CN110868717A - Method for improving wireless communication security based on DES encryption algorithm - Google Patents
Method for improving wireless communication security based on DES encryption algorithm Download PDFInfo
- Publication number
- CN110868717A CN110868717A CN201911228982.9A CN201911228982A CN110868717A CN 110868717 A CN110868717 A CN 110868717A CN 201911228982 A CN201911228982 A CN 201911228982A CN 110868717 A CN110868717 A CN 110868717A
- Authority
- CN
- China
- Prior art keywords
- bit
- key
- data
- bits
- encryption algorithm
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000006854 communication Effects 0.000 title claims abstract description 27
- 238000004891 communication Methods 0.000 title claims abstract description 25
- 238000000034 method Methods 0.000 title claims abstract description 21
- 238000006467 substitution reaction Methods 0.000 claims description 14
- 230000009466 transformation Effects 0.000 claims description 5
- 230000008859 change Effects 0.000 claims description 4
- 238000013507 mapping Methods 0.000 claims description 4
- 125000004122 cyclic group Chemical group 0.000 claims description 3
- 230000008569 process Effects 0.000 abstract description 3
- 238000013478 data encryption standard Methods 0.000 description 19
- 101100014709 Drosophila melanogaster wisp gene Proteins 0.000 description 5
- 238000005259 measurement Methods 0.000 description 3
- 230000001133 acceleration Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 230000008520 organization Effects 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000036760 body temperature Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000005672 electromagnetic field Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000003306 harvesting Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000000844 transformation Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W12/00—Security arrangements; Authentication; Protecting privacy or anonymity
- H04W12/02—Protecting privacy or anonymity, e.g. protecting personally identifiable information [PII]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
- H04L9/06—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols the encryption apparatus using shift registers or memories for block-wise or stream coding, e.g. DES systems or RC4; Hash functions; Pseudorandom sequence generators
- H04L9/0618—Block ciphers, i.e. encrypting groups of characters of a plain text message using fixed encryption transformation
- H04L9/0625—Block ciphers, i.e. encrypting groups of characters of a plain text message using fixed encryption transformation with splitting of the data block into left and right halves, e.g. Feistel based algorithms, DES, FEAL, IDEA or KASUMI
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W12/00—Security arrangements; Authentication; Protecting privacy or anonymity
- H04W12/04—Key management, e.g. using generic bootstrapping architecture [GBA]
Landscapes
- Engineering & Computer Science (AREA)
- Computer Security & Cryptography (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
The invention relates to a method for improving wireless communication security based on a DES encryption algorithm, which belongs to the technical field of radio frequency communication systems, and adopts the technical scheme that the DES encryption algorithm is optimized by establishing a plaintext block, initial replacement, expanded replacement, S box replacement and P box replacement, and then the optimized DES encryption algorithm is loaded on a radio frequency identification tag; aiming at the problem of privacy leakage possibly caused by adopting a wireless communication mode in the process of carrying out radio frequency communication between the tag and the reader, the invention can effectively solve the problem of poor safety performance possibly encountered in the process of the radio communication by adopting a radio frequency communication protocol based on a DES encryption algorithm in the radio communication.
Description
Technical Field
The invention belongs to the technical field of radio frequency communication systems, relates to the safety performance of a radio frequency communication system, and particularly relates to a method for improving the safety of wireless communication based on a DES encryption algorithm.
Background
Under the large background of rapid development of the internet of things, Radio Frequency identification technology (RFID) is a trend of future development, wherein a Radio Frequency identification tag with a microcontroller and a sensor is a mainstream direction of current research. By standardizing the RFID protocol with off-the-shelf commercial RFID readers, the tag can harvest energy for its operation from the electromagnetic field provided by the reader. The tag does not require maintenance because it does not require an onboard power supply and does not wear the interface or cables due to mechanical stress. The additional microcontroller allows the measurement data to be processed, stored or filtered at the tag end before being transmitted to the reader. The radio frequency channel may be out of view while supporting continuous access by the reader to multiple tags and may communicate over a range of more than one meter.
However, the tag and the reader communicate with each other in a wireless manner. Eavesdropping the communication between the tag and the reader is much simpler than eavesdropping communication based on a wired approach. Depending on the application scenario, a competitor or potential attacker may be interested in the sensor measurement data of the tag. Especially in the case of tags measuring data related to personal privacy (e.g. location information, body temperature), serious end-user privacy leakage problems may arise.
