ABSTRACT
Abstract
An apparatus and method for multi-user quantum key distribution. The method for multi-user quantum key distribution is performed using a multi-user quantum key distribution apparatus and a quantum key client device, and includes generating, by the multi-user quantum key distribution apparatus, transmission qubit pairs based on a key bit string of a shared key to be distributed to the quantum key client device, measuring, by the quantum key client device, the transmission qubit pairs, received from the multi-user quantum key distribution apparatus through a quantum channel, based on a measurement basis, verifying security of the quantum channel using the transmission qubit pairs, and if the security has been verified, decoding qubit measurement values of the transmission qubit pairs into the shared key.
Description
CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of Korean Patent Application No. 10-2016-0114646, filed Sep. 6, 2016, which is hereby incorporated by reference in its entirety into this application.
This work was supported by the ICT R&D program of MSIP/IITP[1711028311, Reliable crypto-system standards and core technology development for secure quantum key distribution network] and the R&D Convergence program of NST (National Research Council of Science and Technology) of Republic of Korea (Grant No. CAP-18-08-KRISS).
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates generally to quantum communication technology and, more particularly, to quantum key distribution technology.
2. Description of the Related Art
Since conventional quantum key distribution techniques are designed to distribute a key only to a single user, they are not appropriate for achieving the object of distributing the same random key to a plurality of users.
However, in an actual key distribution environment, there are many cases where the same key is distributed to a plurality of users and is then used for the encryption systems of the users. A representative example of such encryption systems is an encryption system in which only users who are provided with the same key are capable of performing secure communication.
For example, conventional BB84-based quantum key distribution is a technique for guaranteeing secure key distribution between two users. For multi-user communication, when key distribution targets are extended to two or more users, the efficiency of distribution of the same random key is greatly deteriorated.
In order to solve this problem, conventional quantum key distribution techniques perform classical calculation and classical key distribution methods in a combined manner.
Meanwhile, Korean Patent No. 10-0596404 entitled âQuantum Key Distribution Method between Multiusers or Various Groupsâ discloses a method for generating a group key by preparing a number of multi-qubit entanglement states identical to the number of users connected to a center.
However, technology in Korean Patent No. 10-0596404 is difficult to actually implement from the standpoint of the use of multi-qubit entanglement states.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to distribute the same key to multiple users using a quantum technique, the security of which is proven.
Another object of the present invention is to guarantee constant key distribution efficiency, regardless of the number of users to whom the same key is to be distributed.
A further object of the present invention is to distribute the same key to multiple users in an actual key distribution environment by facilitating implementation using stable efficiency and a single qubit.
In accordance with an aspect of the present invention to accomplish the above objects, there is provided a method for multi-user quantum key distribution, the method being performed using a multi-user quantum key distribution apparatus and a quantum key client device, the method including generating, by the multi-user quantum key distribution apparatus, transmission qubit pairs based on a key bit string of a shared key to be distributed to the quantum key client device; measuring, by the quantum key client device, two qubits of each of the transmission qubit pairs, received from the multi-user quantum key distribution apparatus through a quantum channel, based two different measurement bases; verifying security of the quantum channel using verification qubit pairs in the transmission qubit pairs; and if the security has been verified, decoding measurement values of one qubit, in which a generation basis and a measurement basis are identical, in each transmission qubit pair into the shared key.
The method using the multi-user quantum key distribution apparatus and the quantum key client device may include generating, by the multi-user quantum key distribution apparatus, transmission qubit pairs based on a key bit string of a shared key to be distributed to the quantum key client device; measuring, by the quantum key client device, two respective qubits of each transmission qubit pair received from the multi-user quantum key distribution apparatus through a quantum channel in two different measurement bases; verifying security of the quantum channel using verification qubit pairs in the transmission qubit pair, and if the security is verified, decoding measurement values of one qubit, in which a generation basis is identical to a measurement basis, in each transmission qubit pair, into the shared key.
