Risk degree calculation method for nodes, transmission lines and paths in quantum communication network

Abstract

The invention discloses a risk degree calculation method especially suitable for a network node, a transmission line and a transmission path in a quantum communication network. In addition to considering the influence of the overall layout of the network on the risk degree of network nodes and transmission lines, a dynamic consideration factor of the risk degree is provided based on an information transmission process and a final transmission result, and a specific calculation mode conforming to the network is given, so that the risk degree can be accurately calculated while normal information transmission is carried out. The network risk degree is accurately and dynamically mastered by using the transmission result of the self-inspection information, the dynamic monitoring of the network risk is realized, and a powerful guarantee is provided for planning an optimal information transmission path.

Description

Technical Field

[0001] The present invention relates to the field of secure communication technology, and in particular to a method for calculating the risk of network nodes, transmission lines and transmission paths in a quantum communication network that is particularly suitable (allowing secure self-checking). Background Art

[0002] In the information age, information security is receiving more and more attention, and the assessment and detection of network security has become an important topic.

[0003] The current network transmission method is based on classical information. When there is an eavesdropper in the network, because the eavesdropper can copy the classical information without changing the information content, the traditional network self-check method can only target the destroyer who changes the transmission information. It is difficult to detect the eavesdropper who does not change the transmission information but only copies the information. Summary of the invention

[0004] In view of the above problems in the prior art, the present invention discloses a method for calculating the risk of network nodes, transmission lines and transmission paths that is particularly suitable for quantum communication networks. In addition to considering the impact of the overall network layout on the risk of network nodes and transmission lines, dynamic considerations of risk are proposed based on the information transmission process and the final transmission results, and a specific calculation method consistent with the network (allowing security self-checking) is given, so that while normal information is transmitted, the transmission results of the self-checking information can be used to accurately and dynamically grasp the risk of the network, realize dynamic monitoring of network risks, and provide a strong guarantee for planning the best information transmission path.

[0005] Specifically, a first aspect of the present invention relates to a risk calculation method for a network node of a quantum communication network, which comprises an initialization step, an error statistics step and a dynamic update step;

[0006] In the initialization step, according to the number P of neighboring network nodes of network node i in the quantum communication network i , calculate the risk r of network node i 0i =ln(1+P i );

[0007] In the error statistics step, the number of errors n related to network node i within the preset time t is counted. i ;

[0008] In the dynamic update step, after the preset time t has passed, according to the number of error reports n i , update the risk r of network node i ti , where: when n i = 0, r ti =r 0i *e -λtOtherwise, r ti =r 0i +a*n i 2 , λ and a are preset coefficients.

[0009] Furthermore, in the error statistics step, when a network node on the transmission path receives information transmitted by the previous network node and reports an error based on the classical information therein, the number of errors associated with the previous network node is increased by 1; when the target network node reports an error based on the received quantum state information, the number of errors associated with each of the intermediate network nodes between the initial network node and the target network node on the transmission path is increased by 1.

[0010] Furthermore, the classic information includes the initial network node, the target network node, the intermediate network node list, the next network node, the digital signature and the timestamp of the network node, and the network node reports an error when it determines based on the classic information that there is at least one of a transmission path error, the difference between the timestamp and the current time exceeds a preset value, the digital signature does not match, and the classic information format is incorrect.

[0011] Furthermore, the quantum state information is generated based on the coded information, which includes the information to be transmitted, the digital signature and timestamp of the initial network node, and a hash value generated about one or more of the information to be transmitted, the digital signature and timestamp of the initial network node; and the target network node obtains the coded information when measuring the quantum state information and reports an error if the verification of the coded information fails.

[0012] Furthermore, the verification of the encoded information includes one or more of public comparison of the information to be transmitted, verification of the digital signature of the initial network node, verification of the timestamp, and verification of the hash value.

[0013] Furthermore, the information is transmitted between the initial network node and the target network node through the initial transmission process and the retransmission process;

[0014] In the initial transmission process, the initial network node generates original quantum state information based on the information to be transmitted, uses quantum logic gates to perform encryption operations on the original quantum state information to generate first quantum state information, calculates the transmission path with the minimum risk, and transmits the first quantum state information to the target network node according to the transmission path with the minimum risk; and the target network node uses quantum logic gates to perform encryption operations on the first quantum state information to generate second quantum state information, calculates the transmission path with the minimum risk, and transmits the second quantum state information back to the initial network node according to the transmission path with the minimum risk;

[0015] During the retransmission process, the initial network node uses a quantum logic gate to perform a decryption operation on the second quantum state information to generate a third quantum state information, calculates a transmission path with the minimum risk, and transmits the third quantum state information to the target network node according to the transmission path with the minimum risk; and the target network node uses a quantum logic gate to perform a decryption operation on the third quantum state information to generate a fourth quantum state information, and measures the fourth quantum state information to obtain the transmitted information;

[0016] The encryption operation during the initial transmission process and the decryption operation during the retransmission process of the same network node cancel each other out in terms of their effects on the quantum state information.

