CN113872748B - Safe quantum network coding method based on quantum homomorphic encryption - Google Patents
Safe quantum network coding method based on quantum homomorphic encryption Download PDFInfo
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- CN113872748B CN113872748B CN202111133347.XA CN202111133347A CN113872748B CN 113872748 B CN113872748 B CN 113872748B CN 202111133347 A CN202111133347 A CN 202111133347A CN 113872748 B CN113872748 B CN 113872748B
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- 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
- H04L9/008—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols involving homomorphic encryption
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- 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
- H04L9/08—Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords
- H04L9/0816—Key establishment, i.e. cryptographic processes or cryptographic protocols whereby a shared secret becomes available to two or more parties, for subsequent use
- H04L9/0852—Quantum cryptography
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S40/00—Systems for electrical power generation, transmission, distribution or end-user application management characterised by the use of communication or information technologies, or communication or information technology specific aspects supporting them
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Abstract
The invention belongs to the field of quantum communication network technology and quantum cryptography, and particularly relates to a safe quantum network coding method based on quantum homomorphic encryption. According to the method, quantum homomorphic encryption is applied to quantum network coding, and the quantum state of the measurement result of the sender is encrypted, so that the intermediate node in the butterfly network cannot obtain the information of the quantum state to be transmitted of the sender, and safe quantum network coding is realized.
Description
Technical Field
The invention relates to a safe quantum network coding method based on quantum homomorphic encryption, belonging to the fields of quantum communication network technology and quantum cryptography.
Background
In recent decades, the rapid development of quantum information has not been separated from the study of quantum cryptography by researchers. In particular, quantum invisible transmission technology and quantum key distribution technology are sequentially proposed, the former realizes remote transmission of quantum states by utilizing characteristics of quantum entangled states, and the latter completes perfect and safe quantum key distribution by utilizing theorem that quantum states cannot be precisely cloned, so that quantum communication network technology is also applied.
In 2006, hayashi et al propose a quantum network coding scheme based on a butterfly network model for the first time, and cross transmission of quantum states on a butterfly network is realized by a quantum universal cloning method. Since quantum universal cloning methods are not exact clones, this approach does not allow perfect transmission with fidelity of 1. In 2007, hayashi proposed a quantum network coding scheme based on quantum invisible transmission states, and perfect cross transmission of quantum states on a butterfly network was realized through entangled states shared in advance by two senders. However, if the first intermediate node in the butterfly network is dishonest, the node may obtain the quantum state from the channel and recover the information of the quantum states to be transmitted of the two senders, resulting in the security of the scheme being insufficient. From the shortcomings of this scheme, it can be found that this belongs to the security problem that the sender gives the private data to the intermediate node for encoding, and relates to both the protection of the content by the private data and the delegation of the calculation content.
The explosion of quantum information science brings about many new findings for information processing applications, wherein quantum homomorphic encryption is a considerable entrusted computing technology, which can not only ensure the privacy of ciphertext after encrypting plaintext by a client in evaluation operation performed by a server, but also make the result after performing decryption operation by the client equal to the result of directly acting on plaintext by the evaluation operation. Therefore, the invention provides a quantum network coding method based on quantum homomorphic encryption, which encrypts the quantum state of the measurement result of the sender, so that the intermediate node in the butterfly network cannot decrypt and obtain the information of the quantum state to be transmitted of the sender, but the intermediate node is not influenced to finish the function of network coding, and the safe cross transmission of the quantum state in the butterfly network is realized.
Disclosure of Invention
According to the problem of insufficient safety in the prior art, the invention provides a safe quantum network coding method based on quantum homomorphic encryption, which can improve the safety of the transmission of a quantum state to be transmitted in a butterfly network. The method mainly comprises the following steps:
step one: sender A through two rounds of quantum invisible state transmission processes 1 And A 2 Transferring the information of the quantum states to be transmitted to the opposite side, wherein A is 1 And A 2 The entangled quantum state in the hand will become the quantum state to be recovered, and A 1 And A 2 A set of measurements of classical bit sequences were also obtained, respectively.
Step two: sender a based on the respective measurements 1 And A 2 And respectively executing corresponding unitary operation on the quantum states to be recovered in the hands to obtain encrypted quantum states to be transmitted.
Step three: sender A 1 And A 2 Respectively quantizing classical bit sequences of the respective measurement results to obtain measurement quantum states; in addition, A 2 The measured quantum states in the adversary are encrypted with an encryption key,and obtaining the encrypted measurement quantum state.
