Intelligent alarm information management terminal and alarm host data interaction method and system

Abstract

The application relates to an intelligent alarm information management terminal and alarm host data interaction method and system, and relates to the field of data management. A string in alarm information is matched with a hierarchical reference dictionary and an extended dictionary to obtain corresponding dictionary indexes. Numerical value identifiers in the alarm information are output, and binary data converted according to a preset point quantization rule is attached to form compressed data flow. A shift amount is derived by using a transformation key, and a cyclic bit shift operation is performed on the dictionary indexes in the compressed data flow to obtain encrypted compressed data flow. The numerical value identifiers and the binary data do not participate in the shift operation. Independent round trip time (RTT) and retransmission timeout (RTO) are maintained for different service priority levels. If an acknowledgement (ACK) message from the alarm host is not received within the RTO corresponding to the current service priority level, retransmission is performed. When the ACK message returned by the alarm host is received, the RTT and the RTO of the corresponding service priority level are updated.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of communication security, and particularly relates to an intelligent alarm information management terminal and alarm host data interaction method and system. BACKGROUND

[0002] An intelligent alarm system plays a great role in ensuring the safety of families, communities, factories and financial institutions, etc. Generally speaking, such a system is usually composed of a large number of front-end devices such as smoke detectors, infrared sensors, door magnets, etc. and an alarm host, a background server. The front-end device is responsible for real-time monitoring of the environmental state, and when an abnormal event such as a fire or illegal intrusion is detected, it sends a signal to the alarm host through a signal transmission method. The alarm host generates an alarm information and reports it to the intelligent alarm information management terminal and the server through wired and wireless networks such as NB-IoT, LoRaWAN or Wi-Fi for recording. The efficiency, security and reliability of data interaction are the key to determine the performance of the entire system. The alarm host is often a resource-limited device, and the wireless communication channel bandwidth is also limited. In addition, in some key places such as banks, alarm information involves user safety and privacy, and transmission in an open wireless network faces security threats such as eavesdropping, tampering and replay attacks. The Constrained Application Protocol (CoAP) based on UDP provides a lightweight acknowledgement and retransmission mechanism to cope with network packet loss. However, it does not distinguish the priority of the business, and all messages use a unified retransmission strategy, which is unreasonable in the intelligent alarm scenario. For example, the urgency of fire alarm is much higher than that of device low power prompt, and if both of them have the same transmission delay due to network congestion, it may cause serious consequences. The CoAP retransmission timeout (RTO) calculation mainly depends on the network round trip time (RTT) and fails to effectively combine the real-time processing state of the alarm host. When the alarm host causes queue backlog and response delay due to processing a large number of concurrent requests, the terminal may prematurely retransmit due to the inability to perceive the load of the alarm host, which will further aggravate the burden of the alarm host and network congestion, forming a vicious cycle and reducing the stability and response timeliness of the entire system. SUMMARY

[0003] In view of the problems of large data volume and insecurity in the interaction between the current alarm host and the intelligent alarm information management terminal, the application provides an intelligent alarm information management terminal and alarm host data interaction method and system. The method comprises the following steps:

[0004] The intelligent alarm information management terminal and an alarm host are preset with a hierarchical reference dictionary, and an extended dictionary is synchronously maintained according to historical interaction data; a string in alarm information is matched with the hierarchical reference dictionary and the extended dictionary, and a corresponding dictionary index is output if the matching is successful; for numerical data in the alarm information, a numerical identifier and binary data converted according to a preset point quantization rule are output; and the compressed data stream is formed together;

[0005] A transformation key is generated based on a message sequence number and a timestamp bound to a pre-shared key and an alarm information service priority level, a shift amount is derived using the transformation key, a cyclic bit shift operation is performed on the dictionary index in the compressed data stream, and an encrypted compressed data stream is obtained, wherein the numerical identifier and the binary data do not participate in the shift operation;

[0006] The terminal places the encrypted compressed data stream in the payload part of a CoAP message, and sets a custom Option containing the service priority level and the message sequence number in the Option field of the CoAP message.