The DES encryption algorithm has extremely high security, and no more effective method is found except that the DES encryption algorithm is attacked by an exhaustive search method. If a computer is running at a speed of one million keys per second, it takes nearly 2285 years to search for all keys.
Disclosure of Invention
The invention overcomes the defects of the prior art, provides a method for improving the security of wireless communication based on a DES encryption algorithm, and solves the problem of poor security possibly encountered in the prior wireless communication process by utilizing a radio frequency communication protocol improvement scheme based on the DES encryption algorithm.
In order to achieve the above object, the present invention is achieved by the following technical solutions.
1. A method for improving wireless communication security based on DES encryption algorithm is characterized by comprising the following steps:
1) optimizing DES encryption algorithm
a. Establishing a plaintext group: setting a mode as an encryption mode, and grouping the plaintext according to 64 bits to form a plaintext group; the DES encryption algorithm has three entry parameters, which are: the key is a key used for encryption and decryption, the data is data for encryption and decryption, and the mode is the working mode of the key.
b. Initial replacement: generating 16 rounds of 48-bit sub-keys by using 64 bits of the 64-bit key, and dividing the 56-bit key into two blocks of C0 and D0 with 28 bits; generating C1 and D1 after transformation by performing a round-robin left shift change on C0 and D0, combining C1 and D1, and generating a sub-key K1 by selecting a substitution table; the cyclic left shift transformation is repeated to obtain K16 and R16, and finally R16 and L16 are combined.
c. Expanding and replacing: r0 carries out exclusive OR operation with the sub key after carrying out expansion permutation; the right half Rn of the data extends from 32 bits to 48 bits.
d. S box replacement: and after the Rn expansion permutation, performing S-box substitution operation by using the sub key Kn as an input block to change 48-bit data into 32-bit data.
e. P box replacement: mapping each bit input bit to output bit, and performing P-box permutation to obtain the result different from the left half of the first 64-bit packet, and then exchanging the two parts to start the next iteration.
2) Loading the optimized DES encryption algorithm on the radio frequency identification label
The encryption of the SENSOR data is performed directly within the STATE READ SENSOR; with encryption enabled, the STATE READ SENSOR distinguishes whether new data must be sampled from the SENSOR.
Further, the key is used for encrypting the data, and when the mode is the decryption mode, the key is used for decrypting the data.
Further, the initial permutation is circularly moved left 16 times; wherein the first time, the second time, the ninth time and the sixteenth time are circularly shifted left by one bit, and the other times are shifted left by two bits.
Further, C1 and D1 undergo round-robin left-shift transformations to generate C2 and D2, which are then combined with C2 and D2 to generate 48-bit keys K2 and R2 by selectively permuting PC-2.
Further, the extended permutation generates data with the same length as the key for exclusive-or operation, R0 is 32 bits, and the sub-key is 48 bits.
Further, R0 is first subjected to the expanding permutation and then subjected to the exclusive or operation with the sub-key.
Further, the S-box substitution operation is performed by 8 different S-boxes, each S-box having 6-bit input and 4-bit output, and the 48-bit input block is divided into 8 6-bit groups, each group corresponding to one S-box substitution operation.
Compared with the prior art, the invention has the beneficial effects that.
The invention provides a radio frequency communication protocol improvement scheme based on a DES encryption algorithm aiming at the problem of privacy leakage possibly caused by adopting a wireless communication mode in the radio frequency communication process of a tag and a reader.
Drawings
Fig. 1 shows a tag ID response structure under the EPC C1G2 protocol according to the present invention.
Fig. 2 shows the organization of the state and key bytes in the AES algorithm of the present invention.
Fig. 3 is a flow chart of the DES encryption algorithm of the present invention.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail with reference to the embodiments and the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. The technical solution of the present invention is described in detail below with reference to the embodiments and the drawings, but the scope of protection is not limited thereto.
