect of the present invention provides a readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the navigation message authentication method for navigation satellite PPP-B2b signals provided in the first aspect of the present invention.

[0051] The fourth aspect of the present invention provides a computer device, including a storage medium and a processor; the storage medium is used to store a computer program; the processor is used to execute the computer program to implement the steps of the navigation message authentication method for navigation satellite PPP-B2b signals provided in the first aspect of the present invention.

[0052] Compared with existing technologies, the advantages of the navigation message authentication method and device for PPP-B2b signals of navigation satellites provided by this invention are as follows:

[0053] 1. Strong security and compliance: It adopts the national cryptographic standard SM2 asymmetric encryption algorithm and SM3 hash algorithm, which comply with national cryptographic standards. While ensuring the security of navigation message authentication, it meets the requirements of relevant domestic laws and regulations and technical specifications, avoiding the security risks and compliance issues that may exist when using foreign encryption algorithms.

[0054] 2. High authentication efficiency: By designing a dedicated 486-bit message type to carry signature information and optimizing the message broadcasting order (based on 10 fixed positions within a 48-second cycle), the signature information and the message to be authenticated are accurately matched, reducing the verification and matching time of the user terminal and improving the overall authentication efficiency.

[0055] 3. Good compatibility: Based on the original framework of PPP-B2b signal, new message types and broadcasting mechanisms are designed without making disruptive modifications to the existing signal system. It can achieve good compatibility with the existing BeiDou navigation system's PPP-B2b signal receiving equipment and system, reducing the cost of technology promotion and application.

[0056] 4. Strong anti-tampering capability: By binding digital signatures with message pages for a specific time period (such as a complete signature consisting of 1 frame of r message and 1 frame of s message corresponding to the verification of a specific spliced ​​message), a targeted authentication link is formed, which can effectively detect whether the message has been tampered with during transmission, ensuring that the navigation message received by the user terminal is authentic and reliable.

[0057] 5. Clear verification logic: The verification process of the user terminal is clearly defined, from public key acquisition, signature concatenation, digest recalculation to signature comparison, forming a complete and easy-to-implement verification closed loop, which is convenient for engineering applications and device integration. Attached Figure Description

[0058] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0059] Figure 1 For the new message page structure;

[0060] Figure 2 The new message page will be displayed in the correct order.

[0061] Figure 3 For the authentication methods of page 3 and page 2;

[0062] Figure 4 This is the digital signature authentication process for PPP-B2b signals. Detailed Implementation

[0063] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0064] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0065] A complete PPP-B2b navigation message authentication system includes authentication information generated by the ground station, authentication information uploaded, authentication information broadcast by the satellite, authentication information received by the user terminal, and authentication information verified by the user.

[0066] like Figures 1 to 4 As shown, a navigation message authentication method for PPP-B2b signals of navigation satellites according to an embodiment of the present invention includes the following steps:

[0067] Step S1: Generate a public-private key pair based on the SM2 algorithm, and upload the public key in the public-private key pair to the public key server for user terminals to obtain;

[0068] In this step, the BeiDou PPP-B2b signal broadcasts the corrections required for precise point positioning, including satellite masks, orbital corrections, inter-symbol offset corrections, and clock bias corrections. These message types each have their corresponding frame formats, i.e., message types. Satellite mask broadcasts the satellites corresponding to the satellite corrections broadcast within the current cycle. Information type 2 corrects the satellite's orbital position. Information type 3 is the inter-symbol offset correction, used to correct the deviation between satellites in different frequency bands and the BeiDou time reference B1I clock. Message type 4, the clock bias correction, corrects the received satellite clock information. This design authenticates pages 1, 2, 3, and 4.

[0069] Table 1 Pages and their validity periods

[0070] Page Message content Validity period 1 Satellite mask -- 2 Satellite orbit correction and user ranging accuracy index 96 3 Code bias correction 86400 4 Satellite clock correction 12 5 User ranging accuracy index 96 6 Clock correction and orbit correction - combination 1 -- 7 Clock correction and orbit correction - combination 1 -- 8-62 Reserved -- 63 Null information --

[0071] This design employs elliptic curve digital signatures to authenticate message pages in PPP-B2b signals. The algorithms used to generate the digital signature include the Chinese national cryptographic algorithms SM2 and SM3.