[0007] The terminal maintains independent round-trip time (RTT) and retransmission timeout (RTO) for different service priority levels; after sending the CoAP message, if an acknowledgement (ACK) from the alarm host is not received within the RTO corresponding to the current service priority level, retransmission is performed; when an ACK message returned by the alarm host is received, the RTT and the RTO of the corresponding service priority level are updated according to the reception time of the ACK and the queue load factor carried in the ACK.

[0008] Optionally, the hierarchical reference dictionary includes a static core dictionary layer and a semi-static application dictionary layer; the static core dictionary layer contains general vocabulary that is fixed and unchanged in alarm services; and the semi-static application dictionary layer contains exclusive vocabulary that remains unchanged in a specific application scenario within a period of time.

[0009] Optionally, the preset point quantization rule is that the numerical data is multiplied by a preset quantization factor, and then the obtained integer is converted into a 16-bit length binary complement form.

[0010] Optionally, the transformation key is generated based on a message sequence number and a timestamp bound to a pre-shared key and an alarm information service priority level, and specifically:

[0011] The pre-shared key is used as the master key of an HMAC-SHA256 hash function, a message formed by concatenating the message sequence number and the timestamp is used as input, and a 256-bit hash value obtained by calculation is the transformation key.

[0012] Optionally, the dictionary index in the compressed data stream is subjected to a cyclic bit shift operation to obtain an encrypted compressed data stream, specifically:

[0013] The value of the lowest 4 bits of the transformation key is taken as the shift amount;

[0014] And for each 12-bit length dictionary index in the compressed data stream, a left cyclic bit shift operation specified by the shift amount is performed.

[0015] Optionally, a custom Option set in the Option field of the CoAP message uses a reserved Option number 2048; the value of the custom Option is a 2-byte field, wherein the high 2 bits are used to represent the service priority level, and the low 14 bits are used to represent the message sequence number.

[0016] Optionally, the RTT and RTO of the corresponding service priority level are updated according to the receiving time of the ACK and the alarm host queue load factor carried therein, specifically:

[0017] After receiving the alarm host confirmation ACK message, the sample round trip time SampleRTT of the current message is calculated;

[0018] According to the formula The round trip time deviation RTTVAR is updated, is a weight coefficient;

[0019] According to the formula The weighted average round trip time SRTT is updated;

[0020] According to the formula The retransmission timeout RTO is updated, wherein is equal to the alarm host queue load factor multiplied by a preset time coefficient, 、 is a weight coefficient; SRTT is the average round trip time, is the SRTT value before updating, is the updated SRTT value, RTTVAR is the round trip time deviation, is the RTTVAR value before updating, is the newly calculated RTTVAR value, RTO new is the updated retransmission timeout RTO value.

[0021] The present application also provides an intelligent alarm information management terminal and alarm host data interaction system, comprising:

[0022] The compression unit, the intelligent alarm information management terminal and the alarm host are preset with a hierarchical reference dictionary, and an extended dictionary is synchronously maintained according to historical interaction data; a string in the alarm information is matched with the hierarchical reference dictionary and the extended dictionary, and if the matching is successful, the corresponding dictionary index is output; for the numerical value type data in the alarm information, the numerical value identifier and the binary data converted according to the preset point quantization rule are output; and the compression data stream is formed together;

[0023] The encryption unit generates a transformation key based on the message sequence number and the timestamp bound with the alarm information service priority level, and derives a shift amount by using the transformation key, so that a cyclic bit shift operation is performed on the dictionary index in the compressed data stream, and the encrypted compressed data stream is obtained, wherein the numerical value identifier and the binary data do not participate in the shift operation.

[0024] The data packet generation unit places the encrypted compressed data stream in the payload part of the CoAP message, and sets a custom Option containing the service priority level and the message sequence number in the Option field of the CoAP message.

[0025] The transmission unit maintains independent round trip time (RTT) and retransmission timeout (RTO) for different service priority levels; after the CoAP message is sent, if an acknowledgement (ACK) from the alarm host is not received within the RTO corresponding to the current service priority level, retransmission is performed; when the ACK message returned by the alarm host is received, the RTT and the RTO of the corresponding service priority level are updated according to the reception time of the ACK and the queue load factor carried in the ACK.

