Data encryption processing method of passive RFID system
By generating random keys in passive RFID systems and cyclically encrypting and randomizing the data, the problem of insufficient information security in the existing technology is solved, efficient encryption and security improvement of data is achieved, and suitable for low-power Passive RF communication system.
Patent Information
- Application Number
- CN202411195774.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-29
- Publication Date
- 2024-12-17
AI Technical Summary
In RFID technology, existing passive systems are difficult to implement complex encryption processes due to low cost and power consumption, resulting in insufficient security of information and are easily copied or modified. A lightweight security algorithm and protocol are needed to improve data security and reliability.
By using basic symmetric encryption algorithms in passive RFID systems, random keys are generated and plaintext data are cyclically encrypted and randomized, ensuring that the same plaintext data outputs different ciphertexts, and using random keys and initialization vectors to enhance the data Security.
It improves the data security and reliability of the RFID communication process, ensures the security and effectiveness of data, is suitable for passive radio frequency communication systems, and does not require large power consumption.
Smart Images
Figure CN119155673A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of data encryption, and in particular to a data encryption processing method of a passive RFID system. Background Art
[0002] Radio frequency identification (RFID) is a method of remotely storing and retrieving data. RFID tags consist of an electronic chip and an antenna that detects radio signals transmitted by a reader. After receiving radio waves from an RFID reader device through the tag, it immediately sends digital information to the reader. Passive RFID systems use backscatter modulation. During the communication process, the reader emits a modulated signal that is received by the tag's antenna. An RF voltage is generated at the antenna input to power the chip, which returns information by changing its complex RF input impedance. The modulation of the backscattered signal is achieved by changing the impedance between two different states: impedance matching and mismatching.
[0003] In RFID technology, confidentiality and security of information are of vital importance. Insecure cards can be easily copied to retrieve or modify confidential information. RFID is widely used in the field due to its low cost and power consumption, but due to its low cost, it is not suitable for complex encryption processes and prefers lightweight security protocols and algorithms to ensure that costs are minimized while improving security. Summary of the invention
[0004] In order to solve the above technical problems, the present invention provides a data encryption processing method for a passive RFID system. Based on the basic symmetric encryption algorithm, the method improves the security and reliability of the data by supplementing the random key generation before encryption and the randomization processing of the encrypted data. It is a lightweight security algorithm and protocol that effectively improves the data security level of the RFID communication process.
[0005] The technical solution of the present invention is:
[0006] A data encryption processing method for a passive RFID system,
[0007] include
[0008] The first step is to generate a random key based on the product code of the electronic tag;
[0009] The second step is to process the plaintext data using cyclic encryption;
[0010] The third step is to randomize the encrypted data to generate the final encrypted data.
[0011] Furthermore,
[0012] By generating random keys and randomizing encrypted data, the same plaintext data input into the system will also output different ciphertexts. The decryption system can only parse the plaintext characters by outputting the serial number of fixed bytes in the ciphertext.
[0013] Going further,
[0014] Generating a random key involves:
[0015] The tag ID of the RFID electronic tag is read into the function func_A(). Once the data is read, the function generates a unique 16-byte random number for each TID. The random number is defined as a 4*4 matrix A, which is divided into a 4*4 byte matrix according to the byte order. Each cell has one byte of data, representing a word. The product code and the random number A are XORed to generate the first secret key K0.
[0016] Going further,
[0017] Data cyclic encryption includes the following steps:
[0018] (1) Generate secret key 1
[0019] The secret key A and the original plaintext matrix are XORed to generate the round key K0;
[0020] (2) Byte substitution
[0021] Based on the round key matrix, use the high-order digits of each byte of the hexadecimal number as rows and the low-order digits as columns, look up the corresponding numbers in the standard S-box table, and use this number to replace the original number to generate a new matrix B2;
[0022] (3) Row shift
[0023] Shift the rows of matrix B2. The shift standard is that the first row remains unchanged, the second row is circularly shifted to the left by 8 bits, the third row is circularly shifted to the left by 16 bits, and the fourth row is circularly shifted to the left by 24 bits, to obtain matrix B3.
[0024] (4) Column confusion
[0025] Operate the B3 matrix with the specified matrix C; each column of the B3 matrix is treated as a polynomial, then multiplied by the specified polynomial and then modulo x 4 +1, the calculation process of multiplying matrix B3 by matrix C to obtain matrix B4;
[0026] (5) Generate round key
[0027] Perform the XOR operation of step (1) on the matrix B4 and the new secret key K1 to generate a new matrix B5, and then execute steps (2)-(4) until the loop ends;
[0028] (6) Round Key Calculation
[0029] The generated round key K1 is looped through a new round, and steps (2)-(4) are executed. Then, a new round key K2 is generated. The loop is executed until the final round key K10 is generated. When step (3) is executed, the encryption is completed and the third step is entered for data randomization.
