Aerial equipment EPC coding encryption method based on improved Fesitel

Abstract

The invention relates to the field of coding, in particular to an aviation equipment EPC coding encryption method based on improved Fesitel, and the method specifically comprises the following steps: S1, mapping an aviation equipment code to an EPC code; s2, using an improved Fesitel network to encrypt the EPC code of the aviation equipment, comprising the following sub-steps: S21, performing segmentation scrambling on the EPC code to obtain a left half part and a right half part; s22, generating a pseudo-random sequence by using a pseudo-random number generator; s23, obtaining a binary number as a round key according to the pseudo-random sequence, and S24, carrying out iterative encryption to obtain a final encryption result. According to the method, the traditional aviation equipment code is mapped to the EPC code, and the improved Feistel network is used for encryption, so that the uniformity and traceability of information can be enhanced, and the standard format of the EPC code is reserved while the data security is ensured.

Description

Technical Field

[0001] The invention relates to the field of coding, and in particular to an EPC coding encryption method for aviation equipment based on improved Fesitel. Background Art

[0002] At present, there are a lot of commonalities between military and civil aviation equipment, but because the two use different coding standards, information exchange is complex and difficult, which in turn affects the allocation of materials and operational efficiency. With the rapid development of the Internet of Things, the channels for information exchange have increased significantly. EPC (Electronic Product Code) has played an important role in the global circulation of goods as an efficient way of interaction. If the traditional aviation equipment code can be mapped to the EPC code, it can not only enhance the uniformity and traceability of information, but also simplify the interoperability code conversion of military and civilian equipment.

[0003] However, the existing EPC code has deficiencies in security and cannot fully protect the security of sensitive information. Direct code mapping may bring the risk of information leakage, so improving the security of EPC code has become an urgent problem to be solved. Traditional encryption algorithms, such as AES and DES, can provide high-intensity encryption protection, but they are usually not suitable for structured data such as EPC code, because when these algorithms encrypt the encoded data, the code will be converted into an unreadable ciphertext format and cannot be directly used for information exchange under the encoding standard.

[0004] Feistel network, also known as Feistel structure, is a classic symmetric encryption model, widely used in various block ciphers such as DES (Data Encryption Standard). Feistel network has been widely used in data encryption and confidential communication due to its unique encryption structure and wide applicability. It divides the data into two parts, processes the data alternately in each round of encryption, and performs complex operations with pseudo-random sequences, so that the encryption process can ensure high security. The iterative characteristics of Feistel network make it highly symmetric during encryption and decryption, so it is possible to use Feistel network to implement format-preserving encryption (FPE).

[0005] Therefore, if the Feistel network can be improved and applied to the encryption of EPC codes of aviation equipment, the standard format of EPC codes can be retained while ensuring data security. This structured encryption method not only improves information security, but also simplifies the code conversion process of military and civilian aviation equipment, optimizes overall operational efficiency and information traceability, and thus provides higher security for the aviation equipment management system. Summary of the invention

[0006] In order to overcome the defects of the prior art, the purpose of the present invention is to convert the aviation equipment code into the EPC code standard format and perform format-preserving encryption, which not only simplifies the code conversion process but also improves the security of information.

[0007] The present invention provides an aviation equipment EPC coding encryption method based on improved Fesitel, and the specific steps are as follows:

[0008] S1, mapping of aircraft equipment code to EPC code;

[0009] The aviation equipment code consists of the classification code, the base name code and the variety code, each of which is represented by 0-9 or letters. The EPC code consists of the header, domain name management, object classification and serial number, each of which is represented by binary.

[0010] When the aircraft equipment code is mapped to the EPC code, the header of the EPC code is determined according to the version of the converted EPC code;

[0011] The classification code in the aviation equipment code has two digits each representing a primary classification, a total of 4 digits, which are mapped to the object classification part of the EPC code;

[0012] The base name code in the aircraft equipment code is 5 digits in total, of which 4 digits are mapped to the domain name management of the EPC code, and 1 digit is mapped to the remaining position of the object classification part of the EPC code;

[0013] The variety code in the aircraft equipment code is 9 digits in total, of which the 1st and 2nd digits are mapped to the domain name management of the EPC code; the 3rd digit is mapped to the object classification of the EPC code, and the remaining 4-9 digits of the variety code are mapped to the serial number of the EPC code;

[0014] S2, using the improved Fesitel network to encrypt the EPC code of aviation equipment;