Step four: sender A 1 Measured quantum state of (c) and sender a 2 Is transmitted to the intermediate node C through the channel 1 And A is 2 Transmitting the encryption key to A through quantum key distribution technology 1 The method comprises the steps of carrying out a first treatment on the surface of the In addition to A 1 And A 2 Respectively transmitting the respective encrypted quantum states to be transmitted and the encryption key to the receiver B 2 And B 1 。
Step five: intermediate node C 1 Performing controlled unitary operation on the two groups of measurement quantum states, and transmitting the obtained new group of measurement quantum states to the intermediate node C 2 。
Step six: intermediate node C 2 Copying the new measured quantum states and respectively transmitting to the receiver B 1 And B 2 。
Step seven: according to intermediate node C 2 New measured quantum state and sender a 2 Is the encryption key of receiver B 1 Performing decryption operation on the new measurement quantum state to obtain a decrypted measurement quantum state; based on the measured quantum state information, B 1 For the A 2 Decrypting the encrypted quantum state to be transmitted, and recovering to obtain A 1 To be transmitted.
Step eight: similarly, receiver B based on the received new measured quantum state and encryption key 2 Performing decryption operation on the new measurement quantum state to obtain a decrypted measurement quantum state; further, from the decrypted information of the measured quantum state, B 2 Pair A 1 The encrypted quantum state to be transmitted of (2) is also subjected to corresponding decryption operation to recover to obtain A 2 To be transmitted.
The invention has the beneficial effects that:
the cross transmission of quantum states in the butterfly network is realized through entanglement resources, and the method is a quantum network coding method of a more important class. However, such methods generally default that intermediate nodes in the butterfly network are honest and reliable, and do not attempt to obtain quantum state information to be transmitted of a sender. According to the method, quantum homomorphic encryption is applied to quantum network coding, whether the intermediate node is honest and reliable or not, the measured quantum state information of a sender is encrypted, the measured quantum state information is not exposed to the intermediate node, the safety and the integrity of data in the coding process are ensured, meanwhile, the intermediate node can complete the coding task, and the safe cross transmission of the quantum state in a butterfly network is realized.
Drawings
FIG. 1 is a flow chart of a secure quantum network encoding method employing quantum homomorphic encryption in accordance with the present invention;
fig. 2 is a butterfly network diagram of the secure quantum network encoding method of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions in the embodiments of the present invention will be fully and clearly described below with reference to the accompanying drawings. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention.
The invention provides a safe quantum network coding method based on quantum homomorphic encryption, which mainly comprises the following steps:
step one: sender A 1 And A 2 Respectively are to be transmitted quantum statesAndwherein |α| 2 +|β| 2 ＝1，|γ| 2 +|λ| 2 ＝1。A 1 And A 2 Two pairs of Bell states are shared:
wherein sender A 1 Possessing quantum state a 1,1 And a 1,2 Sender A 2 Possessing quantum state a 2,1 And a 2,2 。
In the first round of quantum invisible state transmission process, the quantum state to be operated isAnd->Sender A 1 In quantum state a 1 To control bit and quantum state a 1,1 CNOT operation is performed on the target bit, and then quantum state a is performed again 1 Operate H, i.e
Wherein the method comprises the steps of
Then sender A 1 Measuring the quantum state a he owns 1 And a 1,1 One of four possible results 00, 01, 10 and 11 is obtained, the measurement of the classical bit sequence being noted as m 1 m 2 (m 1 ,m 2 E {0,1 }). Sender A at this time 2 Owned entangled quantum state a 2,1 Becomes as follows
Similarly, in the second round of quantum invisible transmission, the quantum state being operated isAnd->Sender A 2 In quantum state a 2 To control bit and quantum state a 2,2 CNOT operation is performed on the target bit, and then quantum state a is performed again 2 Operate H, i.e
Thereafter, sender A 2 Measuring the quantum state a he owns 2 And a 2,2 One of four possible outcomes 00, 01, 10 and 11 was also obtained and the classical bit sequence was noted as n 1 n 2 (n 1 ,n 2 E {0,1 }). Sender A at this time 1 Owned entangled quantum state a 1,2 Becomes as follows
Step two: according to sender A 1 Measurement result m of (2) 1 m 2 And sender A 2 Is measured by the measurement result n of (2) 1 n 2 ，A 1 And A 2 Respectively to the quantum states in the respective handsAnd->Performing corresponding unitary operations, i.e.
