A method for securing multicast communications

Abstract

The application discloses a multicast communication security guarantee method, comprising the following steps: a multicast sender periodically sends multicast messages; after a receiver receives the multicast messages, if there is no security check requirement for the received information, the receiver directly uses a security code to check the message integrity, directly uses the message after checking the message disorder, deletion and repetition according to a time stamp and a serial number; and if there is a security check requirement for the received information, the receiver performs security check, including verifying a security signature by using a pre-configured encryption algorithm and key, checking the message integrity, disorder, deletion and repetition, and performing delay check. The application can save communication bandwidth, reduce the number of links and simplify link management based on multicast mechanism transmission of security information.

Description

Technical Field

[0001] This invention belongs to the field of communication technology, specifically relating to multicast communication security technology. Background Technology

[0002] Currently, the rail transit sector widely uses secure communication protocols such as RSSP-I and RSSP-II, both of which are point-to-point secure communication protocols. However, with the increase in application scenarios with multicast characteristics, such as vehicle-to-vehicle communication and online coupling and decoupling, the use of existing point-to-point secure communication protocols has the disadvantages of having many communication objects to manage, repeated data transmissions, and large bandwidth consumption. Summary of the Invention

[0003] For multicast application scenarios, the technical problem to be solved by this invention is to provide a security method suitable for multicast application scenarios, which saves communication bandwidth and ensures the security of multicast communication.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] A method for ensuring multicast communication security includes the following steps:

[0006] The multicast sender periodically sends multicast messages, which contain the following information:

[0007] a) Multicast sender ID, used to identify multicast devices;

[0008] b) Multicast message identification ID, used to identify the multicast message type;

[0009] c) Multicast message timestamp and sequence number;

[0010] d) Broadcast text styles;

[0011] e) Multicast message security code;

[0012] f) Secure signature for multicast messages;

[0013] After receiving a multicast message, if the receiver has no security requirements for the received information, it can directly use the security code to check the integrity of the message. After checking for message reordering, deletion, and duplication based on the timestamp and sequence number, the message can be used directly.

[0014] After receiving a multicast message, if the receiver has security check requirements for the received information, it shall perform the following operations: a) The communicating parties pre-configure encryption algorithms and keys, use the pre-configured encryption algorithms and keys to verify the security signature, and after the verification is successful, accept the message and check the message integrity, out-of-order, deletion and duplication. After the check is successful, a delay check shall be performed.

[0015] b) Upon receiving the message for the first time, the receiver immediately sends a time check message to the multicast sender:

[0016] c) When the multicast sender receives the time check message, it checks the message signature, security code, and sending timestamp. If the check passes, it calculates the message's security delay by subtracting the timestamp of the multicast sender that last received the message from the local timestamp plus the duration the receiver has stored the message. If the security delay is within the specified time range, the time check message is valid, and a time check response message is sent to the receiver.

[0017] d) When the receiver receives the time check response message, it checks the message signature, security code, and sending timestamp. After the check passes, it calculates the security delay of the message by subtracting the "latest receiving timestamp of the receiver + duration for which the multicast sender keeps the message" from the local timestamp. If the security delay is within the specified time range, the time check response message is valid.

[0018] After the receiver checks the validity of the acknowledgment message at the confirmation time, it checks the security delay of the latest received message based on the timestamp of the message. If the security delay passes, the message is used.

[0019] Preferably, the time check message includes:

[0020] i. The recipient's ID;

[0021] i. The recipient's sending timestamp;

[0022] ii. Received the multicast sender ID;

[0023] i v. The timestamp of the multicast sender that received the latest message + the duration for which the receiver retains the message;

[0024] v. Time-check message security code;

[0025] vi. Time-check message signature.

[0026] Preferably, the time check response message includes:

[0027] i. The ID of the multicast sender;

[0028] i. The timestamp of the multicast sender;

[0029] ii. Receive recipient ID;

[0030] i v. The latest timestamp of the message sent by the recipient + the duration for which the multicast sender retains the message;

[0031] v. Time-check message security code;

[0032] vi. Time-check message signature.

[0033] Preferably, the method for calculating the security delay is: the sending timestamp of the latest received message packet - (the timestamp of the last received time check response packet + the duration for which the receiver has stored the information).

[0034] Preferably, the duration for which the receiver has stored the information takes into account the clock discrepancies between the two parties, and when the discrepancy exceeds a set threshold over time, the time check process needs to be re-initiated.