[0015] S21, segmenting the EPC code;

[0016] The EPC-encoded version number is used as the scrambling code tweak, and the remaining bit data is divided equally into the left half and the right half;

[0017] S22, generating a pseudo-random sequence;

[0018] The key, tweak and the current iteration round are combined as the seed and the HMAC pseudo-random number generator is used to generate a pseudo-random sequence s. The HMAC pseudo-random number generator is specifically:

[0019]

[0020] Where K is the key; seed is the seed obtained by concatenating the key K, the scrambling code tweak and the current iteration round index using a string; the initial value of the iteration round index is 1, and the index value increases by 1 after each iteration; the key K and the seed seed are used as input; H() is a hash function, ipad and opad are the padding constants of the inner and outer layers respectively, which are used to scramble the key; ∥ is the standard string concatenation operator;

[0021] S23, obtaining a binary number as the round key F;

[0022] Each bit of the pseudo-random sequence s is 0-9. After intercepting the pseudo-random sequence and converting it into a binary number, the binary number with the same number of digits as the left half or the right half is intercepted as the round key F;

[0023] S24, iterative encryption;

[0024] Left is XORed bit by bit with F to get the intermediate result temp. At this time, left is replaced by right, and right is replaced by temp to complete an iteration. After a specified number of iterations, tweak, left and right are reconnected to get the final encryption result.

[0025] Preferably, the aviation equipment code is 18 bits and the EPC code is 96 bits.

[0026] Preferably, the specific process of mapping the S1 aviation equipment code to the EPC code is:

[0027] When the aircraft equipment code is mapped to the EPC code, the header of the EPC code is 8 bits, which is determined by the version of the EPC code being converted;

[0028] The classification code in the aviation equipment coding adopts one-level and two-level classification. Each two bits represent the first-level classification, and the value is 01-99. The number of schemes that can be represented by the four-bit classification code is 99×99=9801, and the corresponding binary digit is 14 bits. The object classification part of the EPC code has a total of 24 bits of binary code, which is mapped to the object classification part of the EPC code. After the mapping is completed, there are 10 bits left;

[0029] In the aviation equipment code, the base name code is 5 digits in total. The base name code is composed of Arabic numerals 0 to 9 and uppercase letters except I and O. There are 34 schemes for the value of each digit, and each scheme is represented by a binary number. In order to distinguish, each digit of the base name code is represented by a 6-bit binary code. The domain name management in the EPC code is 28 digits, and the object classification is 10 digits. The first 4 digits of the base name code are mapped to the domain name management in the EPC code, and the last base name code is mapped to the EPC object classification. Therefore, after the mapping is completed, in the EPC code, the domain name management has 4 binary digits left, and the object classification has 4 binary digits left;

[0030] In the aviation equipment coding, the variety code has a total of 9 digits, of which the 1st and 2nd digits are fixed values ​​86 or 87 and are used to distinguish the coding agency. Therefore, the 1st and 2nd digits of the variety code can be represented in the EPC code with only 1 binary bit. The 1st and 2nd digits of the variety code are mapped to the domain name management office of the EPC code. At this time, there are 3 binary digits left in the domain name management office of the EPC code; the 3rd digit of the variety code has a specific meaning in the aviation equipment coding, including {0~9,M,S}, a total of 12 schemes, which are distinguished by 4-bit binary coding, so the 3rd digit is mapped to the object classification of the EPC code; the remaining 4-9 digits of the variety code are the variety serial code, which is composed of Arabic numerals 0~9 and uppercase letters except I and O. Each character of the 4-9 digits of the variety serial code is still represented by a 6-bit binary code. Therefore, the variety serial code requires a total of 36 binary bits, and the serial number part of the EPC code is 36 bits. The variety serial code is completely mapped to the serial number of the EPC code.

[0031] Preferably, in S21, the first 8 bits of the version number of the EPC code are used as the scrambling code tweak, and the remaining 88 bits of data are equally divided into a left half left and a right half right, wherein the first 44 bits are left and the last 44 bits are right.

[0032] Preferably, in S22, the hash function is SHA-256, and the values ​​of ipad and opad are 0x36 and 0x5c respectively.

[0033] Preferably, in S23, each bit of the pseudo-random sequence s has a value of 0-9, and an 8-bit binary number is used to represent the different values ​​of each bit. The first 6 bits of the pseudo-random sequence are intercepted and converted into binary to obtain a 48-bit binary number, and then the first 44 bits of the binary number are intercepted as the round key F.