[0030] The new key K1 is obtained by key expansion of the original key. The algorithm for generating the round key K1 is as follows: each column of the state matrix A of the original key A is regarded as a word, namely w(0), w(1), w(2), w(3).
[0031]
[0032] Then the generation process of the words w(4), w(5), w(6), w(7) in each column of the round key K1 is: where the t function represents: first circularly shift left by 1 byte, then perform byte substitution (based on S-box), and then perform XOR with the round constant matrix C.
[0033]
[0034] Going further,
[0035] Data randomization
[0036] After the data is encrypted by the encryption algorithm, it is ciphertext, and then processed by the initialization vector, IV, to further enhance the randomness and security of the data. IV ensures that even if the same plaintext is encrypted multiple times with the same secret key, the ciphertext generated each time is different.
[0037] The invention ensures the security and validity of data. The solution does not require large power consumption and can be applied to passive radio frequency communication systems, and can encrypt long data by dividing plain text into blocks.
[0038] Since the encrypted ciphertext is randomized, that is, the same plaintext is encrypted multiple times using the same key, the ciphertext generated each time is different, which effectively improves the data security of wireless radio frequency communication. BRIEF DESCRIPTION OF THE DRAWINGS
[0039] Figure 1 It is a schematic diagram of the data encryption process;
[0040] Figure 2 It is a schematic diagram of the data cyclic encryption process;
[0041] Figure 3 It is a 12-level data randomization process. DETAILED DESCRIPTION
[0042] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.
[0043] The present invention proposes an encryption method for a passive RFID radio frequency identification system. The data processing process mainly includes three parts. The first step is to generate a random key according to the product code of the electronic tag; the second step is to process the plaintext data by cyclic encryption; the third step is to randomize the encrypted data to generate the final encrypted data. The whole process is shown in the attached figure. Figure 1 shown.
[0044] Data encryption process
[0045] 1. Generate a random key.
[0046] The tag identification (TID) of the RFID electronic tag is read into the function func_A(). Once the data is read, the function generates a unique 16-byte random number for each TID. The random number is defined as a 4*4 matrix A, which is divided into a 4*4 byte matrix according to the byte order. Each cell has one byte of data, representing a word. The product code and the random number A are XORed to generate the first secret key K0 of the system, as shown below:
[0047]
[0048] 2. Data cyclic encryption
[0049] (1) Generate secret key 1
[0050] The secret key A and the original plaintext matrix are XORed to generate the round key K0
[0051] (2) Byte substitution
[0052] Based on the round key matrix, use the high-order digits of each byte of the hexadecimal number as rows and the low-order digits as columns, find the corresponding number in the standard S-box table, and use this number to replace the original number (for example, if the original byte is 0x1a, use 1 as the row and a as the column, find the number from the S-box and replace the original byte position), and generate a new matrix B2
[0053] (3) Row shift
[0054] Shift the rows of matrix B2. The shift standard is that the first row remains unchanged, the second row is circularly shifted left by 8 bits, the third row is circularly shifted left by 16 bits, and the fourth row is circularly shifted left by 24 bits to obtain matrix B3.
[0055] (4) Column confusion
[0056] Perform a specific operation on the B3 matrix and the specified matrix C. Each column of the B3 matrix is treated as a polynomial, which is then multiplied by the specified polynomial and then modulo x. 4 +1, the calculation process of multiplying matrix B3 by matrix C, and obtaining matrix B4
[0057]
[0058] (5) Generate round key
[0059] Perform the XOR operation of the matrix B4 and the new secret key K1 in step (1) to generate a new matrix B5, and then perform steps (2)-(4) until the loop ends. The new key K1 is obtained by key expansion of the original key. The algorithm for generating the round key K1 is as follows:
[0060] Each column of the state matrix A of the original key A is regarded as a word, namely w(0), w(1), w(2), w(3).
[0061]
[0062] Then the generation process of the words w(4), w(5), w(6), w(7) in each column of the round key K1 is: where the t function represents: first circularly shift left by 1 byte, then perform byte substitution (based on S-box), and then perform XOR with the round constant matrix C.
[0063]
[0064] (6) Round Key Calculation
[0065] The generated round key K1 is looped through a new round, and steps (2)-(4) are executed. Then, a new round key K2 is generated. The loop is executed until the final round key K10 is generated. When step (3) is executed, the encryption is completed and the third step is entered for data randomization.