[0026] The present application indexes the string by adopting the hierarchical reference dictionary and the extended dictionary in combination, and performs fixed-point quantization on the numerical value type data, so that the compression of the alarm information is realized, and the transmission data amount is significantly reduced. Meanwhile, the key generated based on the pre-shared key, the message sequence number and the timestamp is used to perform the cyclic bit shift on the dictionary index, a lightweight encryption method is constructed, the confidentiality of the alarm information is ensured on the premise that the calculation burden of the terminal is not significantly increased, and by setting the independent retransmission timeout for the messages of different service priorities and introducing the queue load status of the alarm host into the timeout calculation, it is ensured that the high-priority alarm can obtain more timely transmission guarantee, and the invalid retransmission of the terminal caused by the busy alarm host is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The flowchart of the first embodiment;

[0028] Figure 2 The schematic diagram of the hierarchical reference dictionary and the extended dictionary;

[0029] Figure 3 is a schematic diagram for encoding;

[0030] Figure 4 is a schematic diagram for CoAP message structure. DETAILED DESCRIPTION

[0031] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0032] The plurality in the present application refers to two or more. In addition, it should be understood that in the description of the present application, the terms "first", "second", and the like are only used for distinguishing purposes of description, and cannot be understood as indicating or implying relative importance, nor can be understood as indicating or implying order.

[0033] In a specific embodiment one, as shown in Figure 1 The present application proposes a method for data interaction between an intelligent alarm information management terminal and an alarm host, comprising the following steps:

[0034] Step one, the intelligent alarm information management terminal and the alarm host are preset with a hierarchical reference dictionary, and an extended dictionary is synchronously maintained according to historical interaction data; the strings in the alarm information are matched with the hierarchical reference dictionary and the extended dictionary, and if the matching is successful, the corresponding dictionary index is output; for the numerical data in the alarm information, the numerical identifier is output and the binary data converted according to the preset point quantization rule is attached; and the compressed data stream is formed together.

[0035] In the present application, the front-end device such as a detector, infrared, door magnet, is connected to the back-end alarm host through a wired connection, the alarm host generates alarm information by summarizing and / or analyzing signals, and transmits the alarm information to the intelligent alarm information management terminal and the server or remote monitoring platform through a network cable and the like. The intelligent alarm information management terminal includes but is not limited to mobile devices such as mobile phones, pads, and can also be a PC. Through the intelligent alarm management terminal, the user can realize real-time understanding of the alarm situation, and the server or remote monitoring platform records the alarm information, so as to realize traceability. In a more specific embodiment, the intelligent alarm information management terminal is a device carried by a security personnel, so that the security personnel can receive alarm information in real time and respond quickly. The alarm host is preferably an edge device.

[0036] The hierarchical reference dictionary is preferably a static dictionary, containing two layers of structure, the first layer storing general category fields in the alarm information, such as area, device type, event type, and the second layer storing specific values corresponding to the categories, such as living room, smoke sensor, fire alarm; the extension dictionary is preferably a dynamic dictionary, managed using the LRU algorithm, when the terminal encounters a new string not contained in the reference dictionary, it is first sent in plaintext form, and the alarm host, after receiving it, synchronizes with the terminal to store the string and its newly assigned dictionary index in the respective extension dictionary, as shown in Figure 2 String matching follows the principle of longest match, and the longest prefix string that can be matched in the dictionary is preferred; for numerical data, such as temperature value 25.7 degrees Celsius, the default fixed-point quantization rule can be to multiply by 10 and take the integer part, resulting in the integer 257, which is then converted to a 16-bit binary number; when encoding, a reserved special dictionary index is first output as a numerical identifier, such as FFFF, followed by the 16-bit binary data, and upon reading the identifier, the receiving party knows that the subsequent data is numerical rather than a dictionary index, as shown in Figure 3 In an optional embodiment, the binary data is further encrypted, and the encryption methods include but are not limited to symmetric encryption and asymmetric encryption.