[0034] Preferably, the decryption process further includes: using the same pseudo-random number generation mechanism and XOR operation as encryption, reversely executing the operation of the Feistel network, and gradually restoring the plaintext.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. The present invention maps the traditional aviation equipment code to the EPC code, which can not only enhance the uniformity and traceability of information, but also simplify the interoperable code conversion of military and civilian equipment.

[0037] 2. After improving the existing Feistel network, the present invention is applied to the encryption of EPC codes of aviation equipment, thereby ensuring data security while retaining the standard format of EPC codes. This structured encryption method improves the security of information and provides higher security for the aviation equipment management system. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a flow chart of the EPC coding encryption method for aviation equipment based on the improved Fesitel;

[0039] Figure 2 This is an example diagram of the mapping process from aircraft equipment code to EPC code;

[0040] Figure 3 It is a schematic diagram of the improved Feistel network coding process. DETAILED DESCRIPTION

[0041] In order to better understand the technical solution of the present invention, the specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings need not be drawn to scale unless otherwise specified.

[0042] The present invention proposes an aviation equipment EPC coding encryption method based on improved Fesitel, such as Figure 1 As shown, the specific implementation steps are as follows:

[0043] S1, aircraft equipment code is mapped to EPC code.

[0044] The aviation equipment code consists of a classification code, a reference name code and a variety code, each of which is represented by Arabic numerals 0 to 9 or capital letters. The EPC code consists of a header, a domain name management, an object classification and a serial number, each of which is represented in binary. Currently, the aviation equipment code is 18 bits, and the EPC code in this embodiment is 96 bits.

[0045] When the aircraft equipment code is mapped to the EPC code, the EPC code header is determined according to the converted EPC code version. Currently, the EPC code header is usually 8 bits, which are used to indicate the EPC code version.

[0046] The classification code in the aviation equipment coding adopts one-level and two-level classification. Each two bits represent the first-level classification, and the value is 01-99. The number of schemes that can be represented by the four-bit classification code is 99×99=9801, and the corresponding binary digit is about 14 bits (log29801≈14), which is mapped to the object classification part of the EPC code. The object classification part of the EPC code has a total of 24 bits of binary code, and 10 bits remain after the mapping is completed.

[0047] In the aviation equipment code, the base name code is 5 digits in total. The base name code is composed of Arabic numerals 0 to 9 and uppercase letters except "I" and "O". There are 34 options for each value. Each option is represented by a binary number, and at least six binary codes are required to distinguish. Therefore, each digit of the base name code is represented by a 6-bit binary code. The complete base name has a total of 5 digits, and a total of 30 binary codes are required. However, in the EPC code, the domain name management is only 28 digits, so the last base name code is placed in the EPC object classification. After the mapping is completed, in the EPC code, the domain name management has 4 binary digits remaining, and the object classification has 4 binary digits remaining.

[0048] In the aviation equipment coding, the variety code has a total of 9 digits, of which the 1st and 2nd digits are fixed values ​​86 or 87 to distinguish the coding agency. Therefore, the 1st and 2nd digits of the variety code can be represented in the EPC code with only 1 binary digit. The 1st and 2nd digits of the variety code are mapped to the domain name management office of the EPC code. At this time, there are 3 binary digits left in the domain name management office of the EPC code. The 3rd digit of the variety code has a specific meaning in the aviation equipment coding, including {0~9, M, S}, a total of 12 schemes, which require 4 binary digits to distinguish. Therefore, the 3rd digit scheme is mapped to the object classification of the EPC code, and the remaining 4 binary digits of the object classification are used. The remaining 4-9 digits of the variety code are the variety serial code, which consists of Arabic numerals 0~9 and uppercase letters except "I" and "O". The same binary code is used as the base name code, that is, each character of the 4-9 digits of the variety serial code is still represented by a 6-bit binary code, so the variety serial code requires a total of 36 binary digits. The serial number part of the EPC code is 36 bits, and the variety serial code can be completely mapped to the serial number of the EPC code.

[0049] The following takes the aviation equipment code 162032ZD5871A45ZF6 as an example, and the EPC code uses the 96-bit EPC-96TYPEI as an example. The specific mapping process is as follows Figure 2 shown.