Generating the key qubit pairs may be configured to generate key qubit pairs, each including two identical key qubits for each key bit in the key bit string.
Generating the key qubit pairs may be configured to determine the two identical key qubits included in each key qubit pair based on both key values of the key bits and a generation basis corresponding to any one of a rectilinear basis and a diagonal basis.
Generating the key qubit pairs may be configured to determine an arrangement sequence of the generated key qubit pairs depending on an arrangement sequence of the key bits in the key bit string.
Generating the verification qubit pairs may be configured such that a number of transmission qubit pairs is greater than a number of key bits, and a number of verification qubit pairs to be generated is determined using a difference between the number of transmission qubit pairs and the number of key bits.
Generating the transmission qubit pairs based on the key qubit pairs and the verification qubit pairs may be configured to generate the transmission qubit pairs by arranging the verification qubit pairs at any one of arrangement locations respectively adjacent to the key qubit pairs and arrangement locations respectively adjacent to previously arranged verification qubit pairs.
Generating the transmission qubit pairs based on the key qubit pairs and the verification qubit pairs may be configured such that the multi-user quantum key distribution apparatus stores arrangement locations of the key qubit pairs and the verification qubit pairs arranged in each of the transmission qubit pairs.
Measuring the two qubits of each of the transmission qubit pairs may include receiving the generated transmission qubit pairs through the quantum channel; measuring the received transmission qubit pair in different measurement bases; and storing qubit measurement values of the transmission qubit pair.
Receiving the generated transmission qubit pairs may be configured such that the quantum key client device may receive arrangement locations and sequences of the key qubit pairs and the verification qubit pairs arranged in each of the transmission qubit pairs from the multi-user quantum key distribution apparatus.
Measuring the received transmission qubit pairs in different measurement bases may be configured such that the quantum key client device measures two qubits forming each transmission qubit pair by randomly selecting a sequence of the rectilinear measurement basis and the diagonal measurement basis.
Storing the qubit measurement values may be configured such that the quantum key client device stores the qubit measurement values that include both result values obtained by measuring each transmission qubit pair in the rectilinear basis and result values obtained by measuring each transmission qubit pair in the diagonal basis.
Verifying the security may be configured such that the multi-user quantum key distribution apparatus discloses states of verification qubits included in each transmission qubit pair, arrangement locations of the verification qubits, and a generation basis used to generate the verification qubits to the quantum key client device through a classical channel.
Verifying the security may be configured such that the quantum key client device determines, based on a comparison, whether measurement values in a measurement basis identical to the generation basis are identical to verification qubits, using the disclosed verification qubits, the arrangement locations of the disclosed verification qubits, and the generation basis of the disclosed verification qubits.
Verifying the security may be configured to, if it is determined that the qubit measurement results are identical to states of the verification qubits disclosed by the distribution apparatus, verify that the quantum channel is secure as a result of verification of security of the quantum channel.
Decoding the qubit measurement values may be configured such that, if it is verified that the quantum channel is secure as a result of verification of security of the quantum channel, the multi-user quantum key distribution apparatus discloses arrangement locations of key qubit pairs included in the transmission qubit pair and a generation basis used to generate the key qubit pairs to the quantum key client device through the classical channel.
Decoding the qubit measurement values may be configured such that, based on the disclosed arrangement locations of the key qubit pairs and the disclosed generation basis of the key qubit pairs, the quantum key client device decodes result values measured in a measurement basis identical to the generation basis into the key bit string of the shared key.
In accordance with another aspect of the present invention to accomplish the above objects, there is provided an apparatus for multi-user quantum key distribution, including a quantum random number generation unit for randomly generating a key bit string of a shared key to be distributed to quantum key client devices, based on quantum states; a qubit generation unit for generating transmission qubit pairs based on the key bit string; a qubit transmission unit for transmitting the transmission qubit pairs to the quantum key client device through a quantum channel; and a classical signal transmission/reception unit for disclosing information related to the transmission qubit pairs through a classical channel.