[0017] A second aspect of the present invention relates to a method for calculating the risk of a transmission line between network nodes in a quantum communication network, which comprises an initialization step, an error statistics step and a dynamic update step;

[0018] In the initialization step, according to the line length L of the transmission line ij between two adjacent network nodes in the quantum communication network ij , calculate the risk of transmission line ij μ is the preset coefficient;

[0019] In the error statistics step, the number of errors m related to the transmission line ij within the preset time t is counted. ij ;

[0020] In the dynamic update step, after the preset time t has passed, according to the number of error reports m ij , update the risk r of transmission line ij tij , where: when m ij = 0, r tij =r 0ij *e -λt , otherwise, r tij =r 0ij +b*m ij 2 , λ and b are preset coefficients.

[0021] Furthermore, in the error statistics step, when a network node on the transmission path receives information transmitted by the previous network node and reports an error based on the classical information therein, the number of errors of the previous transmission line is increased by 1; when the target network node reports an error based on the received quantum state information, the number of errors associated with each of all transmission lines on the transmission path is increased by 1.

[0022] Furthermore, the classic information includes the initial network node, the target network node, the intermediate network node list, the next network node, the digital signature and the timestamp of the network node, and the network node reports an error when it determines based on the classic information that there is at least one of a transmission path error, the difference between the timestamp and the current time exceeds a preset value, the digital signature does not match, and the classic information format is incorrect.

[0023] Furthermore, the quantum state information is generated based on the coded information, which includes the information to be transmitted, the digital signature and timestamp of the initial network node, and a hash value generated about one or more of the information to be transmitted, the digital signature and timestamp of the initial network node; and the target network node obtains the coded information when measuring the quantum state information and reports an error if the verification of the coded information fails.

[0024] Furthermore, the verification of the encoded information includes one or more of public comparison of the information to be transmitted, verification of the digital signature of the initial network node, verification of the timestamp, and verification of the hash value.

[0025] Furthermore, the information is transmitted between the initial network node and the target network node through the initial transmission process and the retransmission process;

[0026] In the initial transmission process, the initial network node generates original quantum state information based on the information to be transmitted, uses quantum logic gates to perform encryption operations on the original quantum state information to generate first quantum state information, calculates the transmission path with the minimum risk, and transmits the first quantum state information to the target network node according to the transmission path with the minimum risk; and the target network node uses quantum logic gates to perform encryption operations on the first quantum state information to generate second quantum state information, calculates the transmission path with the minimum risk, and transmits the second quantum state information back to the initial network node according to the transmission path with the minimum risk;

[0027] During the retransmission process, the initial network node uses a quantum logic gate to perform a decryption operation on the second quantum state information to generate a third quantum state information, calculates a transmission path with the minimum risk, and transmits the third quantum state information to the target network node according to the transmission path with the minimum risk; and the target network node uses a quantum logic gate to perform a decryption operation on the third quantum state information to generate a fourth quantum state information, and measures the fourth quantum state information to obtain the transmitted information;

[0028] The encryption operation during the initial transmission process and the decryption operation during the retransmission process of the same network node cancel each other out in terms of their effects on the quantum state information.

[0029] A third aspect of the present invention relates to a method for calculating the risk of a transmission path used in a quantum communication network, wherein the risk of the transmission path between an initial network node and a target network node is the sum of the risks of all network nodes on the transmission path and the risks of all transmission lines; and the risk of the network node is calculated using the above-mentioned network node risk calculation method, and the risk of the transmission line is calculated using the above-mentioned transmission line risk calculation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. It is obvious that the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 Schematically shows a network architecture that allows security self-checking according to the present invention;

[0033] Figure 2 An example of a network node according to the present invention is schematically shown;

[0034] Figure 3 The encryption / decryption principle of the quantum encryption / decryption module according to the present invention is schematically shown;

[0035] Figure 4 An example of an analysis module according to the present invention is schematically shown;

[0036] FIG5( a) schematically shows an example of a self-test information transmission method according to the present invention;

[0037] FIG5( b ) schematically shows the transmission path of a single quantum bit in the self-checking information transmission method according to the present invention. DETAILED DESCRIPTION

[0038] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided by way of example so as to fully convey the spirit of the present invention to those skilled in the art to which the present invention belongs. Therefore, the present invention is not limited to the embodiments disclosed herein.

[0039] Figure 1The network architecture that allows safe self-checking according to the present invention is schematically shown, which includes multiple network nodes, such as node 1, ..., node 7, and each network node is connected through a quantum channel and a classical channel, so that any two network nodes in the network can directly or indirectly realize data connection and interact with quantum state information and classical information.

[0040] Figure 2 An example of a network node used for the present invention is shown.

[0041] As shown in the figure, the network node may include a receiving end, a quantum state generation module, a quantum state measurement module, a quantum encryption / decryption module, a control module, an analysis module and a sending end.

[0042] In the network node, the information to be transmitted may first be encoded to form encoded information. As an example, the encoded information may include, in addition to the information to be transmitted, verification data such as a digital signature of the network node, a timestamp, and a hash value for verifying the integrity of the information.

[0043] The quantum state generation module is used to generate quantum state information based on the encoded information, which may include multiple quantum bits. As an example, the quantum state generation module can be implemented with the help of a quantum state generation device.

[0044] The quantum state measurement module is used to measure quantum state information to obtain coded information, thereby allowing information to be transmitted, that is, actually received information, to be obtained from the coded information. As an example, the quantum state measurement module can be implemented with the aid of a quantum state measurement device.