[0072] SM2 is an asymmetric encryption algorithm. When using SM2 for digital signatures, the message sender holds the private key, and the message receiver holds the public key; the public and private keys are paired. The general process of a digital signature algorithm is as follows: The message sender performs SM3 on message M to generate a 256-bit message digest, then signs the 256-bit message digest with the private key, generating (r, s), where r and s are both 256 bits. The message sender then sends (r, s) along with the message. After receiving message M and the digital signature (r, s), the message receiver first performs SM3 on message M to obtain a 256-bit message digest, then uses the public key and the digest to generate message s', and finally checks whether s = s'.

[0073] SM3 is suitable for digital signatures and verification. It can compute a digest of an input sequence of any length, with the digest being a fixed length of 256 bits.

[0074] Step S2: Obtain the navigation message of the PPP-B2b signal from the navigation satellite and obtain the navigation message page;

[0075] Step S3: Generate a page summary corresponding to the navigation message page according to the SM3 algorithm;

[0076] Step S4: Generate a digital signature corresponding to the page digest based on the private key in the public-private key pair;

[0077] In this step, the digital signature generated by the SM2 algorithm is 512 bits long, divided into two parts: an r-message and an s-message, each 256 bits long. A new page can store either an r-message or an s-message. A 2-bit digital signature type is used to distinguish whether the new type stores an r-message or an s-message. When the 2-bit digital signature type is 00, the message stores the r-message from the digital signature; when it is 01, the message stores the s-message; the rest are reserved.

[0078] Step S5: Generate a new navigation message page from the digital signature, and insert the new navigation message page into each playback cycle of the navigation satellite PPP-B2b signal according to preset rules;

[0079] Step S6: Upload the new navigation message page to the navigation satellite, and have the navigation satellite broadcast the new navigation message page;

[0080] Step S7: After receiving the new navigation message page from the navigation satellite, the user terminal uses the public key from the public key server to verify the digital signature in the new navigation message page to determine whether the navigation message has been tampered with.

[0081] In the above embodiments, preferably, Figure 2This is a new message page broadcasting system. If page 1 is taken as the first second, the position of the new page (blue) within a cycle has been marked. The digital signature includes an r-signature and an s-signature; the preset rule is that within each playback cycle of the navigation satellite PPP-B2b signal, each playback cycle is 48 seconds. The first second of each playback cycle plays message type 1, i.e., page 1; the second second plays message type 2, i.e., page 2; and so on for page 3. The correspondence between the digital signature and the navigation message page specifically includes:

[0082] The r message is stored at the 5th, 7th, 19th, 31st, and 43rd seconds;

[0083] The s message is stored at the 6th, 11th, 23rd, 35th, and 47th seconds;

[0084] A complete digital signature consisting of the 5th and 6th seconds is used to verify the spliced ​​message composed of pages 1, 2, and 3 within the current playback cycle;

[0085] A complete digital signature consisting of the 7th and 11th seconds is used to verify the spliced ​​message formed by splicing the 8th, 9th, and 10th seconds within the current playback cycle;

[0086] A complete digital signature consisting of the 19th and 23rd seconds is used to verify the spliced ​​message formed by splicing the 20th, 21st, and 22nd seconds within the current playback cycle;

[0087] A complete digital signature consisting of the 31st and 35th seconds is used to verify the spliced ​​message formed by splicing the 32nd, 33rd, and 34th seconds within the current playback cycle;

[0088] A complete digital signature consisting of the 43rd and 47th seconds is used to verify the spliced ​​message formed by splicing the 44th, 45th, and 46th seconds within the current playback cycle.

[0089] In this embodiment, Figure 3 This demonstrates the authentication relationship between messages such as page 3 and page 2: within a cycle, pages 3 and 2 are concatenated end-to-end to form a new message. Then, an SM3 hash is performed on the message to obtain a digest. An SM2 digital signature is then applied to the digest, resulting in (r, s). Two new message pages are generated using the digital signature, and these two message pages are then placed at the 5th and 6th seconds of a cycle.

[0090] like Figure 2As shown, the PPP-B2b signal broadcast cycle is 48 seconds. Satellite mask information is broadcast in the first second. The position of page 4 (at the 4th second) is fixed within the 48-second cycle, while the positions of the other pages are variable. As shown in the figure, this invention inserts page 8 (at the 8th second) into the 48-second cycle, and the position of page 8 is also fixed. There are two types of digital signature messages. The orange pair of (r, s) digital signature messages verifies pages 1, 2, and 3, authenticating pages 1, 2, and 3 within the current playback cycle. The other pair of green digital signatures is used to verify page 4 (at the 4th second), which precedes these two messages. The verification correspondence is shown in the table below.