[0035] This invention transmits security information based on a multicast mechanism, which can save communication bandwidth, reduce the number of links, and simplify link management.

[0036] The specific technical solutions adopted in this invention and their beneficial effects will be disclosed in detail in the following specific embodiments in conjunction with the accompanying drawings. Attached Figure Description

[0037] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0038] Figure 1 This is a schematic diagram of the multicast communication process of the present invention. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be explained and described below with reference to the accompanying drawings. However, the following embodiments are only preferred embodiments of the present invention and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments in the implementation methods without creative effort are all within the protection scope of the present invention.

[0040] To address the shortcomings of existing point-to-point secure communication, this invention proposes a secure communication assurance method applicable to multicast application scenarios, including vehicle-to-vehicle communication, online connection and disconnection, and other multicast-featured application scenarios.

[0041] Secure communication protocols need to address seven major threats: corruption, spoofing, insertion, delay, out-of-order delivery, deletion (loss), and duplication. The basic principles are as follows:

[0042] 1. Protection against damage to communication data is achieved by adding a security code. Since the security code can be verified based on a single message, the security code method used in point-to-point communication can be directly applied to multicast scenarios.

[0043] 2. Protection against the dangers of communication data spoofing and insertion can be achieved through methods such as secure encryption of the communication channel and pre-agreed, non-public keys and key algorithms. The first method is guaranteed by the underlying communication platform, while the second method does not involve key negotiation between multiple machines, so there are no special design requirements in multicast scenarios.

[0044] 3. Insertion, delay, out-of-order delivery, deletion (loss), and duplication are generally detected by adding timestamps and sequence numbers to the communication data. For messages sent at equal intervals, the sequence number can replace the timestamp. By checking the order and repetition of timestamps and sequence numbers in consecutive messages, out-of-order delivery and duplication can be detected. Insertion can be considered a special case of out-of-order delivery and duplication; a delayed sequence number indicates a duplicate message, while an excessively advanced sequence number indicates out-of-order delivery. Checking the continuity of sequence numbers can detect deletion (loss). In periodic communication, a certain degree of tolerance for loss is generally acceptable. For these issues, except for the initial timestamp and sequence number, the relationship between consecutive messages can be checked. The same checking method is used for unicast and multicast scenarios.

[0045] 4. Delay checking involves calculating the difference between the timestamps of the communicating parties by exchanging timestamp information. Based on the sending timestamp of the communication message, the message transmission delay can be estimated.

[0046] Based on the principles of the aforementioned secure communication protocol, refer to Figure 1 The security measures for multicast communication are as follows:

[0047] The multicast sender periodically sends multicast messages containing the following information:

[0048] a) Multicast sender ID, used to identify multicast devices;

[0049] b) Multicast message identification ID, used to mark the multicast message type and reflect the message format;

[0050] c) Multicast message timestamp and sequence number;

[0051] d) Multicast message type, multicast business message content;

[0052] e) Multicast message security code;

[0053] f) Secure signature for multicast messages. This is required in open communication environments where the channel does not support anti-spoofing or anti-insertion measures.

[0054] After receiving a multicast message, if the receiver has no security requirements for the received information, it can directly use the security code to check the integrity of the message. After checking for message reordering, deletion, and duplication based on the timestamp and sequence number, the message can be used directly.

[0055] After receiving a multicast message, if the receiver needs to perform a security check on the received information before using it, it should perform the following operations:

[0056] a) All communicating parties pre-configure encryption algorithms and keys, and use these pre-configured algorithms and keys to verify the secure signature. Upon successful verification, the message is accepted. The message is then checked for integrity, out-of-order delivery, deletion, and duplication. After these checks pass, a delay check is performed.

[0057] b) Upon receiving the message for the first time, the received timestamp cannot be checked because the timestamp difference between the communicating parties has not been verified. Therefore, the receiver needs to immediately send a time check message. This time check message contains:

[0058] i. The recipient's ID;

[0059] i. The recipient's sending timestamp;

[0060] ii. Received the multicast sender ID;

[0061] i v. The timestamp of the multicast sender that received the latest message + the duration for which the receiver retains the message;

[0062] v. Time-check message security code;

[0063] vi. Time-check message signature.

[0064] c) When the multicast sender receives the time check message, after verifying the message signature, security code, and sending timestamp, it subtracts the "timestamp of the most recently received multicast sender + the duration for which the receiver retains the message" from the local timestamp.