[0045] The quantum encryption / decryption module is used to encrypt / decrypt quantum state information. The quantum encryption / decryption module here does not use traditional (shared) keys for encryption / decryption processing, but uses quantum logic gates to encode logical operations on quantum state information (quantum bits) to change the quantum state and achieve encryption or decryption of quantum state information. Among them, by using adjustable quantum logic gates in the quantum encryption / decryption module, it is allowed to control the quantum logic gates to achieve switching between encryption operations and decryption operations.

[0046] In a preferred example, the quantum logic gates used in the quantum encryption / decryption modules of different network nodes may be different from each other.

[0047] In the present invention, by controlling the quantum logic gate, the encryption operation and decryption operation of the quantum encryption / decryption module of the same network node cancel each other out in terms of the transformation effects on the quantum state.

[0048] Preferably, the quantum logic gate Where, the phase θ j is the quantum logic gate U(θj ) is an adjustment parameter. That is, the phase θ j To adjust the quantum logic gate U(θ j ), thereby realizing the switch between encryption and decryption operations. Among them, the quantum logic gate U(θ j ) of the phase θ j Can be different from each other.

[0049] In a preferred example, the quantum encryption / decryption module may include a set of quantum logic gates {U(θ j )}, j = 1, ... Therefore, when the quantum state information is input into the quantum encryption / decryption module, the i-th quantum bit in the quantum state information It can be represented by a quantum logic gate {U(θ j )} in the jth quantum logic gate U(θ j ) to perform encoding logic operations The quantum state is changed, thereby realizing the encryption / decryption of the entire quantum state information. Figure 3 As shown, the i=1th quantum bit in the quantum state information The j=1th quantum logic gate U(θ1) is used to calculate i = 2 qubits The j=2nd quantum logic gate U(θ2) is used to calculate i = 3 qubits The j=3rd quantum logic gate U(θ3) is used to calculate By using quantum logic gates of this specific structure, it is possible to perform phase-adjustable single-bit encoding operations on quantum bits in quantum state information, so that the encryption of quantum state information can be exchanged in order, which can adapt to the ring information transmission structure mentioned below while using the non-replicability of quantum to protect the security of encrypted information.

[0050] In the present invention, the control module is configured to control the quantum logic gates in the quantum encryption / decryption module to achieve switching between encryption operations and decryption operations based on the quantum logic gates.

[0051] Preferably, the control module may include a phase controller for controlling the quantum logic gate U(θ j )’s adjustment parameter phase θ j .

[0052] In a preferred example, the control module can control the quantum logic gate U(θ j ) at phase θ j Next pair of qubits Perform encoding logic operations and encrypt them; when the encrypted quantum bits are expected to When decrypting, control the quantum logic gate U(θ j ) of the phase θ j Reverse to -θ j , using quantum logic gate U(-θ j ) for quantum bits Perform encoding logic operations. Therefore, under this decryption operation, the quantum logic gate U(θ j ) for quantum bits The encryption function restores the quantum bit

[0053] Here, those skilled in the art will appreciate that the quantum operation device for implementing the quantum logic gate can be selected according to the carrier of the quantum bit. When the carrier is pulse light, the pulse light can be passed through a polarizer in a specific direction to realize the quantum logic gate U(θ j ) for quantum bits The phase controller can control the quantum logic gate U(θ j ) in the phase parameter θ j .

[0054] Continue to see Figure 2 The receiving end can be used to receive information transmitted by other network nodes, which includes classical information and quantum state information. As an example, the receiving end can be implemented by means of a receiving device for quantum state information and classical information.

[0055] When the receiving end receives the classical information and quantum state information, it can send the quantum state information to the quantum encryption / decryption module for encryption or decryption operations, and send the classical information to the analysis module.

[0056] The analysis module is used to read, write and analyze classical information, as well as calculate the transmission path of information.

[0057] In the present invention, classical information may include data related to the information transmission process, such as a status identifier and a node list, wherein the status identifier includes an initial transmission status and a retransmission status, and the node list includes information related to the transmission path such as an initial network node, a target network node, an intermediate network node, and a next network node.

[0058] like Figure 4 As shown, the analysis module may include a read-write unit, a processing unit, a risk calculation unit, and a path calculation unit.

[0059] The read / write unit is used for reading and writing classical information, such as reading status identifiers and node lists, changing status identifiers, writing node list data, etc.

[0060] The processing unit is used to determine the operation to be performed based on the classical information read by the read-write module, and to provide the digital signature and timestamp of the network node.

[0061] The risk calculation unit is used to calculate the risk of the network in real time. The risk is related to factors such as the number of network nodes, the distance between network nodes, the security of the lines between network nodes, and the confidentiality of each network node, and satisfies the following properties: Let R AB is the risk between network nodes A and B, C is another network node, then R AB ≤R AC +R BC , and the equality sign is obtained if and only if network node C is on the transmission path with the minimum risk between network nodes A and B.

[0062] The path calculation unit is used to calculate the best transmission path of the network node according to the risk, such as the transmission path with the minimum risk.

[0063] The transmitting end can be used to integrate the classical information and the quantum state information and transmit them together to the next network node. As an example, the transmitting end can be implemented by means of a classical information transmitter and a quantum state information transmitter.

[0064] In order to better understand the structure and function of each module and unit in the network proposed by the present invention, the following will be combined with Figure 5(a)-5(b) The self-check information transmission method for a network that allows security self-check of the present invention is described, and is particularly suitable for use in the network that allows security self-check.

[0065] As shown in FIG. 5( a ), the self-test information transmission method of the present invention takes the transmission of self-test information from the initial network node A to the target network node B as an example, including an initial transmission process and a retransmission process.