[0037] Step two, based on the pre-shared key and the message sequence number and timestamp bound to the alarm information service priority level, a transformation key is generated; using the transformation key, a shift amount is derived, and a cyclic bit shift operation is performed on the dictionary index in the compressed data stream, resulting in an encrypted compressed data stream, wherein the numerical identifier and the binary data are not involved in the shift operation;

[0038] The HMAC-SHA256 algorithm is preferably used, the pre-shared key is used as the key, and the concatenation of the message sequence number and the timestamp is used as the message, to calculate a 256-bit hash value as the transformation key; the last 8 bits of the hash value are taken, converted to an integer, and then taken modulo 16 to obtain an integer between 0 and 15 as the shift amount; for each 16-bit dictionary index in the compressed data stream, a cyclic left or right shift of the number of bits specified by the shift amount is performed, while the numerical identifier FFFF and the binary data that follow it remain unchanged.

[0039] Step three, the terminal places the encrypted compressed data stream in the payload part of the CoAP message, and sets a custom Option in the Option field of the CoAP message containing the service priority level and the message sequence number;

[0040] The generated encrypted compressed data stream is directly filled into the Payload area of the CoAP message; a private Option number, such as 2050, is selected as a custom Option in the CoAP protocol; the value of the Option is one byte, in which the high 2 bits are used to represent the service priority level, such as 00 for high, 01 for medium, and 10 for low, and the last 6 bits are used to store the message sequence number of the current priority.

[0041] Step four, the terminal maintains independent round-trip time RTT and retransmission timeout RTO for different service priority levels respectively; after sending the CoAP message, if no alarm host acknowledgement ACK is received within the RTO corresponding to the current service priority level, retransmission is performed; when the ACK message returned by the alarm host is received, the RTT and RTO corresponding to the service priority level are updated according to the reception time of the ACK and the queue load factor of the alarm host carried in the ACK.

[0042] For each service priority level, when the ACK is received, the SampleRTT is first calculated, which is equal to the ACK reception time minus the message sending time; then the SRTT is updated, which is equal to the old SRTT multiplied by the coefficient a plus the SampleRTT multiplied by (1-a); then the RTTVAR is updated; the new RTO is calculated, which in one embodiment is equal to the SRTT plus four times the RTTVAR, and additionally adds an adjustment term proportional to the queue load factor L of the alarm host, which is returned by the alarm host in the custom Option of the ACK message, so that the RTO can reflect the real-time processing capacity of the alarm host.

[0043] In a more specific embodiment, the hierarchical reference dictionary includes a static core dictionary layer and a semi-static application dictionary layer; the static core dictionary layer contains general vocabularies that are fixed and unchanged in the alarm service; the semi-static application dictionary layer contains special vocabularies that remain unchanged within a period of time in a specific application scenario.

[0044] The hierarchical design can improve compression efficiency and adaptability. For example, the static core dictionary layer can contain general vocabularies in the fire alarm system, such as fire alarm, fault, start, and recovery, which are applicable in all projects. The semi-static application dictionary layer can contain vocabularies such as A, B, fire pump, and smoke exhaust fan for a specific project, such as a large shopping mall project, which are stable within the project but not applicable in other projects such as chemical plants.

[0045] In a more specific embodiment, the preset point quantization rule is: multiplying the numerical data by a preset quantization factor, rounding, and converting the obtained integer into a 16-bit length two's complement form.

[0046] Efficiently converting the floating point number into a fixed-length integer can reduce the data amount. For example, a temperature sensor reports a value of 25.43 degrees Celsius, which is multiplied by a quantization factor of 100 to obtain an integer of 2543. The integer 2543 is converted into a 16-bit two's complement form of 0000100111101111, thereby preserving the two decimal precision and uniformly converting the original floating point number into 16-bit data that is easy to process and transmit.