In accordance with a further aspect of the present invention to accomplish the above objects, there is provided a quantum key client device, including a qubit measurement unit for measuring transmission qubit pairs, received from a multi-user quantum key distribution apparatus through a quantum channel, based on a measurement basis; a quantum random number generation unit for selecting a sequence of measurement bases based on quantum states; a classical signal transmission/reception unit for receiving pieces of information related to the transmission qubit pairs through a classical channel; and a measurement result processing unit for determining, based on a comparison, whether the pieces of information related to the transmission qubit pairs are identical to qubit measurement values obtained by measuring the transmission qubit pairs, for verifying security of the quantum channel, and for decoding the qubit measurement values into a key bit string of a shared key to be distributed by the multi-user quantum key distribution apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a block diagram of an apparatus for multi-user quantum key distribution according to an embodiment of the present invention;
FIG. 2 is a table showing key qubit pairs according to an embodiment of the present invention;
FIGS. 3A and 3B are tables showing verification qubit pairs according to embodiments of the present invention;
FIG. 4 is a table showing transmission qubit pairs according to an embodiment of the present invention;
FIG. 5 is a diagram illustrating the distribution of the same key by the apparatus for multi-user quantum key distribution according to an embodiment of the present invention;
FIG. 6 is a graph showing a comparison in key distribution efficiency versus the number of users according to an embodiment of the present invention;
FIG. 7 is an operation flowchart illustrating a method for quantum key distribution according to an embodiment of the present invention;
FIG. 8 is an operation flowchart illustrating in detail an example of the transmission qubit pair generation step shown in FIG. 7 ;
FIG. 9 is an operation flowchart illustrating in detail an example of the transmission qubit pair measurement step shown in FIG. 7 ;
FIG. 10 is an operation flowchart illustrating in detail an example of the quantum channel security verification step shown in FIG. 7 ;
FIG. 11 is an operation flowchart illustrating in detail an example of the shared key decoding step shown in FIG. 7 ; and
FIG. 12 is a block diagram showing a computer system according to an embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described in detail below with reference to the accompanying drawings. Repeated descriptions and descriptions of known functions and configurations which have been deemed to make the gist of the present invention unnecessarily obscure will be omitted below. The embodiments of the present invention are intended to fully describe the present invention to a person having ordinary knowledge in the art to which the present invention pertains. Accordingly, the shapes, sizes, etc. of components in the drawings may be exaggerated to make the description clearer.
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.
FIG. 1 is a block diagram of an apparatus for multi-user quantum key distribution according to an embodiment of the present invention. FIG. 2 is a table showing key qubit pairs according to an embodiment of the present invention. FIGS. 3A and 3B are tables showing verification qubit pairs according to embodiments of the present invention. FIG. 4 is a table showing transmission qubit pairs according to an embodiment of the present invention. FIG. 5 is a diagram ill
CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of Korean Patent Application No. 10-2016-0114646, filed Sep. 6, 2016, which is hereby incorporated by reference in its entirety into this application.
This work was supported by the ICT R&D program of MSIP/IITP[1711028311, Reliable crypto-system standards and core technology development for secure quantum key distribution network] and the R&D Convergence program of NST (National Research Council of Science and Technology) of Republic of Korea (Grant No. CAP-18-08-KRISS).
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates generally to quantum communication technology and, more particularly, to quantum key distribution technology.
2. Description of the Related Art
Since conventional quantum key distribution techniques are designed to distribute a key only to a single user, they are not appropriate for achieving the object of distributing the same random key to a plurality of users.
However, in an actual key distribution environment, there are many cases where the same key is distributed to a plurality of users and is then used for the encryption systems of the users. A representative example of such encryption systems is an encryption system in which only users who are provided with the same key are capable of performing secure communication.
For example, conventional BB84-based quantum key distribution is a technique for guaranteeing secure key distribution between two users. For multi-user communication, when key distribution targets are extended to two or more users, the efficiency of distribution of the same random key is greatly deteriorated.