[0066] In the initial transmission process, after the initial network node A generates the original quantum state information based on the information to be transmitted (such as self-test information), it independently uses the quantum logic gate to perform encryption operation on the original quantum state information to generate the first quantum state information, and generates the minimum risk transmission path for the target network node B based on the risk, so as to transmit the first quantum state information to the target network node B according to the minimum risk transmission path. After receiving the first quantum state information, the target network node B will also independently use the quantum logic gate to perform encryption operation on the first quantum state information to generate the second quantum state information, and generate the minimum risk transmission path for the initial network node A based on the risk, so as to transmit the second quantum state information back to the initial network node A according to the minimum risk transmission path. In this way, it can be ensured that in the initial transmission process, the quantum state information carrying the information to be transmitted is always in an encrypted state.

[0067] During the retransmission process, the initial network node A again independently uses the quantum logic gate to perform a decryption operation on the second quantum state information to generate the third quantum state information, and regenerates the minimum risk transmission path for the target network node B based on the risk, so as to transmit the third quantum state information to the target network node B according to the minimum risk transmission path. After receiving the third quantum state information, the target network node B also independently uses the quantum logic gate to perform a decryption operation on the third quantum state information to generate the fourth quantum state information, and then measures the fourth quantum state information to obtain the plaintext of the received information.

[0068] It can be noted that in the self-test information transmission method of the present invention, the quantum state information first undergoes encryption operations in the initial network node A and the target network node B respectively, and then undergoes decryption operations in the initial network node A and the target network node B respectively, and finally undergoes the same number of encryption and decryption operations in the same network node. Therefore, it is possible to simply control the quantum logic gates used to implement encryption and decryption operations in the network nodes so that the effects of the decryption operations and encryption operations on the same quantum state information performed by the quantum logic gates in the same network node (for example, the initial network node A, the target network node B) are offset by each other. Therefore, there is no need for the network nodes to use shared keys, so that the quantum state information related to the information to be transmitted can be ensured to be always in an encrypted state during the transmission process, and when it is transmitted to the target network node again, it can be automatically restored to plain text with the help of the decryption operation at the target network node.

[0069] Specifically referring to FIG. 5( a ), the initial sending process involves state 1 and state 2, and the resending process involves state 3 and state 4.

[0070] In state 1, the initial network node A calculates the optimal transmission path target to reach the target network node B with the help of its analysis module.

[0071] In the present invention, in order to evaluate the confidentiality of the transmission path, the risk between network nodes is used to describe the possibility of information leakage when two network nodes communicate through the most secure transmission path. Therefore, the analysis module of the initial network node A can use, for example, the Dijkstra algorithm to calculate the transmission path with the minimum risk to the target network node B, so as to realize the information transmission from the initial network node A to the target network node B according to the transmission path with the minimum risk.

[0072] The initial network node A also generates quantum state information related to the information to be transmitted. To this end, the initial network node A can first encode the information to be transmitted to generate coded information, and then use the quantum state generation module to generate original quantum state information based on the coded information.

[0073] In the present invention, in order to enable the target network node B to confirm the authenticity of the received information, the encoded information may include, in addition to the information to be transmitted (text), the digital signature of the initial network node A, a timestamp, and verification data such as a hash value generated as a whole about the information to be transmitted, the digital signature and the timestamp, as shown in the following table:

[0074] Information to be transmitted Digital signature of the initial network node Timestamp Hash value

[0075] Therefore, when the target network node B obtains the coded information transmitted by the initial network node A, it can verify the authenticity and integrity of the information to be transmitted (self-test information) contained in the coded information it obtains through data such as the hash value, the digital signature and timestamp of the initial network node A.

[0076] As mentioned above, to facilitate process control, network nodes can read, write and analyze classical information through their analysis modules, which includes status identification and node lists.

[0077] The state identifier is used to identify the current transmission state of the quantum state information. For example, "initial transmission state" indicates that the current transmission of the quantum state information is in the initial transmission process, and "retransmission state" indicates that the current transmission of the quantum state information is in the retransmission process.

[0078] The node list is used to record data related to the calculated optimal transmission path (transmission path with the lowest risk), such as the initial network node A, the target network node B, the intermediate network node and the next intermediate network node.

[0079] Furthermore, during the initial transmission process, the network node can also use its analysis module to write a timestamp in the classical information, thereby allowing the next network node to determine whether the information transmission between the two network nodes is normal based on the timestamp in the classical information when receiving the quantum state information and the classical information.

[0080] For example, in state one involving the initial sending process, when the initial network node A generates classic information, it identifies the "state identifier" therein as "initial sending state", records the initial network node A, the target network node B, and the intermediate network nodes other than the initial network node A and the target network node B on the transmission path with the lowest risk, and records the next network node about the initial network node A on the transmission path with the lowest risk at the "next network node", such as "network node C1", and an additional timestamp.

[0081] In addition, to ensure the security of information transmission, the initial network node A will also encrypt the original quantum state information to generate the first quantum state information. To this end, the initial network node A can use the control module to pre-set the quantum logic gate U(θ Aj ), so that after the original quantum state information is generated, the original quantum state information is encrypted by means of the quantum encryption / decryption module to generate the first quantum state information. Among them, a set of quantum logic gates {U(θ Aj )} for the quantum bits in the original quantum state information The encoding logic operation is performed as shown in FIG5(b).