A method for improving wireless communication security based on DES encryption algorithm comprises the following specific processes:
1. sensor data transmission mode of label
The tag adopted by the invention is WISP, and supports two operation modes when transmitting the sensor data to the reader end. The first method is to transmit sensor data as a response to a read command issued by a reader, and the second method is to store the data in the ID of a tag and transmit the data. Since the second mode can save communication overhead and has better communication range and performance effect, the invention adopts a mode of storing sensor data in the ID of the tag for transmission. FIG. 1 shows the tag ID reply format under the standard EPC Class-1 Generation-2 protocol. It can be seen that the reply of the tag consists of a preamble of 16 bits, an ID field of 96 bits and a cyclic redundancy check code of 16 bits. In which the 96-bit ID field is divided into four logical units. The first field, the 8-bit tag type, indicates the type of sensor that generated the data, so that it can be known what data was transmitted. According to different 8-bit label types, six conditions of static ID, no sensor, light acceleration sensor, standard acceleration sensor, built-in temperature sensor and external temperature sensor can be represented respectively. The next eight bytes are used to transmit the actual sensor data. Depending on the type of sensor, 2 to 6 bytes of the data field are used for storing the encoded measurement data, and the remaining two bytes are used as a running counter. The data field is followed by an 8-bit WISP hardware version number and a 16-bit WISP sequence number.
2. DES (data Encryption Standard) Encryption algorithm
The DES encryption algorithm has three entry parameters: key, data, mode. The key is a key used for encryption and decryption, the data is data for encryption and decryption, and the mode is the working mode of the key. When the mode is encryption mode, the plaintext is grouped according to 64 bits to form a plaintext group, which is also called state. The key is used to encrypt data, and when the mode is a decryption mode, the key is used to decrypt data. In practice, the key only uses 56 bits out of 64 bits, which has higher security. The organization of the states and keys is shown in fig. 2.
The DES encryption flow is shown in fig. 3. The sixteen rounds of the same operation are divided into 4 stages of sub-key generation, expansion replacement, S-box replacement and P-box replacement, and the 4 stages enable input data to be fully encrypted. The DES algorithm generates 16 rounds of 48-bit sub-keys from a 64-bit key. In each iteration, a different sub-key is used. Dividing the 56-bit key with the parity bits omitted into two blocks, C0(28 bits) and D0(28 bits), according to the selective permutation table 1; c0 and D0 are subjected to cycle left shift change (note: the number of bits of left shift of each cycle is determined by the number of rounds), C1 and D1 are generated after conversion, then C1 and D1 are combined, and a sub-key K1(48 bits) is generated by selecting and replacing table 2; c1 and D1 are circularly left-shifted and transformed at the second time to generate C2 and D2, and then C2 and D2 are combined to generate a key K2(48 bits) by selecting the replacement PC-2; by analogy, K16 (bit 48) is obtained. But the left and right parts of the last round are not swapped, but R16 and L16 are directly merged together as the input block of the inverse permutation. The number of bits of the left shift of the loop is 16 times of the left shift of the loop, wherein the first time, the second time, the ninth time and the sixteenth time are the left shift of the loop by one bit, and the others are the left shift by two bits.
The permutation is extended and the right half Rn of the data is extended from 32 bits to 48 bits. The extended permutation changes the order of the bits, repeating some bits. The extended permutation may generate data with the same length as the key for exclusive-or operation, where R0 is 32 bits and the sub-key is 48 bits, so R0 performs the extended permutation and then performs the exclusive-or operation with the sub-key; extended permutations may also provide longer results, enabling compression when S-box substitution operations.
And S-box substitution, wherein the result of exclusive OR of the result after the Rn expansion permutation and the sub key Kn is used as an input block to perform S-box substitution operation, and 48-bit data is changed into 32-bit data. The substitution operation is performed by 8 different substitution boxes (S-boxes). Each S-box has 6 bits input and 4 bits output. The 48-bit input block is divided into 8 6-bit packets, each corresponding to one S-box substitution operation.
P-box permutation, mapping each bit input bit to an output bit. Neither bit can be mapped twice nor ignored. The result of the P-box permutation is different from the left half of the initial 64-bit grouping or, then, the left and right parts are swapped, and the next iteration is started.
3. Workflow for implementing encryption on WISP
And the optimized DES assembly program is used at the WISP tag end for implementation. To avoid abnormal changes in the firmware and STATE flow, the encryption of the SENSOR data is performed directly within the STATE _ READ _ SENSOR. Typically, this state collects sensor data by invoking a subroutine that activates the sensor device. If encryption is enabled, the STATE READ SENSOR can distinguish whether new data must be sampled from the SENSOR. When a sensor needs to be sampled, the measured sensor data is immediately encrypted. The ciphertext is then written to the ID reply buffer.