[0050] First, for the reference name code and the variety serial code in the variety code, set the corresponding relationship between the binary code and the Arabic numerals 0 to 9 and the capital letters except "I" and "O", as shown in Table 1. The specific scheme is as follows:

[0051] Table 1

[0052] Code 0 1 2 3 ... 9 A B C ... Y Z Dictionary Values 0 1 2 3 ... 9 10 11 12 ... 32 33

[0053] Taking the letter Z as an example, its corresponding dictionary value is 33, which is the largest. Its binary value can be expressed as 100001. Each bit of the variety sequence code in the reference name code and variety code is converted according to Table 1. If it is less than six bits, 0 is added to the first bit.

[0054] For the third digit of the variety code, set the corresponding relationship between the binary code and {0-9, M, S}, as shown in Table 2. The specific scheme is as follows:

[0055] Table 2

[0056] Code 0 1 2 ... 9 M S Dictionary Values 0 1 2 ... 9 10 11

[0057] The third digit of the variety code has 12 options in total and is distinguished using 4-bit binary code.

[0058] Secondly, the EPC-encoded header is given according to the EPC-96TYPE I standard.

[0059] Next, the aviation equipment classification code is 1620. It can be seen that the first-level classification is 16 and the second-level classification is 20. Convert 16 and 20 to the corresponding binary 00100000010100, which is mapped to the last 14 bits of the object classification of the EPC code.

[0060] Then, the aircraft equipment base name code is 32ZD5. According to the corresponding relationship in Table 1, the corresponding values ​​of 32ZD5 are 3, 2, 33, 13, and 5, respectively. Therefore, the value is converted into the corresponding binary code 000011000010100001001101000101. The binary code of the first 4 bits of the code is mapped to the last 24 bits of the EPC code domain name management part, and the binary code of the fifth base name code is mapped to the first 6 bits of the EPC code object classification.

[0061] Finally, the aircraft equipment variety code is 871A45ZF6, the first two digits of which are the coding agency code 87, corresponding to the binary value 1, mapped to the 4th digit of the EPC code domain name management part, the 3rd digit of the variety code is 1, according to Table 2, the corresponding value is 1, so the corresponding binary value is 0001, mapped to the 7th to 10th digits of the EPC code object classification, the remaining sequence code A45ZF6 also obtains the corresponding value corresponding to the binary according to Table 1, and the remaining sequence code corresponding to the binary is completely mapped to the serial number part of the EPC code.

[0062] When all mappings are completed, the aircraft equipment EPC code is obtained. There are still 3 redundant binary bits in the aircraft equipment EPC code, which can be used for subsequent expansion of the aircraft equipment code mapping to the EPC code, ensuring the scalability of the aircraft equipment code to the EPC code mapping.

[0063] S2, use the improved Fesitel network to encrypt the EPC code of aviation equipment.

[0064] The traditional Feistel network does not pay attention to the format of plaintext and ciphertext during the encryption process, but disrupts the order of data through multiple rounds of iterative exchanges of left and right groups. However, after the EPC code is encrypted, it is necessary to ensure that the EPC code is still in binary format and the length remains unchanged. Therefore, the present invention combines the format-preserving encryption algorithm with the traditional Feistel network, which can maintain the format integrity of the EPC code during the encryption process. At the same time, because the header of the EPC code contains important version number information and does not contain aviation equipment coding information, the 96-bit binary data of the EPC code is innovatively split into tweak (scrambling code), left (left half) and right (right half), among which tweak is used to solve the conflict problem that may be caused by local encryption. The specific steps are:

[0065] S21, segment the EPC code.

[0066] The first 8 bits of the EPC code version number are used as a scrambling code (tweak), and the remaining 88 bits of data are divided into a left half (left) and a right half (right), wherein the first 44 bits are left and the last 44 bits are right. The improved Fesitel network introduces tweak so that each EPC code introduces the external information of the version number in the encryption process, ensuring that when the aviation equipment code uses different versions of EPC codes, even if the EPC code parts are the same, the same ciphertext will not be generated, avoiding encryption conflicts and solving the conflict problem that may be caused by local encryption. In the present invention, we use the first 8 bits of the EPC code version number as tweak, and this part of the data is not encrypted during the encryption process, but is kept intact as an auxiliary parameter to participate in the encryption operation. In this way, it can be ensured that the specific coding part (version number) remains consistent after encryption and is not modified. The remaining 88 bits of data are divided into left and right, wherein the first 44 bits are left and the last 44 bits are right, for subsequent encryption processing.

[0067] S22, generate a pseudo-random sequence.