[0082] Finally, the first quantum state information (ie, the original quantum state information encrypted once) and the classical information can be integrated at the sending end and sent to the next network node.

[0083] In state two, after receiving the first quantum state information and the classical information, the target network node B can first read the classical information through its analysis module.

[0084] After the analysis module confirms that it is the target network node for this information transmission by reading information such as the initial network node A and the target network node B in the classic information, it can change the state identifier from the initial sending state to the resending state, and use, for example, the Dijkstra algorithm to calculate the transmission path with the minimum risk to the initial network node A, and send the transmission path with the minimum risk to the sending end as the optimal transmission path from the target network node B to the initial network node A.

[0085] The analysis module of the target network node B can also determine whether the current transmission process is normal by reading the timestamp in the classic information and comparing it with the current time. When it is determined that the difference between the read timestamp and the current time is less than the set value, it is allowed to update the timestamp and write the calculated transmission path with the minimum risk into the classic information.

[0086] Similarly, the target network node B will also use the control module to pre-set the quantum logic gate U(θ Bj), as shown in FIG5(b), the quantum encryption / decryption module is used to perform encryption operation on the quantum bits in the first quantum state information to generate Thereby, the second quantum state information is obtained, which contains the original state information encrypted twice.

[0087] Finally, the second quantum state information and the classical information can be integrated at the sending end and sent to the initial network node A according to the determined transmission path with the lowest risk.

[0088] At this point, the initial sending process of quantum state information is completed.

[0089] In state three, after receiving the second quantum state information and classical information returned by the target network node B, the initial network node A can use its analysis module to read the classical information.

[0090] After the analysis module reads the classical information and determines that the state identifier is the resending state and that the current network node is the initial network node, it can verify the digital signature of the target network node B in the classical information, and after the digital signature verification is passed, use the Dijkstra algorithm to recalculate its minimum risk transmission path to the target network node B, and send it to the sender as the optimal transmission path to allow the information to be retransmitted from the initial network node A to the target network node B according to the minimum risk transmission path.

[0091] The analysis module can also verify the timestamp in the classic information, and when the difference between the timestamp and the current time is less than a preset value, encode the classic information to update the timestamp, and write the recalculated transmission path with the minimum risk from the initial network node A to the target network node B into the classic information, and attach a digital signature at the initial network node A in the classic information.

[0092] In addition, the control module also controls the quantum logic gate in the quantum encryption / decryption module to reverse, for example, the phase parameter θ Aj Taking the opposite value, the quantum logic gate U(θ Aj ) becomes U(-θ Aj ), as shown in Figure 5(b), the encoding logic operation of the quantum logic gate on the quantum state information is switched to the decryption operation, and the encryption operation and decryption operation of the same network node cancel each other out. For example, U(θ Aj )U(-θ Aj )=I. Therefore, after the decryption operation at the initial network node A, the quantum state information about the quantum logic gate U(θ Aj ) is decrypted, and the quantum bits in the third quantum state information generated by the decryption operation can be expressed as

[0093] Preferably, after completing the quantum logic gate U(-θ Aj ) After decrypting the quantum state information, the control module can restore the quantum logic gate to its original state U(θ Aj ).

[0094] Finally, the sender integrates the third quantum state information and classical information according to the transmission path with the lowest risk and sends them to the target network node B.

[0095] In state four, after receiving the third quantum state information and the classical information, the target network node B reads the state identifier in the classical information through its analysis module as a resending state.

[0096] At this time, the analysis module can verify the digital signature and timestamp of the initial network node A in the read classical information.

[0097] When the digital signature is verified and the difference between the timestamp and the current time is less than the preset value, the target network node B can use the control module to control the quantum logic gate in the quantum encryption / decryption module to reverse, for example, to make the phase parameter θ Bj Taking the opposite value, the quantum logic gate U(θ Bj ) becomes I(-θ Bj ), as shown in Figure 5(b), thereby switching the encoding logic operation of the quantum logic gate on the quantum state information to the decryption operation, and the encryption operation and decryption operation of the same network node on the quantum state information cancel each other out. For example, U(θ Bj )-(-θ Bj )=I. Therefore, after the decryption operation at the target network node B, the third quantum state information about the quantum logic gate U(θ Bj ) is decrypted, and the quantum bits in the quantum state information are restored to Therefore, the quantum state information encrypted during the initial transmission process can be restored to its plaintext, that is, the original quantum state information, when it is transmitted to the target network node B again through the retransmission process. This process does not require the participation of a shared key.

[0098] Preferably, after completing the quantum logic gate U(-θ Bj ) After decrypting the quantum state information, the control module can restore the quantum logic gate to its original state U(θ Bj ).

[0099] Afterwards, the target network node B can use the quantum state measurement module to measure the decoded original quantum state information, obtain the encoded information, and parse the plaintext of the received (to be transmitted) information.

[0100] Among them, the target network node B can also verify the digital signature in the obtained coded information to ensure that the received information to be transmitted comes from the initial network node A, and verify the timestamp in the coded information based on the current time to ensure that the information transmission process is normal, and verify the hash value in the coded information to ensure the integrity of the received information. At this time, if the verification of the information to be transmitted fails, the target network node B can report an error, broadcast the error information, and increase the risk of all network nodes and lines on the transmission path at the next risk settlement.