In order to solve this problem, conventional quantum key distribution techniques perform classical calculation and classical key distribution methods in a combined manner.
Meanwhile, Korean Patent No. 10-0596404 entitled âQuantum Key Distribution Method between Multiusers or Various Groupsâ discloses a method for generating a group key by preparing a number of multi-qubit entanglement states identical to the number of users connected to a center.
However, technology in Korean Patent No. 10-0596404 is difficult to actually implement from the standpoint of the use of multi-qubit entanglement states.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to distribute the same key to multiple users using a quantum technique, the security of which is proven.
Another object of the present invention is to guarantee constant key distribution efficiency, regardless of the number of users to whom the same key is to be distributed.
A further object of the present invention is to distribute the same key to multiple users in an actual key distribution environment by facilitating implementation using stable efficiency and a single qubit.
In accordance with an aspect of the present invention to accomplish the above objects, there is provided a method for multi-user quantum key distribution, the method being performed using a multi-user quantum key distribution apparatus and a quantum key client device, the method including generating, by the multi-user quantum key distribution apparatus, transmission qubit pairs based on a key bit string of a shared key to be distributed to the quantum key client device; measuring, by the quantum key client device, two qubits of each of the transmission qubit pairs, received from the multi-user quantum key distribution apparatus through a quantum channel, based two different measurement bases; verifying security of the quantum channel using verification qubit pairs in the transmission qubit pairs; and if the security has been verified, decoding measurement values of one qubit, in which a generation basis and a measurement basis are identical, in each transmission qubit pair into the shared key.
The method using the multi-user quantum key distribution apparatus and the quantum key client device may include generating, by the multi-user quantum key distribution apparatus, transmission qubit pairs based on a key bit string of a shared key to be distributed to the quantum key client device; measuring, by the quantum key client device, two respective qubits of each transmission qubit pair received from the multi-user quantum key distribution apparatus through a quantum channel in two different measurement bases; verifying security of the quantum channel using verification qubit pairs in the transmission qubit pair, and if the security is verified, decoding measurement values of one qubit, in which a generation basis is identical to a measurement basis, in each transmission qubit pair, into the shared key.
Generating the key qubit pairs may be configured to generate key qubit pairs, each including two identical key qubits for each key bit in the key bit string.
Generating the key qubit pairs may be configured to determine the two identical key qubits included in each key qubit pair based on both key values of the key bits and a generation basis corresponding to any one of a rectilinear basis and a diagonal basis.
Generating the key qubit pairs may be configured to determine an arrangement sequence of the generated key qubit pairs depending on an arrangement sequence of the key bits in the key bit string.
Generating the verification qubit pairs may be configured such that a number of transmission qubit pairs is greater than a number of key bits, and a number of verification qubit pairs to be generated is determined using a difference between the number of transmission qubit pairs and the number of key bits.
Generating the transmission qubit pairs based on the key qubit pairs and the verification qubit pairs may be configured to generate the transmission qubit pairs by arranging the verification qubit pairs at any one of arrangement locations respectively adjacent to the key qubit pairs and arrangement locations respectively adjacent to previously arranged verification qubit pairs.
Generating the transmission qubit pairs based on the key qubit pairs and the verification qubit pairs may be configured such that the multi-user quantum key distribution apparatus stores arrangement locations of the key qubit pairs and the verification qubit pairs arranged in each of the transmission qubit pairs.
Measuring the two qubits of each of the transmission qubit pairs may include receiving the generated transmission qubit pairs through the quantum channel; measuring the received transmission qubit pair in different measurement bases; and storing qubit measurement values of the transmission qubit pair.
Receiving the generated transmission qubit pairs may be configured such that the quantum key client device may receive arrangement locations and sequences of the key qubit pairs and the verification qubit pairs arranged in each of the transmission qubit pairs from the multi-user quantum key distribution apparatus.