[0066] 3. Data Randomization
[0067] After the data is encrypted by the encryption algorithm, it is ciphertext, and then processed by the initialization vector (IV) to further enhance the randomness and security of the data. IV ensures that even if the same plaintext is encrypted multiple times with the same secret key, the ciphertext generated each time is different. Figure 3As shown in the figure, a 12-level random number generator will generate a new 12-bit random number each time. Step 2 The ciphertext after cyclic encryption and the 12-bit number generated by the random number generator are used for data randomization, and finally the encrypted ciphertext and the 12-bit number are output together. The 12-bit number is non-confidential and is used as the first key in the subsequent decryption process. The calculation algorithm is confidential. The process of data randomization is as follows:
[0068] Assume that the input data is X and the 12-bit random number is Y. Figure 3 As shown, the 12-digit number is from the highest digit to the lowest digit from left to right, and the calculation rules are:
[0069]
[0070] The description is that when I is in the range of [1-10], when biti is 1, x is shifted left by one bit; when biti is 0, x is added by 1 and then shifted left by (10-i) bits; when i is in the range of [11-12], x is The result is XORed and then negated to finally calculate the value of X.
[0071] Based on the cyclic encryption algorithm, the present invention increases the generation of random keys and the random processing of encrypted data, so that the same plaintext data input system will also output different ciphertexts. The decryption system can effectively parse the plaintext characters by outputting the serial number of fixed bytes in the ciphertext, thereby ensuring the security and effectiveness of the data. The scheme does not require high power consumption and can be applied to passive radio frequency communication systems. Long data can be encrypted by dividing the plaintext into blocks.
[0072] The above description is only a preferred embodiment of the present invention, which is only used to illustrate the technical solution of the present invention, and is not used to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.
Claims
1. A data encryption processing method for a passive RFID system, characterized in that: include The first step is to generate a random key based on the product code of the electronic tag; The second step is to process the plaintext data using cyclic encryption; The third step is to randomize the encrypted data to generate the final encrypted data.
2. The method according to claim 1, characterized in that By generating random keys and randomizing encrypted data, the same plaintext data input into the system will also output different ciphertexts.
3. The method according to claim 2, characterized in that The decryption system can parse the plaintext characters by outputting the serial number of fixed bytes in the ciphertext.
4. The method according to claim 1, 2 or 3, characterized in that: Generating a random key involves: The tag identification of the RFID electronic tag is read into the function func_A(). Once the data is read, the function generates a unique 16-byte random number for each TID. The random number is defined as a 4*4 matrix A, which is divided into a 4*4 byte matrix according to the byte order. Each cell has one byte of data, representing a word.
5. The method according to claim 4, characterized in that The product code and random number A are XORed to generate the first secret key K0.
6. The method according to claim 5, characterized in that Data cyclic encryption includes the following steps: (1) Generate secret key 1 The secret key A and the original plaintext matrix are XORed to generate the round key K0; (2) Byte substitution Based on the round key matrix, use the high-order digits of each byte of the hexadecimal number as rows and the low-order digits as columns, look up the corresponding numbers in the standard S-box table, and use this number to replace the original number to generate a new matrix B2; (3) Row shift Shift the rows of matrix B2. The shift standard is that the first row remains unchanged, the second row is circularly shifted to the left by 8 bits, the third row is circularly shifted to the left by 16 bits, and the fourth row is circularly shifted to the left by 24 bits, to obtain matrix B3. (4) Column confusion Operate the B3 matrix with the specified matrix C; each column of the B3 matrix is treated as a polynomial, then multiplied by the specified polynomial and then modulo x 4 +1, the calculation process of multiplying matrix B3 by matrix C to obtain matrix B4; (5) Generate round key Perform the XOR operation of step (1) on the matrix B4 and the new secret key K1 to generate a new matrix B5, and then execute steps (2)-(4) until the loop ends; (6) Round Key Calculation The generated round key K1 is looped through a new round, and steps (2)-(4) are executed. Then, a new round key K2 is generated. The loop is executed until the final round key K10 is generated. When step (3) is executed, the encryption is completed and the third step, data randomization, is entered.
7. The method according to claim 6, characterized in that The new key K1 is obtained by key expansion of the original key. The algorithm for generating the round key K1 is as follows: each column of the state matrix A of the original key A is regarded as a word, namely w(0), w(1), w(2), w(3). Then the generation process of the words w(4), w(5), w(6), w(7) in each column of the round key K1 is: where the t function represents: first cyclically shift left by 1 byte, then perform byte substitution (based on S-box), and then perform XOR with the round constant matrix C; 8. The method according to claim 6, characterized in that Data randomization After the data passes through the encryption algorithm, it becomes ciphertext, which is then processed by the initialization vector, IV, to further enhance the randomness and security of the data; IV ensures that even if the same plaintext is encrypted several times with the same secret key, the ciphertext generated each time is different.