[0101] Therefore, through the initial sending process and the resending process, the information to be transmitted is encrypted from the initial network node A to the target network node B in the form of a ring transmission. Only the logical operation of the quantum state information by quantum logic gates can be used without the participation of shared keys, thereby realizing the secure transmission of information (self-test information) between the initial network node A and the target network node B.

[0102] Furthermore, in the self-checking information transmission method of the present invention, after measuring the fourth quantum state information to obtain the information to be transmitted, the target network node B can also randomly select a number of bits from the received (to be transmitted) information for public comparison with the initial network node A. If the comparison fails, for example, the error rate exceeds a preset threshold, it means that there is a problem in the propagation process.

[0103] Furthermore, when a network node receives quantum state information and classical information from the previous network node, and discovers that it is a node other than the initial network node A and the target network node B by reading the classical information, it can determine whether it belongs to an intermediate network node on the recorded transmission path with the lowest risk based on the received classical information, and whether the received information comes from the previous network node about it on the transmission path with the lowest risk.

[0104] If it is determined that this network node is on the recorded transmission path with minimum risk, and the received information comes from the previous network node about it on the transmission path with minimum risk, the network node can update the next network node in the classical information according to the recorded transmission path with minimum risk, send the received quantum state information and classical information to the next network node about it, and broadcast to the initial network node A and the target network node B.

[0105] When it is determined that the network node is not on the recorded transmission path with the lowest risk and / or the received information is not from the previous network node on the transmission path with the lowest risk, the transmission may be terminated and the error may be broadcasted.

[0106] In particular, referring to FIG5(a), the operation corresponding to the quantum logic gate selected by the target network node B can be an identity transformation or a Hadamard gate. Therefore, when the initial network node A prepares a photon of the |HV> basis, if the target network node B in state two is encrypted by the identity transformation, then the target network node B in state four is equivalent to being measured by the |HV> basis; if the target network node B in state two is encrypted by the Hadamard gate, then the target network node B in state four is equivalent to being measured by the |+-> basis. In this way, the channel security of the BB84 protocol can be detected.

[0107] In summary, in the network that allows secure self-checking and the self-checking information transmission method thereof of the present invention, a ring-shaped information transmission path is adopted to realize that the initial network node and the target network node can perform encryption and decryption without knowing each other about the key used for encryption and decryption (such as the phase parameter in the quantum logic gate), thereby realizing encrypted transmission of information. In addition, in the encryption and decryption operation for encrypted information transmission, due to the use of quantum logic gates with a specific structure, a phase-adjustable single-bit encoding operation can be performed on a group of quantum bits in sequence, so that the encryption of the quantum state can be exchanged in order, and the security of the encrypted information is protected by the non-replicability of the quantum while adapting to the ring-shaped information transmission structure. The security of the network is guaranteed by the non-replicability and unpredictability of the quantum state. If an eavesdropper wants to know the content of the encrypted quantum information, he needs to know the measurement basis, that is, he needs to know the phase values ​​of all the nodes he has experienced. In particular, he needs to know the phase value of the initial network node A, which is equivalent to the direct leakage of the information of the initial network node A. In addition, in practical applications, even if the quantum state information received and transmitted by a node is intercepted, because the measurement basis is unknown, it is impossible to obtain the phase value of the quantum logic gate used by the node through quantum state comparison, and it is impossible to obtain the detection information without leaving a trace, thereby allowing potential eavesdroppers to be found through this self-detection method.

[0108] In the above description of the quantum communication network and the self-checking information transmission method, the content of determining the information transmission path based on the risk of the network is mentioned, and the considerations related to the risk are discussed in detail, such as the risk and the number of network nodes passed through, the distance between network nodes, the security of the lines between network nodes, the confidentiality of network nodes, etc. Although those skilled in the art can think of various specific risk calculation schemes based on the above content, the inventor, through further creative work, also proposes a method that is particularly suitable for calculating the risk of network nodes, transmission lines and transmission paths using self-checking information (i.e., information to be transmitted) in the scenario where self-checking information is transmitted between the initial network node and the target network node using the above self-checking information transmission method. Of course, this risk calculation method may also be applicable to other scenarios.

[0109] The risk calculation method of the present invention may include an initialization step, an error statistics step and a dynamic update step.

[0110] The initialization step is used to calculate the initial value of the risk of each network node and transmission line (ie, the line between adjacent network nodes) according to the network layout (eg, the network allowing safety self-checking of the present invention).

[0111] Specifically, for any network node i in the network, according to the relationship r 0i =ln(1+P i ) Calculate the initial value of its risk r 0i , where P i is the number of adjacent network nodes of network node i in the network.

[0112] For the transmission line ij between any two adjacent network nodes i and j in the network, it can be Calculate the initial value of its risk r 0ij , where L ij is the line length of the transmission line ij, and μ is a preset coefficient.

[0113] On the basis of obtaining the initial values ​​of the risks of the network nodes and transmission lines, in order to make the obtained risks match the real situation of the network in real time, the present invention also counts the occurrence of errors related to each network node and transmission line within a period of time during the information transmission process in the error statistics step, so as to dynamically adjust the risk of each network node and transmission line accordingly. At the same time, the error can also be broadcast to the entire network.