While the invention has been described in further detail with reference to specific preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (7)
1. A method for improving wireless communication security based on DES encryption algorithm is characterized by comprising the following steps:
1) optimizing DES encryption algorithm
a. Establishing a plaintext group: setting a mode as an encryption mode, and grouping the plaintext according to 64 bits to form a plaintext group; the DES encryption algorithm has three entry parameters, which are: the key is a key used for encryption and decryption, the data is data for encryption and decryption, and the mode is the working mode of the key;
b. initial replacement: generating 16 rounds of 48-bit sub-keys by using 64 bits of the 64-bit key, and dividing the 56-bit key into two blocks of C0 and D0 with 28 bits; generating C1 and D1 after transformation by performing a round-robin left shift change on C0 and D0, combining C1 and D1, and generating a sub-key K1 by selecting a substitution table; repeating the cyclic left shift transformation to obtain K16 and R16, and finally combining R16 and L16;
c. expanding and replacing: r0 carries out exclusive OR operation with the sub key after carrying out expansion permutation; the right half Rn of the data extends from 32 bits to 48 bits;
d. s box replacement: after the Rn expansion and permutation, the Rn and the sub key Kn are used as input blocks to carry out S box substitution operation, and 48-bit data are changed into 32-bit data;
e. p box replacement: mapping each bit input bit to an output bit, performing P-box permutation on the result of the mapping to be different from the left half of the first 64-bit grouping, then exchanging the left part and the right part, and starting the next iteration;
2) loading the optimized DES encryption algorithm on the radio frequency identification label
The encryption of the SENSOR data is performed directly within the STATE READ SENSOR; with encryption enabled, the STATE READ SENSOR distinguishes whether new data must be sampled from the SENSOR.
2. The DES encryption algorithm-based method for improving security of wireless communication according to claim 1,
the key is used for encrypting data, and when the mode is a decryption mode, the key is used for decrypting the data.
3. The method for improving security of wireless communication based on DES encryption algorithm of claim 1, wherein the initial permutation is circularly left shifted 16 times; wherein the first time, the second time, the ninth time and the sixteenth time are circularly shifted left by one bit, and the other times are shifted left by two bits.
4. The method of claim 1, wherein C1 and D1 are circularly left-shifted to generate C2 and D2, and then C2 and D2 are combined to generate 48-bit keys K2 and R2 by selecting the replacement PC-2.
5. The method of claim 1, wherein the extended permutation generates data with the same length as the key for exclusive-or operation, R0 is 32 bits, and the sub-key is 48 bits.
6. The method of claim 1, wherein R0 is first permuted by expansion and then XOR' ed with the sub-key.
7. The method of claim 1, wherein the S-box substitution operation is performed by 8 different S-boxes, each S-box having 6-bit input and 4-bit output, and the 48-bit input block is divided into 8 6-bit groups, each group corresponding to one S-box substitution operation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911228982.9A CN110868717A (en) | 2019-12-04 | 2019-12-04 | Method for improving wireless communication security based on DES encryption algorithm |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911228982.9A CN110868717A (en) | 2019-12-04 | 2019-12-04 | Method for improving wireless communication security based on DES encryption algorithm |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110868717A true CN110868717A (en) | 2020-03-06 |
Family
ID=69658495
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911228982.9A Pending CN110868717A (en) | 2019-12-04 | 2019-12-04 | Method for improving wireless communication security based on DES encryption algorithm |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110868717A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113468587A (en) * | 2021-09-02 | 2021-10-01 | 深圳市通易信科技开发有限公司 | User data management method and system based on big data and readable storage medium |
| CN113660620A (en) * | 2021-10-20 | 2021-11-16 | 北京卓建智菡科技有限公司 | Data anti-counterfeiting encryption method and device, computer equipment and storage medium |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102129591A (en) * | 2011-03-04 | 2011-07-20 | 电子科技大学 | Active radio frequency identification (RFID) sensing tag with low power consumption and control method thereof |