Measuring the received transmission qubit pairs in different measurement bases may be configured such that the quantum key client device measures two qubits forming each transmission qubit pair by randomly selecting a sequence of the rectilinear measurement basis and the diagonal measurement basis.
Storing the qubit measurement values may be configured such that the quantum key client device stores the qubit measurement values that include both result values obtained by measuring each transmission qubit pair in the rectilinear basis and result values obtained by measuring each transmission qubit pair in the diagonal basis.
Verifying the security may be configured such that the multi-user quantum key distribution apparatus discloses states of verification qubits included in each transmission qubit pair, arrangement locations of the verification qubits, and a generation basis used to generate the verification qubits to the quantum key client device through a classical channel.
Verifying the security may be configured such that the quantum key client device determines, based on a comparison, whether measurement values in a measurement basis identical to the generation basis are identical to verification qubits, using the disclosed verification qubits, the arrangement locations of the disclosed verification qubits, and the generation basis of the disclosed verification qubits.
Verifying the security may be configured to, if it is determined that the qubit measurement results are identical to states of the verification qubits disclosed by the distribution apparatus, verify that the quantum channel is secure as a result of verification of security of the quantum channel.
Decoding the qubit measurement values may be configured such that, if it is verified that the quantum channel is secure as a result of verification of security of the quantum channel, the multi-user quantum key distribution apparatus discloses arrangement locations of key qubit pairs included in the transmission qubit pair and a generation basis used to generate the key qubit pairs to the quantum key client device through the classical channel.
Decoding the qubit measurement values may be configured such that, based on the disclosed arrangement locations of the key qubit pairs and the disclosed generation basis of the key qubit pairs, the quantum key client device decodes result values measured in a measurement basis identical to the generation basis into the key bit string of the shared key.
In accordance with another aspect of the present invention to accomplish the above objects, there is provided an apparatus for multi-user quantum key distribution, including a quantum random number generation unit for randomly generating a key bit string of a shared key to be distributed to quantum key client devices, based on quantum states; a qubit generation unit for generating transmission qubit pairs based on the key bit string; a qubit transmission unit for transmitting the transmission qubit pairs to the quantum key client device through a quantum channel; and a classical signal transmission/reception unit for disclosing information related to the transmission qubit pairs through a classical channel.
In accordance with a further aspect of the present invention to accomplish the above objects, there is provided a quantum key client device, including a qubit measurement unit for measuring transmission qubit pairs, received from a multi-user quantum key distribution apparatus through a quantum channel, based on a measurement basis; a quantum random number generation unit for selecting a sequence of measurement bases based on quantum states; a classical signal transmission/reception unit for receiving pieces of information related to the transmission qubit pairs through a classical channel; and a measurement result processing unit for determining, based on a comparison, whether the pieces of information related to the transmission qubit pairs are identical to qubit measurement values obtained by measuring the transmission qubit pairs, for verifying security of the quantum channel, and for decoding the qubit measurement values into a key bit string of a shared key to be distributed by the multi-user quantum key distribution apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a block diagram of an apparatus for multi-user quantum key distribution according to an embodiment of the present invention;
FIG. 2 is a table showing key qubit pairs according to an embodiment of the present invention;
FIGS. 3A and 3B are tables showing verification qubit pairs according to embodiments of the present invention;
FIG. 4 is a table showing transmission qubit pairs according to an embodiment of the present invention;
FIG. 5 is a diagram illustrating the distribution of the same key by the apparatus for multi-user quantum key distribution according to an embodiment of the present invention;
FIG. 6 is a graph showing a comparison in key distribution efficiency versus the number of users according to an embodiment of the present invention;
FIG. 7 is an operation flowchart illustrating a method for quantum key distribution according to an embodiment of the present invention;
FIG. 8 is an operation flowchart illustrating in detail an example of the transmission qubit pair generation step shown in FIG. 7 ;
FIG. 9 is an operation flowchart illustrating in detail an example of the transmission qubit pair measurement step shown in FIG. 7 ;
FIG. 10 is an operation flowchart illustrating in detail an example of the quantum channel security verification step shown in FIG. 7 ;
FIG. 11 is an operation flowchart illustrating in detail an example of the shared key decoding step shown in FIG. 7 ; and
FIG. 12 is a block diagram showing a computer system according to an embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described in detail below with reference to the accompanying drawings. Repeated descriptions and descriptions of known functions and configurations which have been deemed to make the gist of the present invention unnecessarily obscure will be omitted below. The embodiments of the present invention are intended to fully describe the present invention to a person having ordinary knowledge in the art to which the present invention pertains. Accordingly, the shapes, sizes, etc. of components in the drawings may be exaggerated to make the description clearer.