[0065] Calculate the security delay of the message. If the security delay is within the specified time range, the time check message is valid. Send a time check response message to the receiver. This response message includes:

[0066] i. The ID of the multicast sender;

[0067] i. The timestamp of the multicast sender;

[0068] ii. Receive recipient ID;

[0069] i v. The latest timestamp of the message sent by the recipient + the duration for which the multicast sender retains the message;

[0070] v. Time-check message security code;

[0071] vi. Time-check message signature.

[0072] d) When the receiver receives the time check response message, after the message signature, security code and sending timestamp are checked and passed, the security delay of the message is calculated by subtracting the "latest sending timestamp of the receiver + the duration for which the multicast sender keeps the message" from the local timestamp. If the security delay is within the specified time range, the time check response message is valid.

[0073] Once the receiver confirms the validity of the time check response message, it can check the security delay of the latest received message based on the message's timestamp. The calculation method is: the sending timestamp of the latest received message message - (the timestamp of the last received time check response message + the duration the receiver has stored this information). Furthermore, the "duration the receiver has stored this information" needs to account for the discrepancy between the security clocks of both parties. If this discrepancy accumulates over time and exceeds a set threshold, the time check process needs to be re-initiated to ensure the availability of secure communication.

[0074] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes, but is not limited to, the contents described in the accompanying drawings and the specific embodiments above. Any modifications that do not depart from the functional and structural principles of the present invention will be included within the scope of the claims.

Claims

1. A method for ensuring multicast communication security, characterized in that, Includes the following steps: The multicast sender periodically sends multicast messages, which contain the following information: a) Multicast sender ID, used to identify multicast devices; b) Multicast message identification ID, used to identify the multicast message type; c) Multicast message timestamp and sequence number; d) Broadcast text styles; e) Multicast message security code; f) Secure signature for multicast messages; After receiving a multicast message, if the receiver has no security requirements for the received information, it can directly use the security code to check the integrity of the message. After checking for message reordering, deletion, and duplication based on the timestamp and sequence number, the message can be used directly. After receiving a multicast message, if the receiver requires security checks on the received information, it shall perform the following operations: a) All parties to the communication pre-configure encryption algorithms and keys, use the pre-configured encryption algorithms and keys to verify the secure signature, and after the verification is successful, accept the message and check the message integrity, out-of-order, deletion and duplication. After the check is successful, a delay check is performed. b) Upon receiving the message for the first time, the receiver immediately sends a time check message to the multicast sender: c) When the multicast sender receives the time check message, it checks the message signature, security code, and sending timestamp. If the check passes, it calculates the message's security delay by subtracting the timestamp of the most recently received multicast sender from the local timestamp plus the duration the receiver has stored the message. If the security delay is within the specified time range, the time check message is valid, and a time check response message is sent to the receiver. d) When the receiver receives the time check response message, it checks the message signature, security code, and sending timestamp. After the check passes, it calculates the security delay of the message by subtracting the "latest receiving timestamp of the receiver + duration for which the multicast sender keeps the message" from the local timestamp. If the security delay is within the specified time range, the time check response message is valid. After the receiver checks the validity of the acknowledgment message at the confirmation time, it checks the security delay of the latest received message based on the timestamp of the message. If the security delay passes, the message is used.

2. The multicast communication security assurance method according to claim 1, characterized in that, The time check message contains: i. The recipient's ID; ii. The recipient's sending timestamp; iii. Receive the multicast sender ID; iv. The timestamp of the multicast sender that received the latest message + the duration for which the receiver retains the message; v. Time-check message security code; vi. Time-check message signature.

3. The multicast communication security assurance method according to claim 2, characterized in that, The time check response message includes: i. The ID of the multicast sender; ii. The sending timestamp of the multicast sender; iii. Receive the recipient ID; iv. The latest timestamp of the message sent by the recipient + the duration for which the multicast sender retains the message; v. Time-check message security code; vi. Time-check message signature.

4. The multicast communication security assurance method according to claim 1, characterized in that, The method for calculating the security delay is: the sending timestamp of the latest received message - (the timestamp of the last received time check response message + the duration for which the receiver has stored the information).

5. A multicast communication security assurance method according to claim 4, characterized in that, The duration for which the receiver has stored this information takes into account the safety clock deviation between the two parties. When the deviation value exceeds a set threshold over time, the time check process needs to be re-initiated.

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