[0091] Table 2 Digital Signatures and Corresponding Verification Page Timing

[0092]

[0093] In the above embodiments, preferably, in step S7, verifying whether the new page of the navigation message has been tampered with using the public key from the public key server specifically includes:

[0094] A verification digest corresponding to the spliced ​​message is generated based on the SM3 algorithm;

[0095] The complete digital signature is verified using the public key from the public key server;

[0096] If the verification is successful, the navigation message is determined to have not been tampered with; if the verification fails, the navigation message is determined to have been tampered with.

[0097] In the above embodiments, preferably, Figure 1 This is a detailed structural diagram of the new navigation page. The new page consists of 486 bits. The navigation message on the new page, from MSB to LSB, includes: 6 bits for the message type (MesType ID); 17 bits for the epoch time; 4 bits for the reserved bits (Rev); 2 bits for the IOD version number (IOD SSR); 2 bits for the digital signature type (SignType); 256 bits for the digital signature (Digital Signature); 177 bits for the reserved bits (Rev); and 22 bits for the check bit (CRC). When the digital signature type is 00, the message type is an r message; when the digital signature type is 01, the message type is an s message; the remaining digital signature types are reserved.

[0098] like Figures 1 to 4 As shown, a navigation message authentication system for navigation satellite PPP-B2b signals according to another embodiment of the present invention includes:

[0099] The public-private key pair generation module is configured to generate public-private key pairs based on the SM2 algorithm and upload the public key in the public-private key pair to the public key server for user terminals to obtain.

[0100] The navigation message acquisition module is configured to acquire navigation messages from navigation satellite PPP-B2b signals and obtain the navigation message page.

[0101] The page summary module is configured to generate a page summary corresponding to the navigation message page according to the SM3 algorithm;

[0102] The digital signature generation module is configured to generate a digital signature corresponding to the page digest based on the private key in the public-private key pair.

[0103] The new message generation module is configured to generate a new navigation message page from a digital signature and insert the new navigation message page into each playback cycle of the navigation satellite PPP-B2b signal according to a preset rule.

[0104] The new message uploading module is configured to upload the new page of the navigation message to the navigation satellite, and the navigation satellite broadcasts the new page of the navigation message.

[0105] The user terminal is configured to receive a new page of the navigation message from the navigation satellite, and then use the public key from the public key server to verify the digital signature in the new page of the navigation message to determine whether the navigation message has been tampered with.

[0106] In the above embodiments, preferably, the digital signature includes an r-signature and an s-signature; the preset rule is the correspondence between the digital signature and the navigation message page in each playback cycle of the navigation satellite PPP-B2b signal, specifically including:

[0107] The r message is stored at the 5th, 7th, 19th, 31st, and 43rd seconds;

[0108] The s message is stored at the 6th, 11th, 23rd, 35th, and 47th seconds;

[0109] A complete digital signature consisting of the 5th and 6th seconds is used to verify the spliced ​​message composed of pages 1, 2, and 3 within the current playback cycle;

[0110] A complete digital signature consisting of the 7th and 11th seconds is used to verify the spliced ​​message formed by splicing the 8th, 9th, and 10th seconds within the current playback cycle;

[0111] A complete digital signature consisting of the 19th and 23rd seconds is used to verify the spliced ​​message formed by splicing the 20th, 21st, and 22nd seconds within the current playback cycle;

[0112] A complete digital signature consisting of the 31st and 35th seconds is used to verify the spliced ​​message formed by splicing the 32nd, 33rd, and 34th seconds within the current playback cycle;

[0113] A complete digital signature consisting of the 43rd and 47th seconds is used to verify the spliced ​​message formed by splicing the 44th, 45th, and 46th seconds within the current playback cycle.

[0114] In the above embodiments, preferably, the user terminal includes:

[0115] The verification digest generation module is configured to generate a verification digest corresponding to the spliced ​​message based on the SM3 algorithm;

[0116] The signature verification module is configured to verify the complete digital signature based on the public key from the public key server.