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.
FIG. 1 is a block diagram of an apparatus for multi-user quantum key distribution according to an embodiment of the present invention. FIG. 2 is a table showing key qubit pairs according to an embodiment of the present invention. FIGS. 3A and 3B are tables showing verification qubit pairs according to embodiments of the present invention. FIG. 4 is a table showing transmission qubit pairs according to an embodiment of the present invention. FIG. 5 is a diagram illustrating the distribution of the same key by the apparatus for multi-user quantum key distribution according to an embodiment of the present invention.
Referring to FIG. 1 , an apparatus 100 for multi-user quantum key distribution (hereinafter referred to as a âmulti-user quantum key distribution apparatus 100 â) and a quantum key client device 200 according to an embodiment of the present invention are illustrated.
The multi-user quantum key distribution apparatus 100 includes a quantum random number generation unit 104 , a qubit generation unit 106 , a qubit transmission unit 108 , a classical signal transmission/ reception unit 110 , and memory 120 .
The quantum random number generation unit 104 may generate a key bit string of a shared key to be distributed to the quantum key client device 200 based on quantum states.
Here, the quantum random number generation unit 104 may randomly generate a key bit string based on quantum properties.
The qubit generation unit 106 may generate transmission qubit pairs based on both the key bit string and the quantum random number generation unit 104 .
Here, the qubit generation unit 106 may generate key qubit pairs based on the key bit string of the shared key.
The qubit generation unit 106 may generate a pair of two identical key qubits (|Ï
k
1 , |Ï
k
1 ) for one bit. Here the subscript i is a sequence pair number. The generated key qubit pair may be separated into two types according to the generation basis. When the generation basis is a rectilinear basis, qubits capable of being generated may be |0
and |1
, and when the generation basis is a diagonal basis, qubits capable of being generated may be |+
and |â
.
That is, the qubit generation unit 106 may generate key qubit pairs, each including two identical key qubits for each key bit in the key bit string.
The qubit generation unit 106 may determine two identical key qubits included in each key qubit pair based on the key value of each key bit and the generation basis corresponding to any one of the rectilinear basis and the diagonal basis.
In order to share a key value of â0â in a key bit, the multi-user quantum key distribution apparatus 100 may prepare a key qubit pair of (|0
,|0
) or (|+
,|+
) and transmit the key qubit pair to the quantum key client device 200 . In order to share a key value of â1â in a key bit, the multi-user quantum key distribution apparatus 100 may prepare a key qubit pair of (| 1
,| 1
) or (|â
,|â
) and transmit the key qubit pair to the quantum key client device 200 .
Here, the qubit generation unit 106 may determine the sequence of arrangement of the generated key qubit pairs depending on the sequence of arrangement of key bits in the key bit string.
Further, the qubit generation unit 106 may generate verification qubit pairs.
In this case, the qubit generation unit 106 may be configured such that the number of transmission qubit pairs desired to be transmitted is greater than the number of key bits, and may determine the number of verification qubit pairs to be generated using the difference between the number of transmission qubit pairs and the number of key qubit pairs.