[0047] In order to ensure that each message is transformed using a unique key, the security is enhanced. In a more specific embodiment, the message sequence number and the timestamp based on the binding of the pre-shared key and the alarm information service priority level are used to generate a transformation key, specifically:

[0048] The pre-shared key is used as the main key of the HMAC-SHA256 hash function, and the message formed by concatenating the message sequence number and the timestamp is used as the input. The obtained 256-bit hash value is the transformation key.

[0049] Suppose the pre-shared key is a fixed 128-bit key, the current message sequence number is 105, and the timestamp is 1678886400. Concatenate 105 and 1678886400 into a data string, and use the pre-shared key as the key of HMAC-SHA256 to calculate the data string, generating a 256-bit hash value, which is the dynamic transformation key for this message transmission.

[0050] In a more specific embodiment, the dictionary index in the compressed data stream is subjected to a cyclic bit shift operation to obtain an encrypted compressed data stream, specifically:

[0051] The value of the lowest 4 bits of the transformation key is used as the shift amount;

[0052] And each 12-bit length dictionary index in the compressed data stream is subjected to a left cyclic bit shift specified by the shift amount.

[0053] This embodiment provides a lightweight data scrambling encryption. For example, if the lowest 4 bits of the generated dynamic transformation key are 1011, the corresponding decimal value is 11, which is the shift amount. For a 12-bit dictionary index 000100100011 in the compressed stream, a left cyclic shift of 11 times is performed to obtain a new data 110001001000, thereby confusing the original data without increasing the calculation overhead.

[0054] In a more specific embodiment, the custom Option set in the Option field of a CoAP message uses a reserved Option number 2048; the value of the custom Option is a 2-byte field, where the high 2 bits are used to represent the traffic priority level and the low 14 bits are used to represent the message sequence number.

[0055] The CoAP message structure is shown in Figure 4 For a high-priority traffic message, its priority level can be represented as binary 10, and if its message sequence number is 5000, its 14-bit binary representation is 01001110001000. These two binary numbers are combined into a 16-bit, i.e. 2-byte data 1001001110001000, which is sent as the Option value together with the Option number 2048 in the Option field of the CoAP message.

[0056] In a more specific embodiment, the RTT and RTO for the corresponding traffic priority level are updated according to the reception time of the ACK and the alarm host queue load factor carried therein, specifically:

[0057] Upon receiving the alarm host acknowledgement ACK message, the sample round-trip time SampleRTT of the current message is calculated;

[0058] The round-trip time deviation RTTVAR is updated according to the formula is the weight coefficient;

[0059] The weighted average round-trip time SRTT is updated according to the formula

[0060] The retransmission timeout RTO is updated according to the formula wherein is equal to the alarm host queue load factor multiplied by a preset time coefficient, , is the weight coefficient;

[0061] SRTT is the average round-trip time, is the SRTT value before updating, is the updated SRTT value, RTTVAR is the round-trip time deviation, is the RTTVAR value before updating, is the new RTTVAR value calculated this time, RTO new is the updated retransmission timeout RTO value.

[0062] Preferably ,​​ Taking this preferred weighting coefficient as an example, let's assume that the current weighted average round-trip time of a certain priority service is... Round-trip time deviation is 100 milliseconds. The original value was 15 milliseconds. The measured sample round-trip time (SampleRTT) was 120 milliseconds. Therefore, the new... The new one is 16.25 milliseconds. The timeout is 102.5 milliseconds. If the alarm host load factor is 0.5 and the preset time coefficient is 10 milliseconds, then the load adjustment time is 5 milliseconds, and the calculated new retransmission timeout is... The timeout is 172.5 milliseconds, which allows the retransmission strategy to more accurately reflect the current network congestion and the processing capacity of the alarm host.