[0117] The judgment module is configured to determine that the navigation message has not been tampered with if the signature verification result is successful, and to determine that the navigation message has been tampered with if the signature verification fails.

[0118] In the above embodiments, preferably, the new navigation message page includes: a 6-bit message type; a 17-bit epoch time; a 4-bit reserved bit; a 2-bit IOD version number; a 2-bit digital signature type; a 256-bit digital signature; a 177-bit reserved bit; and a 22-bit check bit; wherein, when the digital signature type is 00, the message type is an r message; when the digital signature type is 01, the message type is an s message; and the remaining digital signature types are reserved.

[0119] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the navigation message authentication method for navigation satellite PPP-B2b signals of any of the above embodiments.

[0120] Based on this understanding, the technical solution of this application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as CD-ROM, USB flash drive, mobile hard drive, etc.) and includes several instructions to cause a computer device (such as personal computer, server, or network device, etc.) to execute the methods of various implementation scenarios of this application.

[0121] This application also provides a computer device, including a storage medium and a processor; the storage medium is used to store a computer program; the processor is used to execute the computer program to implement the steps of the navigation message authentication method for navigation satellite PPP-B2b signals of any of the above embodiments.

[0122] Optionally, the computer device may also include a user interface, a network interface, a camera, radio frequency (RF) circuitry, sensors, audio circuitry, a Wi-Fi module, etc. The user interface may include a display screen, input units such as a keyboard, etc., and optional user interfaces may also include USB interfaces, card reader interfaces, etc. The network interface may optionally include standard wired interfaces, wireless interfaces (such as Bluetooth interfaces, Wi-Fi interfaces), etc.

[0123] Those skilled in the art will understand that the computer device structure provided in this embodiment does not constitute a limitation on the computer device, and may include more or fewer components, or combine certain components, or have different component arrangements.

[0124] The storage medium may also include an operating system and a network communication module. The operating system is a program that manages and stores the hardware and software resources of a computer device, supporting the operation of information processing programs and other software and / or programs. The network communication module is used to enable communication between the various components within the storage medium, as well as communication with other hardware and software within the physical device.

[0125] In this invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0126] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0127] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0128] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A navigation message authentication method for navigation satellite PPP-B2b signals, characterized in that, Includes the following steps: Step S1: Generate a public-private key pair based on the SM2 algorithm, and upload the public key in the public-private key pair to the public key server for user terminals to obtain; Step S2: Obtain the navigation message of the PPP-B2b signal from the navigation satellite and obtain the navigation message page; Step S3: Generate a page summary corresponding to the navigation message page according to the SM3 algorithm; Step S4: Generate a digital signature corresponding to the page digest based on the private key in the public-private key pair; Step S5: Generate a new navigation message page from the digital signature, and insert the new navigation message page into each playback cycle of the navigation satellite PPP-B2b signal according to preset rules; The new navigation message page includes: a 6-bit message type; a 17-bit epoch time; a 4-bit reserved bit; a 2-bit IOD version number; a 2-bit digital signature type; a 256-bit digital signature; a 177-bit reserved bit; and a 22-bit check bit. Wherein, when the digital signature type is 00, the message type is an r-message; when the digital signature type is 01, the message type is an s-message; the remaining digital signature types are reserved. The digital signature includes an r-signature and an s-signature; the preset rule is the correspondence between the digital signature and the navigation message page in each playback cycle of the navigation satellite PPP-B2b signal, specifically including: The r message is stored at the 5th, 7th, 19th, 31st, and 43rd seconds; The s message is stored at the 6th, 11th, 23rd, 35th, and 47th seconds; A complete digital signature consisting of the 5th and 6th seconds is used to verify the concatenated message composed of pages 1, 2, and 3 within the current cycle; A complete digital signature consisting of the 7th and 11th seconds is used to verify the spliced ​​message formed by splicing the 8th, 9th, and 10th seconds within the current playback cycle; A complete digital signature consisting of the 19th and 23rd seconds is used to verify the spliced ​​message formed by splicing the 20th, 21st, and 22nd seconds within the current playback cycle; A complete digital signature consisting of the 31st and 35th seconds is used to verify the spliced ​​message formed by splicing the 32nd, 33rd, and 34th seconds within the current playback cycle; A complete digital signature consisting of the 43rd and 47th seconds is used to verify the spliced ​​message formed by splicing the 44th, 45th, and 46th seconds within the current playback cycle; Step S6: Upload the new navigation message page to the navigation satellite, and have the navigation satellite broadcast the new navigation message page; Step S7: After receiving the new navigation message page from the navigation satellite, the user terminal uses the public key from the public key server to verify the digital signature in the new navigation message page to determine whether the navigation message has been tampered with.