[0114] According to the present invention, in the error statistics step, when quantum state information is transmitted via the network, classical information such as the information transmission path (i.e., the network nodes and transmission lines through which the information is transmitted) can be recorded simultaneously, so that during the information transmission process, each network node in the path can detect errors in the current information transmission by checking, for example, classical information, or the target network node can detect errors in the information transmission result by checking, for example, quantum state information, and adjust the risk of the corresponding network nodes and transmission lines based on different error types.

[0115] Specifically, as described above in the network and self-checking information transmission method, in the process of information transmission, quantum state information and classical information can be integrated for transmission. Wherein, quantum state information can be generated based on coded information, and the coded information, in addition to the information to be transmitted, can also include, for example, the digital signature of the initial network node, a timestamp, and verification data such as a hash value generated about one or more of the information to be transmitted, the digital signature of the initial network node, and the timestamp; classical information can be used to record data related to the information transmission process and some related verification data, such as the initial network node, the target network node, the intermediate network node (list), the next network node, and the digital signature and timestamp of the network node.

[0116] Therefore, during the information transmission process, when network node i receives the quantum state information and classical information transmitted by the previous network node, since the quantum state information may be in an encrypted state at this time, network node i can read the classical information and check whether there are problems in the transmission process between it and the previous network node, such as transmission path error, the difference between the timestamp and the current time exceeds the preset value, the digital signature does not match, the classical information format error, etc., based on the data such as the initial network node, the target network node, the intermediate network node, the next network node, the digital signature and the timestamp recorded therein. When such problems occur, the number of error reports related to the previous network node and the number of error reports related to the previous transmission line (i.e., the transmission line from the previous network node to the current network node i) are increased, for example, the number of error reports is increased by 1.

[0117] In addition, when quantum state information is sent to a target network node, for example, through an initial transmission process and a retransmission process, the target network node can obtain corresponding coded information, for example, through a decryption measurement operation, and then publicly compare some bits of the received information to be transmitted with the initial network node, verify the digital signature of the initial network node, verify the timestamp, and verify the hash value to check errors in the information transmission result. If such errors exist, the number of error reports associated with each of all intermediate network nodes and each of all transmission lines between the initial network node and the target network node on the transmission path can be increased, for example, the number of error reports can be increased by 1.

[0118] In the present invention, a statistical period t can be pre-set to count the number of error reports n related to each network node i within the period t. i and the number of errors m associated with each transmission line ij ij , so that every statistical period t, with the help of dynamic update steps, according to the number of error reports n i and m ij , and update the risk of corresponding network nodes and transmission lines.

[0119] In the dynamic update step, if the number of errors n related to network node i is counted within the current statistical period t i =0, then the risk of the network node i is updated to r ti =r 0i *e -λt , otherwise update the risk of network node i to r ti =r 0i +a*n i 2 , where λ and a are preset coefficients.

[0120] If within the current statistical period t, the number of errors related to the transmission line ij is counted m ij = 0, then the risk of the transmission line ij is updated to r tij =r 0ij *e -λt Otherwise, update the risk of transmission line ij to r tij =r 0ij +b*m ij 2 , where λ and b are preset coefficients.

[0121] After the risks of the network nodes and transmission lines are obtained, the risk of the transmission path from the initial network node to the target network node may be calculated, which is the sum of the risks of all network nodes and all transmission lines on the transmission path.

[0122] In summary, it can be seen that the risk calculation method of the present invention not only considers the impact of the overall network layout on the risk of network nodes and transmission lines, but also proposes dynamic considerations of risk based on the information transmission process and the final transmission results, and provides a specific calculation method that is particularly compatible with the quantum communication network of the present invention. This allows the risk of the network to be accurately and dynamically grasped while normal information is transmitted, using the transmission results of self-test information, thereby achieving dynamic monitoring of network risks and providing a strong guarantee for planning the optimal information transmission path.

[0123] Although the present invention has been described above through specific embodiments in conjunction with the accompanying drawings, those skilled in the art will readily recognize that the above embodiments are merely exemplary and are used to illustrate the principles of the present invention, and do not limit the scope of the present invention. Those skilled in the art may make various combinations, modifications and equivalent substitutions to the above embodiments without departing from the spirit and scope of the present invention.

Claims

1. A method for calculating the risk of a network node in a quantum communication network, comprising an initialization step, an error statistics step, and a dynamic update step; In the initialization step, according to the number P of neighboring network nodes of network node i in the quantum communication network i , calculate the risk r of network node i 0i =ln(1+P i ); In the error statistics step, the number of errors n related to network node i within the preset time t is counted. i ; In the dynamic update step, after the preset time t has passed, according to the number of error reports n i , update the risk r of network node i ti , where: when n i = 0, r ti =r 0i *e -λt ;otherwise , r ti =r 0i +a*n i 2 , λ and a are preset coefficients.

2. The risk calculation method according to claim 1, wherein: In the error statistics step, when a network node on the transmission path receives information transmitted by the previous network node and reports an error based on the classical information therein, the number of errors associated with the previous network node will be increased by 1; when the target network node reports an error based on the received quantum state information, the number of errors associated with each of the intermediate network nodes between the initial network node and the target network node on the transmission path will be increased by 1.

3. The risk calculation method according to claim 2, wherein: Classic information includes the initial network node, the target network node, the intermediate network node, the next network node, the digital signature of the network node, and the timestamp; The network node reports an error when it determines based on the classic information that there is at least one of a transmission path error, a difference between the timestamp and the current time exceeds a preset value, a digital signature does not match, and a classic information format error.