Thus, through this step, A 1 And A 2 Respectively obtain the encrypted quantum state to be transmittedAnd->
Step three: sender A 1 And A 2 Respectively quantizing classical bit sequences of the respective measurement results to obtain measurement quantum state |m 1 >|m 2 >And |n 1 >|n 2 >. In order to ensure the safety of the whole quantum network coding, the invention adopts the encryption keys e, f, g and h (e, f, g, h E {0,1 }) generated randomly to pair A based on the idea of quantum homomorphic encryption 2 Is (are) measured in quantum states |n 1 >|n 2 >Encrypting to obtain an encrypted measurement quantum state X e Z f |n 1 >X g Z h |n 2 >. In order not to increase the complexity of the network coding, the invention does not apply to A 1 Is of the quantum state |m 1 >|m 2 >Additional encryption is performed.
Step four: sender A 1 And A 2 The respective measured quantum states |m 1 >|m 2 >And X e Z f |n 1 >·X g Z h |n 2 >Transmitted to intermediate node C via a channel 1 And A is 2 Transmitting encryption keys e, f, g and h to A through quantum key distribution technology 1 . In addition, A 1 To encrypt the quantum state to be transmittedAnd an encryption key e, f, g, h to the receiver B 2 And A 2 The quantum state to be transmitted is encrypted>And an encryption key e, f, g, h to the receiver B 1 。
Step five: intermediate node C 1 Performing CNOT operation twice on the two groups of received measurement quantum states, specifically C 1 At |m 1 >To control the position, X e Z f |n 1 >Doing a first CNOT operation for target bit 2 >To control the position, X g Z h |n 2 >Doing a second CNOT operation for the target bit, i.e
Wherein the method comprises the steps ofRepresenting the exclusive or operator. C (C) 1 Will->And->As a new set of measured quantum states and sent to intermediate node C 2 。
Step six: intermediate node C 2 Preparation of two auxiliary Quantum states |0>And replicates the new measured quantum state. The specific operation is thatAnd->Respectively as control bits, respectively to target bits |0>Doing CNOT operation, i.e
C 2 Will beAnd->As a set of measured quanta to be sent to receiver B 1 Will leave->And->As another set of measured quanta to be sent to receiver B 2 。
It can be found that the two sets of measurement quanta are just unitary operators Z f Or Z is h This also simply results in the copied measured quantum state possibly lacking a global phase factor of-1 and does not affect the decryption operations in step seven, step eight.
Step seven: first, according to the encryption key e, f, g, h, the receiver B 1 Received measurement quantum statePerforming decryption operation to obtain quantum state->Next, B 1 For quantum state->Taking measurements to obtain classical bit sequence +.>Finally, based on classical bit information, B 1 For the A 2 Is to be transmitted in the form of a quantum state>Decrypting, i.e.
Recovering to obtain A 1 To be transmitted in the quantum state alpha|0>+β|1>。
Step eight: receiver B 2 Obtaining A 2 B in the process and step seven of quantum state information to be transmitted 1 Is consistent with the operation of, in particular B 2 Measuring quantum state according to information pair of encryption keyPerforming decryption operation to obtain quantum state->B 2 And then->Making measurements to obtain classical bit sequencesB 2 Finally, according to classical bit information, the bit information is derived from A 1 Is to be transmitted in the form of a quantum state>Decrypting, i.e.
Recovering to obtain A 2 To be transmitted in the quantum state gamma|0>+λ|1>。
Through the eight steps, the invention can realize safe quantum state cross transmission in the butterfly network.
The above embodiments are provided to further illustrate the objects, technical solutions and advantages of the present invention. It should be understood that the above examples are only preferred embodiments of the present invention and are not intended to limit the present invention, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (1)
1. The safe quantum network coding method based on quantum homomorphic encryption improves the transmission safety of a quantum state to be transmitted in a butterfly network and is characterized by comprising the following steps:
step one: sender A through two rounds of quantum invisible state transmission processes 1 And A 2 Transferring the information of the quantum states to be transmitted to the opposite side, namely A 1 The entangled quantum state in the hand will become A 2 To be transmitted of quantum state information, A 2 The entangled quantum state in the hand will become A 1 To be transmitted with quantum state information, and A 1 And A 2 Measurement results of a group of classical bit sequences are also obtained respectively;
step two: sender a based on the respective measurements 1 And A 2 Respectively executing corresponding unitary operation on the quantum states to be transmitted in the hands of the user to obtain encrypted quantum states to be transmitted;