[0068] Combine the key, tweak and the current iteration round as the seed and use the HMAC (Hash-based Message Authentication Code) pseudo-random number generator to generate a pseudo-random sequence. The HMAC pseudo-random number generator is specifically:

[0069]

[0070] Wherein, K is the key; seed is the seed obtained by concatenating the key K, the scrambling code tweak and the current iteration round index using a string; the initial value of the iteration round index is 1, and the index value increases by 1 after each iteration; the key K and the seed seed are used as input; H() is a hash function. The hash function selected in this embodiment is SHA-256, which ensures the security of the message and the key after double-layer hashing; ipad and opad are the padding constants of the inner and outer layers respectively. In this embodiment, the standard values ​​are 0x36 and 0x5c, respectively, which are used to scramble the key; ∥ is the concatenation operator of the standard string. The HMAC algorithm performs an exclusive or operation with the key K and the two padding constants ipad and opad respectively, and performs two hash operations in combination with the seed seed, thereby generating a pseudo-random sequence s with high randomness and security. The length of the pseudo-random sequence s is determined by the output length of the hash function, such as the output of SHA-256 is 32 bytes. In this embodiment, the seed seed changes according to the regularity of the iteration round, which ensures that the pseudo-random sequence s generated each time is different, and that the corresponding pseudo-random sequence s can be generated during decryption.

[0071] S23, obtain a binary number as the round key F.

[0072] The HMAC pseudo-random number generator generates a pseudo-random sequence s, where each bit of the pseudo-random sequence s takes a value of 0-9, so an 8-bit binary number can be used to represent the different values ​​of each bit. The first 6 bits of the pseudo-random sequence are intercepted, converted to binary to obtain a 48-bit binary number, and the first 44 bits of the binary number are intercepted as the round key F. This ensures that in each round of iteration, the generated round key F is unpredictable and will not be repeated between different rounds.

[0073] S24, iterative encryption.

[0074] Left is XORed with F bit by bit to get the intermediate result temp. At this time, replace left with right, and right with temp, completing one iteration. The encryption process is as follows: Figure 3 After multiple rounds of iterations, tweak, left, and right are reconnected to obtain the final encryption result.

[0075] Through the improved Feistel structure, the present invention not only retains the original format of the EPC code, but also improves the security and anti-attack performance of data encryption.

[0076] In the decryption process, the same pseudo-random number generation mechanism and XOR operation as encryption are used to reverse the operation of the Feistel network and gradually restore the plaintext. While ensuring security, efficient data decryption is achieved and the decrypted result is ensured to be consistent with the original data before encryption.

[0077] Finally, it should be noted that the above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An improved Fesitel-based EPC coding encryption method for aviation equipment, characterized in that: It includes the following steps: S1, mapping of aircraft equipment code to EPC code; The aviation equipment code consists of the classification code, the base name code and the variety code, each of which is represented by 0-9 or letters. The EPC code consists of the header, domain name management, object classification and serial number, each of which is represented by binary. When the aircraft equipment code is mapped to the EPC code, the header of the EPC code is determined according to the version of the converted EPC code; The classification code in the aviation equipment code has two digits each representing a first-level classification, a total of 4 digits, which are mapped to the object classification part of the EPC code; The base name code in the aircraft equipment code is 5 digits in total, of which 4 digits are mapped to the domain name management of the EPC code, and 1 digit is mapped to the remaining position of the object classification part of the EPC code; The variety code in the aircraft equipment code is 9 digits in total, of which the 1st and 2nd digits are mapped to the domain name management of the EPC code; the 3rd digit is mapped to the object classification of the EPC code, and the remaining 4-9 digits of the variety code are mapped to the serial number of the EPC code; S2, using the improved Fesitel network to encrypt the EPC code of aviation equipment; S21, segmenting the EPC code; The EPC-encoded version number is used as the scrambling code tweak, and the remaining bit data is divided equally into the left half and the right half; S22, generating a pseudo-random sequence; The key, tweak and the current iteration round are combined as the seed and the HMAC pseudo-random number generator is used to generate a pseudo-random sequence s. The HMAC pseudo-random number generator is specifically: s=HMAC(K,seed)=H((K⊕opad)∥H((K⊕ipad)∥seed)) (1) Where K is the key; seed is the seed obtained by concatenating the key K, the scrambling code tweak and the current iteration round index using a string; the initial value of the iteration round index is 1, and the index value increases by 1 after each iteration; the key K and the seed seed are used as input; H() is a hash function, ipad and opad are the padding constants of the inner and outer layers respectively, which are used to scramble the key; ∥ is the standard string concatenation operator; S23, obtaining a binary number as the round key F; Each bit of the pseudo-random sequence s is 0-9. After intercepting the pseudo-random sequence and converting it into a binary number, the binary number with the same number of digits as the left half or the right half is intercepted as the round key F; S24, iterative encryption; Left is XORed bit by bit with F to get the intermediate result temp. At this time, left is replaced by right, and right is replaced by temp to complete an iteration. After a specified number of iterations, tweak, left and right are reconnected to get the final encryption result.