[0063] In a second specific embodiment, a data interaction system between an intelligent alarm information management terminal and an alarm host is provided, comprising:

[0064] The compression unit, intelligent alarm information management terminal, and alarm host are pre-set with a hierarchical reference dictionary and synchronously maintain an extended dictionary based on historical interaction data; the string in the alarm information is matched with the hierarchical reference dictionary and the extended dictionary, and if the match is successful, the corresponding dictionary index is output; for numerical data in the alarm information, a numerical identifier is output and binary data converted according to a preset point quantization rule is appended; together they form a compressed data stream;

[0065] The encryption unit generates a transformation key based on the message sequence number and timestamp bound to the pre-shared key and the priority level of the alarm information service; it uses the transformation key to derive the shift amount and performs a cyclic bit shift operation on the dictionary index in the compressed data stream to obtain an encrypted compressed data stream, wherein the numerical identifier and the binary data do not participate in the shift operation;

[0066] The data packet generation unit, wherein the terminal places the encrypted and compressed data stream in the payload portion of the CoAP message, and sets a custom Option containing the service priority level and message sequence number in the Option field of the CoAP message;

[0067] The transmission unit, wherein the terminal maintains independent round-trip time (RTT) and retransmission timeout (RTO) for different service priority levels; after sending the CoAP message, if no ACK message is received from the alarm host within the RTO corresponding to the current service priority level, a retransmission is performed; when an ACK message is received from the alarm host, the RTT and RTO of the corresponding service priority level are updated according to the reception time of the ACK and the alarm host queue load factor carried therein.

[0068] Those skilled in the art can clearly understand the application by the description of the above embodiments that the application can be implemented by means of software and the necessary universal hardware platforms. Based on such an understanding, the technical solutions of the application can be embodied in the form of a software product, and the computer software product can be stored in a storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, and the like, and includes a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, and the like) execute the methods described in each embodiment or some parts of the embodiments of the application.

[0069] Each of the embodiments in the specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other. Each of the embodiments focuses on the difference from other embodiments. In particular, for the system or the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the related parts can be referred to the part of the method embodiment. The above-described system and system embodiment are merely illustrative, and the units described as separate components can be or can not be physically separated, and the components displayed as units can be or can not be physical units, that is, they can be located in one place, or can be distributed on multiple network units. According to the actual needs, some or all of the modules can be selected to achieve the purpose of the embodiment. Those skilled in the art can understand and implement it without creative labor.

[0070] The method for providing commodity object information and the electronic device provided by the application are described in detail above, and the principles and implementation manners of the application are described by applying specific examples. The above embodiment is only used to help understand the method of the application and its core idea; meanwhile, for those skilled in the art, according to the idea of the application, the specific implementation manner and application range can be changed. In conclusion, the content of the specification should not be understood as a limitation of the application.

Claims

1. A method for data interaction between an intelligent alarm information management terminal and an alarm host, characterized in that, The method comprises the following steps: The intelligent alarm information management terminal and the alarm host preset a hierarchical reference dictionary, and synchronously maintain an extended dictionary according to historical interaction data; the strings in the alarm information are matched with the hierarchical reference dictionary and the extended dictionary, and if the matching is successful, the corresponding dictionary index is output; for the numerical data in the alarm information, the numerical identifier and the binary data converted according to a preset point quantization rule are output; Commonly form a compressed data stream; Based on the message sequence number and the timestamp bound to the pre-shared key and the alarm information service priority level, a transform key is generated; The transform key is used to derive a shift amount, and a cyclic bit shift operation is performed on the dictionary index in the compressed data stream to obtain an encrypted compressed data stream, wherein the numerical identifier and the binary data do not participate in the shift operation; The terminal places the encrypted compressed data stream in the payload part of the CoAP message, and sets a custom Option in the Option field of the CoAP message, wherein the custom Option contains the service priority level and the message sequence number. The terminal maintains independent round trip time (RTT) and retransmission timeout (RTO) for different service priority levels; after sending the CoAP message, if no acknowledgement (ACK) is received from the alarm host within the RTO corresponding to the current service priority level, retransmission is performed; when the ACK message returned by the alarm host is received, the RTT and the RTO of the corresponding service priority level are updated according to the reception time of the ACK and the alarm host queue load factor carried in the ACK.

2. The data interaction method of claim 1, wherein, The hierarchical reference dictionary comprises a static core dictionary layer and a semi-static application dictionary layer; the static core dictionary layer contains general vocabularies that are fixed and unchanged in the alarm service; and the semi-static application dictionary layer contains special vocabularies that remain unchanged in a period of time in a specific application scenario.