4. The risk calculation method according to claim 2, wherein: The quantum state information is generated based on the coded information, the coded information includes the information to be transmitted, the digital signature and the timestamp of the initial network node, and a hash value generated about one or more of the information to be transmitted, the digital signature and the timestamp of the initial network node; The target network node obtains the coded information by measuring the quantum state information and reports an error when the verification of the coded information fails.

5. The risk calculation method according to claim 4, wherein: Verification of the encoded information includes one or more of public comparison of the information to be transmitted, verification of the digital signature of the initial network node, verification of the timestamp, and verification of the hash value.

6. The risk calculation method according to claim 2, wherein: The information is transmitted between the initial network node and the target network node through the initial transmission process and the retransmission process; In the initial transmission process, the initial network node generates original quantum state information based on the information to be transmitted, uses quantum logic gates to perform encryption operations on the original quantum state information to generate first quantum state information, calculates the transmission path with the minimum risk, and transmits the first quantum state information to the target network node according to the transmission path with the minimum risk; And, the target network node uses a quantum logic gate to perform an encryption operation on the first quantum state information to generate second quantum state information, calculates a transmission path with the minimum risk, and transmits the second quantum state information back to the initial network node according to the transmission path with the minimum risk; During the retransmission process, the initial network node uses a quantum logic gate to perform a decryption operation on the second quantum state information to generate a third quantum state information, calculates a transmission path with the minimum risk, and transmits the third quantum state information to the target network node according to the transmission path with the minimum risk; and the target network node uses a quantum logic gate to perform a decryption operation on the third quantum state information to generate a fourth quantum state information, and measures the fourth quantum state information to obtain the transmitted information; The encryption operation during the initial transmission process and the decryption operation during the retransmission process of the same network node cancel each other out in terms of their effects on the quantum state information.

7. A method for calculating the risk of transmission lines between network nodes in a quantum communication network, comprising an initialization step, an error statistics step, and a dynamic update step; In the initialization step, according to the line length L of the transmission line ij between two adjacent network nodes in the quantum communication network ij , calculate the risk of transmission line ij μ is the preset coefficient; In the error statistics step, the number of errors m related to the transmission line ij within the preset time t is counted. ij ; In the dynamic update step, after the preset time t has passed, according to the number of error reports m ij , update the risk r of transmission line ij tij , where: when m ij = 0, r tij =r 0ij *e -λt , otherwise, r tij =r 0ij +b*m ij 2 , λ and b are preset coefficients.

8. The risk calculation method according to claim 7, wherein: In the error statistics step, when a network node on the transmission path receives information transmitted by the previous network node and reports an error based on the classical information therein, the number of errors reported on the previous transmission line is increased by 1; when the target network node reports an error based on the received quantum state information, the number of errors associated with each of all transmission lines on the transmission path between the initial network node and the target network node is increased by 1.

9. The risk calculation method according to claim 8, wherein: The classic information includes the initial network node, the target network node, the intermediate network node, the next network node, the digital signature and the timestamp of the network node, and the network node reports an error when it determines based on the classic information that there is at least one of a transmission path error, the difference between the timestamp and the current time exceeds a preset value, the digital signature does not match, and the classic information format is incorrect.

10. The risk calculation method according to claim 8, wherein: The quantum state information is generated based on the coded information, the coded information includes the information to be transmitted, the digital signature and the timestamp of the initial network node, and a hash value generated about one or more of the information to be transmitted, the digital signature and the timestamp of the initial network node; And the target network node obtains the coded information by measuring the quantum state information, and reports an error when the verification of the coded information fails.

11. The risk calculation method according to claim 10, wherein: Verification of the encoded information includes one or more of public comparison of the information to be transmitted, verification of the digital signature of the initial network node, verification of the timestamp, and verification of the hash value.

12. The risk calculation method according to claim 8, wherein: The information is transmitted between the initial network node and the target network node through the initial transmission process and the retransmission process; In the initial transmission process, the initial network node generates original quantum state information based on the information to be transmitted, uses quantum logic gates to perform encryption operations on the original quantum state information to generate first quantum state information, calculates the transmission path with the minimum risk, and transmits the first quantum state information to the target network node according to the transmission path with the minimum risk; And, the target network node uses a quantum logic gate to perform an encryption operation on the first quantum state information to generate second quantum state information, calculates a transmission path with the minimum risk, and transmits the second quantum state information back to the initial network node according to the transmission path with the minimum risk; During the retransmission process, the initial network node uses a quantum logic gate to perform a decryption operation on the second quantum state information to generate a third quantum state information, calculates a transmission path with the minimum risk, and transmits the third quantum state information to the target network node according to the transmission path with the minimum risk; and the target network node uses a quantum logic gate to perform a decryption operation on the third quantum state information to generate a fourth quantum state information, and measures the fourth quantum state information to obtain the transmitted information; The encryption operation during the initial transmission process and the decryption operation during the retransmission process of the same network node cancel each other out in terms of their effects on the quantum state information.

13. A method for calculating the risk of a transmission path in a quantum communication network, wherein: The risk of the transmission path between the initial network node and the target network node is the sum of the risk of all network nodes on the transmission path and the risk of all transmission lines; and, Calculating the risk of a network node using the risk calculation method according to any one of claims 1 to 6; The risk of the transmission line is calculated using the risk calculation method described in any one of claims 7 to 12.

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