2. The improved Fesitel-based EPC coding encryption method for aviation equipment according to claim 1 is characterized in that: The aviation equipment code is 18 bits and the EPC code is 96 bits.

3. The aviation equipment EPC coding encryption method based on improved Fesitel according to claim 2 is characterized in that: The specific process of mapping the S1 aviation equipment code to the EPC code is as follows: When the aircraft equipment code is mapped to the EPC code, the header of the EPC code is 8 bits, which is determined by the version of the EPC code being converted; The classification code in the aviation equipment coding adopts one-level and two-level classification. Each two bits represent the first-level classification, and the value is 01-99. The number of schemes that can be represented by the four-bit classification code is 99×99=9801, and the corresponding binary digit is 14 bits. The object classification part of the EPC code has a total of 24 bits of binary code, which is mapped to the object classification part of the EPC code. After the mapping is completed, there are 10 bits left; In the aviation equipment code, the base name code is 5 digits in total. The base name code is composed of Arabic numerals 0 to 9 and uppercase letters except I and O. There are 34 schemes for the value of each digit, and each scheme is represented by a binary number. In order to distinguish, each digit of the base name code is represented by a 6-bit binary code. The domain name management in the EPC code is 28 digits, and the object classification is 10 digits. The first 4 digits of the base name code are mapped to the domain name management in the EPC code, and the last base name code is mapped to the EPC object classification. Therefore, after the mapping is completed, in the EPC code, the domain name management has 4 binary digits left, and the object classification has 4 binary digits left; In the aviation equipment coding, the variety code has a total of 9 digits, of which the 1st and 2nd digits are fixed values ​​86 or 87 and are used to distinguish the coding agency. Therefore, the 1st and 2nd digits of the variety code can be represented in the EPC code with only 1 binary bit. The 1st and 2nd digits of the variety code are mapped to the domain name management office of the EPC code. At this time, there are 3 binary digits left in the domain name management office of the EPC code; the 3rd digit of the variety code has a specific meaning in the aviation equipment coding, including {0~9, M, S}, a total of 12 schemes, which are distinguished by 4-bit binary coding, so the 3rd digit is mapped to the object classification of the EPC code; the remaining 4-9 digits of the variety code are the variety serial code, which is composed of Arabic numerals 0~9 and uppercase letters except I and O. Each character of the 4-9 digits of the variety serial code is still represented by a 6-bit binary code. Therefore, the variety serial code requires a total of 36 binary bits, and the serial number part of the EPC code is 36 bits. The variety serial code is completely mapped to the serial number of the EPC code.

4. The EPC coding encryption method for aviation equipment based on improved Fesitel according to claim 2 is characterized in that: In S21, the first 8 bits of the version number of the EPC code are used as the scrambling code tweak, and the remaining 88 bits of data are equally divided into a left half left and a right half right, wherein the first 44 bits are left and the last 44 bits are right.

5. The aviation equipment EPC coding encryption method based on improved Fesitel according to claim 2 is characterized in that: In S22, the hash function is SHA-256, and the values ​​of ipad and opad are 0x36 and 0x5c respectively.

6. The aviation equipment EPC coding encryption method based on improved Fesitel according to claim 2 is characterized in that: In S23, each bit of the pseudo-random sequence s has a value of 0-9, and an 8-bit binary number is used to represent different values ​​of each bit. The first 6 bits of the pseudo-random sequence are intercepted and converted into binary to obtain a 48-bit binary number, and then the first 44 bits of the binary number are intercepted as the round key F.

7. The improved Fesitel-based EPC coding encryption method for aviation equipment according to claim 1 is characterized in that: It also includes the decryption process, specifically: using the same pseudo-random number generation mechanism and XOR operation as encryption, reversely executing the operations of the Feistel network, and gradually recovering the plaintext.

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