2. The navigation message authentication method for navigation satellite PPP-B2b signals according to claim 1, characterized in that, In step S7, the public key from the public key server is used to verify whether the new page of the navigation message has been tampered with, specifically including: A verification digest corresponding to the spliced ​​message is generated based on the SM3 algorithm; The complete digital signature is verified using the public key from the public key server; If the verification is successful, the navigation message is determined to have not been tampered with; if the verification fails, the navigation message is determined to have been tampered with.

3. A navigation message authentication system for PPP-B2b signals from navigation satellites, characterized in that, include: The public-private key pair generation module is configured to generate public-private key pairs based on the SM2 algorithm and upload the public key in the public-private key pair to the public key server for user terminals to obtain. The navigation message acquisition module is configured to acquire navigation messages from navigation satellite PPP-B2b signals and obtain the navigation message page. The page summary module is configured to generate a page summary corresponding to the navigation message page according to the SM3 algorithm; The digital signature generation module is configured to generate a digital signature corresponding to the page digest based on the private key in the public-private key pair. The new message generation module is configured to generate a new navigation message page from a digital signature and insert the new navigation message page into each playback cycle of the navigation satellite PPP-B2b signal according to a preset rule. The new navigation message page includes: a 6-bit message type; a 17-bit epoch time; a 4-bit reserved bit; a 2-bit IOD version number; a 2-bit digital signature type; a 256-bit digital signature; a 177-bit reserved bit; and a 22-bit check bit. Wherein, when the digital signature type is 00, the message type is an r-message; when the digital signature type is 01, the message type is an s-message; the remaining digital signature types are reserved. The digital signature includes an r-signature and an s-signature; the preset rule is the correspondence between the digital signature and the navigation message page in each playback cycle of the navigation satellite PPP-B2b signal, specifically including: The r message is stored at the 5th, 7th, 19th, 31st, and 43rd seconds; The s message is stored at the 6th, 11th, 23rd, 35th, and 47th seconds; A complete digital signature consisting of the 5th and 6th seconds is used to verify the concatenated message composed of pages 1, 2, and 3 within the current cycle; A complete digital signature consisting of the 7th and 11th seconds is used to verify the spliced ​​message formed by splicing the 8th, 9th, and 10th seconds within the current playback cycle; A complete digital signature consisting of the 19th and 23rd seconds is used to verify the spliced ​​message formed by splicing the 20th, 21st, and 22nd seconds within the current playback cycle; A complete digital signature consisting of the 31st and 35th seconds is used to verify the spliced ​​message formed by splicing the 32nd, 33rd, and 34th seconds within the current playback cycle; A complete digital signature consisting of the 43rd and 47th seconds is used to verify the spliced ​​message formed by splicing the 44th, 45th, and 46th seconds within the current playback cycle; The new message uploading module is configured to upload the new page of the navigation message to the navigation satellite, and the navigation satellite broadcasts the new page of the navigation message. The user terminal is configured to receive a new page of the navigation message from the navigation satellite, and then use the public key from the public key server to verify the digital signature in the new page of the navigation message to determine whether the navigation message has been tampered with.

4. The navigation message authentication system for PPP-B2b signals of navigation satellites according to claim 3, characterized in that, User terminals include: The verification digest generation module is configured to generate a verification digest corresponding to the spliced ​​message based on the SM3 algorithm; The signature verification module is configured to verify the complete digital signature based on the public key from the public key server. The judgment module is configured to determine that the navigation message has not been tampered with if the signature verification result is successful, and to determine that the navigation message has been tampered with if the signature verification fails.

5. A readable storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the steps of the navigation message authentication method for navigation satellite PPP-B2b signals as described in claim 1 or 2.

6. A computer device, characterized in that, It includes a storage medium and a processor; the storage medium is used to store a computer program; the processor is used to execute the computer program to implement the steps of the navigation message authentication method for navigation satellite PPP-B2b signals as described in claim 1 or 2.

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