3. The data interaction method of claim 1, wherein, The preset point quantization rule is that the numerical data is multiplied by a preset quantization factor, and then the obtained integer is converted into a 16-bit length binary complement form.

4. The data interaction method of claim 1, wherein, The transform key is generated based on the message sequence number and the timestamp bound to the pre-shared key and the alarm information service priority level, and specifically: The pre-shared key is used as the main key of the HMAC-SHA256 hash function, and the message formed by concatenating the message sequence number and the timestamp is used as the input, and the obtained 256-bit hash value is the transform key.

5. The data interaction method of claim 1, wherein, The cyclic bit shift operation is performed on the dictionary index in the compressed data stream to obtain the encrypted compressed data stream, and specifically: The lowest 4 bits of the transform key are used as the shift amount; And for each 12-bit length dictionary index in the compressed data stream, a left cyclic bit shift specified by the shift amount is performed.

6. The data interaction method of claim 1, wherein, The custom Option set in the Option field of the CoAP message uses the reserved Option number 2048; the value of the custom Option is a 2-byte field, wherein the high 2 bits are used to represent the service priority level, and the low 14 bits are used to represent the message sequence number.

7. The data interaction method of claim 1, wherein, According to the receiving time of the ACK and the alarm host queue load factor carried therein, the RTT and RTO of the corresponding service priority level are updated, specifically: After receiving the alarm host confirmation ACK message, the sample round trip time SampleRTT of this message is calculated; According to the formula updating a round-trip time variation RTTVAR; According to the formula update the smoothed round-trip time SRTT; According to the formula updating a retransmission timeout RTO, wherein is equal to the alert host queue load factor multiplied by a preset time coefficient, 、 is a weight coefficient; SRTT is the average round trip time, SRTTold is the SRTT value before the update, SRTTnew is the SRTT value after the update, RTTVAR is the round trip time variation, RTTVARold is the RTTVAR value before the update, RTTVARnew is the new RTTVAR value calculated this time, RTO new RTOnew is the new retransmission timeout RTO value after the update.

8. The intelligent alarm information management terminal and alarm host data interaction system is characterized in that, Comprise: The compression unit, the intelligent alarm information management terminal and the alarm host preset a hierarchical reference dictionary, and a extended dictionary is synchronously maintained according to historical interaction data; The string in the alarm information is matched with the hierarchical reference dictionary and the extended dictionary, and the corresponding dictionary index is output if the matching is successful; For the numerical value type data in the alarm information, the numerical value identifier and the binary data converted according to the preset point quantization rule are output; Commonly form a compressed data stream; The encryption unit generates a transformation key based on the pre-shared key, the message sequence number and the time stamp bound with the alarm information service priority level; The shift amount is derived by using the transformation key, and the dictionary index in the compressed data stream is subjected to a cyclic bit shift operation to obtain an encrypted compressed data stream, wherein the numerical value identifier and the binary data do not participate in the shift operation; The data packet generation unit places the encrypted compressed data stream in the payload part of the CoAP message, and sets a custom Option containing the service priority level and message sequence number in the Option field of the CoAP message; The transmission unit, the terminal maintains independent round trip time RTT and retransmission timeout RTO for different service priority levels; After sending the CoAP message, if the alarm host confirmation ACK is not received within the RTO corresponding to the current service priority level, retransmission is performed; When the confirmation ACK message returned by the alarm host is received, according to the receiving time of the ACK and the alarm host queue load factor carried therein, the RTT and RTO of the corresponding service priority level are updated.

9. The data interaction system of claim 8, wherein, The hierarchical reference dictionary comprises a static core dictionary layer and a semi-static application dictionary layer; The static core dictionary layer contains fixed and unchanged general vocabulary in the alarm service; The semi-static application dictionary layer contains special vocabulary that remains unchanged in a period of time in a specific application scenario.

10. The data interaction system of claim 8, wherein, The preset point quantization rule is: multiply the numerical value type data by a preset quantization factor, take the integer, and then convert the obtained integer into a 16-bit length binary complement form.

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