| CN104899620A (en) * | 2015-05-12 | 2015-09-09 | 广州中大微电子有限公司 | RFID reading and writing device with safe processing function |
| CN108134664A (en) * | 2016-12-01 | 2018-06-08 | 钦州市晶通科技有限公司 | A kind of implementation method of data encryption |
| CN108270545A (en) * | 2016-12-30 | 2018-07-10 | 广东精点数据科技股份有限公司 | A kind of improved DES data encryption algorithm based on mobile Internet |
| CN108737070A (en) * | 2018-04-24 | 2018-11-02 | 国网山东省电力公司日照供电公司 | Based on the power grid data transmission method of mobile terminal for improving des encryption algorithm |
| CN108763982A (en) * | 2018-05-30 | 2018-11-06 | 浙江矽微智能科技有限公司 | A kind of des encryption suitable for RFID reader decrypts device |
-
2019
- 2019-12-04 CN CN201911228982.9A patent/CN110868717A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102129591A (en) * | 2011-03-04 | 2011-07-20 | 电子科技大学 | Active radio frequency identification (RFID) sensing tag with low power consumption and control method thereof |
| CN104899620A (en) * | 2015-05-12 | 2015-09-09 | 广州中大微电子有限公司 | RFID reading and writing device with safe processing function |
| CN108134664A (en) * | 2016-12-01 | 2018-06-08 | 钦州市晶通科技有限公司 | A kind of implementation method of data encryption |
| CN108270545A (en) * | 2016-12-30 | 2018-07-10 | 广东精点数据科技股份有限公司 | A kind of improved DES data encryption algorithm based on mobile Internet |
| CN108737070A (en) * | 2018-04-24 | 2018-11-02 | 国网山东省电力公司日照供电公司 | Based on the power grid data transmission method of mobile terminal for improving des encryption algorithm |
| CN108763982A (en) * | 2018-05-30 | 2018-11-06 | 浙江矽微智能科技有限公司 | A kind of des encryption suitable for RFID reader decrypts device |
Non-Patent Citations (2)
| Title |
|---|
| 徐鹏等: "抗差分功耗攻击的DES算法研究", 《计算机仿真》 * |
| 蒋冠宇;蒋泰;邓家明;张余明;: "一种超高频RFID读写器的设计与实现" * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113468587A (en) * | 2021-09-02 | 2021-10-01 | 深圳市通易信科技开发有限公司 | User data management method and system based on big data and readable storage medium |
| CN113660620A (en) * | 2021-10-20 | 2021-11-16 | 北京卓建智菡科技有限公司 | Data anti-counterfeiting encryption method and device, computer equipment and storage medium |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Engels et al. | The Hummingbird-2 lightweight authenticated encryption algorithm | |
| US7688974B2 (en) | Rijndael block cipher apparatus and encryption/decryption method thereof | |
| US8369522B2 (en) | Encryption processing apparatus, encryption method, and computer program | |
| US8428251B2 (en) | System and method for stream/block cipher with internal random states | |
| EP3014800B1 (en) | Method and apparatus to encrypt plaintext data | |
| JP5682527B2 (en) | Cryptographic processing apparatus, cryptographic processing method, and program | |
| EP1833190B1 (en) | Table splitting for cryptographic processes | |
| US8489897B2 (en) | Method and circuitry for detecting a fault attack | |
| US20150019878A1 (en) | Apparatus and Method for Memory Address Encryption | |
| US8619985B2 (en) | Table splitting for cryptographic processes | |
| KR20130041353A (en) | Apparatus and method for block cipher process for insecure environments | |
| Zhang et al. | LAC: A lightweight authenticated encryption cipher | |
| US20160119121A1 (en) | Encryption/decryption apparatus and encryption/decryption method thereof | |
| CN110868717A (en) | Method for improving wireless communication security based on DES encryption algorithm | |
| CN116722968A (en) | Lightweight AES-128 dynamic encryption method based on UWB | |
| CN104219045A (en) | RC4 (Rivest cipher 4) stream cipher generator | |
| KR100456599B1 (en) | Cryptographic apparatus with parallel des structure | |
| CN101882991B (en) | Communication data stream encryption method based on block cipher | |
| CN114826558B (en) | Method and system for quickly encrypting mass data | |
| US20120321079A1 (en) | System and method for generating round keys | |
| KR101135058B1 (en) | Encryption method and encryption device using differential fault analysis in round key generation of Data Encryption Standard | |
| CN108763982B (en) | DES encryption and decryption device suitable for RFID reader | |
| EP1629626B1 (en) | Method and apparatus for a low memory hardware implementation of the key expansion function | |
| US10678709B2 (en) | Apparatus and method for memory address encryption | |
| CN105553644A (en) | 32-bit-packet length lightweight encryption and decryption method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200306 |