step three: sender A 1 And A 2 Respectively quantizing classical bit sequences of the respective measurement results to obtain measurement quantum states; in addition, A 2 Encrypting the measurement quantum state in the hand by using the encryption key to obtain an encrypted measurement quantum state;
step four: sender A 1 Measured quantum state of (c) and sender a 2 Is transmitted to the intermediate node C through the channel 1 And A is 2 Transmitting the encryption key to A through quantum key distribution technology 1 The method comprises the steps of carrying out a first treatment on the surface of the In addition to A 1 Transmitting the encrypted quantum state to be transmitted and the encryption key to the receiver B 2 ，A 2 Transmitting the encrypted quantum state to be transmitted and the encryption key to the receiver B 1 ；
Step five: intermediate node C 1 For sender A 1 Measured quantum state of (c) and sender a 2 The encrypted measurement quantum state of (2) is subjected to controlled unitary operation, and the obtained new measurement quantum state is sent to an intermediate node C 2 ；
Step six: intermediate node C 2 Copying the new measured quantum state, and respectively transmitting the new measured quantum state and the copied new measured quantum state to the receiver B 1 And B 2 ；
Step seven: according to intermediate node C 2 New measured quantum state and sender a 2 Is the encryption key of receiver B 1 Performing decryption operation on the new measurement quantum state to obtain a decrypted measurement quantum state; based on the measured quantum state information, B 1 For the A 2 Decrypting the encrypted quantum state to be transmitted, and recovering to obtain a sender A 1 To be transmitted;
step eight: likewise, according to intermediate node C 2 Replication of the resulting new measured quantum states and sender A 1 Is the encryption key of receiver B 2 Decrypting the copied new measurement quantum state to obtain a decrypted measurement quantum state; further, from the decrypted information of the measured quantum state, B 2 Pair A 1 The encrypted quantum state to be transmitted of (2) is also subjected to corresponding decryption operation to recover and obtain a sender A 2 To be transmitted.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102833265A (en) * | 2012-09-13 | 2012-12-19 | 北京航空航天大学 | Network theory based signature scheme and secure linear network encoding method thereof |
| CN104780169A (en) * | 2015-04-08 | 2015-07-15 | 北京航空航天大学 | Quantum repeater network coding scheme based on controller |
| JP2015220621A (en) * | 2014-05-19 | 2015-12-07 | 日本電信電話株式会社 | Multicast quantum network coding method |
| CN105978659A (en) * | 2016-04-18 | 2016-09-28 | 苏州大学 | Remote preparation quantum state based network coding method |
| CN109379144A (en) * | 2018-11-27 | 2019-02-22 | 北京航空航天大学 | A kind of quantum network coding method detuning based on quantum |
| CN110768793A (en) * | 2019-10-15 | 2020-02-07 | 国网甘肃省电力公司信息通信公司 | Two-stage quantum state cooperative multicast method based on butterfly network structure |
| US10630478B1 (en) * | 2018-12-28 | 2020-04-21 | University Of South Florida | Sender optimal, breach-resilient, and post-quantum secure cryptographic methods and systems for digital auditing |
| CN111064568A (en) * | 2019-12-03 | 2020-04-24 | 北京易华录信息技术股份有限公司 | Flow control method and device for quantum key distribution network |
| CN111130771A (en) * | 2019-12-24 | 2020-05-08 | 北京邮电大学 | Quantum network coding method based on quantum state non-loss |
-
2021
- 2021-09-26 CN CN202111133347.XA patent/CN113872748B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102833265A (en) * | 2012-09-13 | 2012-12-19 | 北京航空航天大学 | Network theory based signature scheme and secure linear network encoding method thereof |
| JP2015220621A (en) * | 2014-05-19 | 2015-12-07 | 日本電信電話株式会社 | Multicast quantum network coding method |
| CN104780169A (en) * | 2015-04-08 | 2015-07-15 | 北京航空航天大学 | Quantum repeater network coding scheme based on controller |
| CN105978659A (en) * | 2016-04-18 | 2016-09-28 | 苏州大学 | Remote preparation quantum state based network coding method |
| CN109379144A (en) * | 2018-11-27 | 2019-02-22 | 北京航空航天大学 | A kind of quantum network coding method detuning based on quantum |
| US10630478B1 (en) * | 2018-12-28 | 2020-04-21 | University Of South Florida | Sender optimal, breach-resilient, and post-quantum secure cryptographic methods and systems for digital auditing |
| CN110768793A (en) * | 2019-10-15 | 2020-02-07 | 国网甘肃省电力公司信息通信公司 | Two-stage quantum state cooperative multicast method based on butterfly network structure |
| CN111064568A (en) * | 2019-12-03 | 2020-04-24 | 北京易华录信息技术股份有限公司 | Flow control method and device for quantum key distribution network |
| CN111130771A (en) * | 2019-12-24 | 2020-05-08 | 北京邮电大学 | Quantum network coding method based on quantum state non-loss |
Non-Patent Citations (1)
| Title |
|---|
| 基于蝶型网络模型的量子网络编码;张璇;施荣华;郭迎;;计算机应用研究(03);全文 * |
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