In this case, when the number of key qubit pairs that is desired to be shared is n and the number of transmission qubit pairs to be transmitted is N, as given in Equation (1), the relationship N>n may be satisfied. Here, the difference c between N and n may be the number of verification qubit pairs. Nân=c may be the number of verification qubit pairs used to verify the security of channels.
|Ï
k
1 ={|0
,|1
,|+
,|â
}, i= 1,2, . . . , n ââ(1)
Here, the qubit generation unit 106 may generate c verification qubit pairs.
(|Ï
d
2j-1 ,|Ï
d
2j )ââ(2)
In this case, as shown in Equation (2), |Ï
d
2j-1 or |Ï
d
2j â{|0
,|1
,|+
,|â
} satisfied.
That is, unlike the key qubit pair (|Ï
k
i ,|Ï
k
i ) in Equation (1), for two verification qubits forming each of c verification qubit pairs, each generated using 2c qubits, different states and different basis states may be possible. These may be given in the following Equation (3) and the following Table 1.
(|Ï
d
2j-1 ,|Ï
d
2j )â{(|0
,|1
),(|1
,|0
),(|+
,|â
),(|â
,|+
),(|0
,|+
),(|0
,|â
),(|1
,|+
),(|1
,|â
),(|+
,|0
),(|â
,|1
),(|â
,|0
),(|â
,|1
<img id="CUSTOM-CHARACTER-00055" he="3.56mm" wi="0.68mm" file="US10567169-20200218-P00001.TIF" alt="Figure US1056
CLAIMS
Claims ( 19 )
What is claimed is:
1. A method for multi-user quantum key distribution, the method being performed using a multi-user quantum key distribution apparatus and a plurality of quantum key client devices, the method comprising:
generating, by the multi-user quantum key distribution apparatus, transmission qubit pairs based on a key bit string of a shared key which is to be distributed to each of the quantum key client devices;
measuring, by each of the quantum key client devices, the transmission qubit pairs, received from the multi-user quantum key distribution apparatus through a quantum channel, based on a measurement basis;
verifying security of the quantum channel using verification qubit pairs of the transmission qubit pairs; and
if the security has been verified, decoding qubit measurement values of the transmission qubit pairs into the shared key,
wherein generating the transmission qubit pairs comprises:
generating key qubit pairs based on the key bit string of the shared key;
generating verification qubit pairs by selecting one or more of quantum states having non-orthogonality therebetween; and
generating the transmission qubit pairs based on the key qubit pairs and the verification qubit pairs.
2. The method of claim 1 , wherein generating the key qubit pairs is configured to generate key qubit pairs, each including two identical key qubits for each key bit in the key bit string.
3. The method of claim 2 , wherein generating the key qubit pairs is configured to determine the two identical key qubits included in each key qubit pair based on both key values of the key bits and a generation basis corresponding to any one of a rectilinear basis and a diagonal basis.
4. The method of claim 3 , wherein generating the key qubit pairs is configured to determine an arrangement sequence of the generated key qubit pairs depending on an arrangement sequence of the key bits in the key bit string.
5. The method of claim 4 , wherein generating the verification qubit pairs is configured such that:
a number of transmission qubit pairs is greater than a number of key bits, and
a number of verification qubit pairs to be generated is determined using a difference between the number of transmission qubit pairs and the length of a shared key.
6. The method of claim 5 , wherein generating the transmission qubit pairs based on the key qubit pairs and the verification qubit pairs is configured to generate the transmission qubit pairs by arranging the verification qubit pairs at any one of arrangement locations respectively adjacent to the key qubit pairs and arrangement locations respectively adjacent to previously arranged verification qubit pairs.
7. The method of claim 6 , wherein generating the transmission qubit pairs based on the key qubit pairs and the verification qubit pairs is configured such that the multi-user quantum key distribution apparatus stores arrangement locations of the key qubit pairs and the verification qubit pairs arranged in each of the transmission qubit pairs.
8. The method of claim 7 , wherein measuring the transmission qubit pairs comprises:
receiving the generated transmission qubit pairs through the quantum channel;
measuring two qubits forming each of the received transmission qubit pairs in different measurement bases; and
storing qubit measurement values of each of the transmission qubit pairs.
9. The method of claim 8 , wherein receiving the generated transmission qubit pairs is configured such that the quantum key client device receives key qubit pairs and verification qubit pairs arranged in each of the transmission qubit pairs from the multi-user quantum key distribution apparatus in a sequence of arrangement of the key qubit pairs and the verification qubit pairs.
10. The method of claim 9 , wherein measuring the two qubits forming each of the received transmission qubit pairs in different measurement bases is configured such that the quantum key client device measures each of the qubits of the received transmission qubit pair by using the rectilinear basis and the diagonal basis for each of the qubits of the transmission qubit pair.
11. The method of claim 10 , wherein measuring the two qubits forming each of the received transmission qubit pairs in different measurement bases is configured to respectively measure the qubits of the received transmission qubit pair in any one of a sequence of the rectilinear basis-diagonal basis and a sequence of the diagonal basis-rectilinear basis by using the rectilinear basis and the diagonal basis.
12. The method of claim 11 , wherein storing the qubit measurement values is configured such that the quantum key client device stores the qubit measurement values that include both result values obtained by measuring each transmission qubit pair in the rectilinear basis and result values obtained by measuring each transmission qubit pair in the diagonal basis.
13. The method of claim 12 , wherein verifying the security is configured such that the multi-user quantum key distribution apparatus discloses at least one of arrangement locations of the verification qubits and a generation basis used to generate the verification qubits to the quantum key client device through a classical channel.
14. The method of claim 13 , wherein verifying the security is configured such that the quantum key client device determines, based on a comparison, whether the measurement results, which are measured based on at least one of the disclosed the states of verification qubits, the arrangement locations of the disclosed verification qubits, and the generation basis of the disclosed verification qubits, are identical to values measured in a basis identical to a generation basis of the verification qubits, among qubit measurement values stored in the quantum key client device.
15. The method of claim 14 , wherein verifying the security is configured to, if it is determined that the measurement results are identical to the measurement values, verify that the quantum channel is secure as a result of verification of security of the quantum channel.
16. The method of claim 15 , wherein decoding the qubit measurement values is configured such that, if it is verified that the quantum channel is secure as a result of verification of security of the quantum channel, the multi-user quantum key distribution apparatus discloses at least one of arrangement locations of key qubit pairs included in the transmission qubit pair and a generation basis used to generate the key qubit pairs to the quantum key client device through the classical channel.
17. The method of claim 16 , wherein decoding the qubit measurement values is configured such that, based on the disclosed arrangement locations of the key qubit pairs and the disclosed generation basis of the key qubit pairs, the quantum key client device decodes measurement result values in a measurement basis identical to the generation basis into the key bit string of the shared key.
18. An apparatus for multi-user quantum key distribution, comprising:
at least one processor;
a memory having instructions stored thereon, which, when executed by the at least one processor, cause the at least on processor to function as:
a quantum random number generation unit configured to generate a key bit string of a shared key to be distributed to each of a plurality of quantum key client devices, based on quantum states;
a qubit generation unit configured to generate key qubit pairs based on the key bit string of the shared key, to generate verification qubit pairs by selecting one or more of quantum states having non-orthogonality therebetween, and to generate transmission qubit pairs based on the key qubit pairs and the verification qubit pairs;
a qubit transmission unit configured to transmit the transmission qubit pairs to each of the quantum key client devices through a quantum channel; and
a classical signal transmission/reception unit configured to disclose information related to the transmission qubit pairs through a classical channel.
19. A quantum key client device comprising:
at least one processor;
a memory having instructions stored thereon, which, when executed by the at least one processor, cause the at least on processor to function as:
a qubit measurement unit configured to measure transmission qubit pairs, received from a multi-user quantum key distribution apparatus through a quantum channel, based on a measurement basis;
a quantum random number generation unit configured to select a sequence of the measurement bases based on quantum states;
a classical signal transmission/reception unit configured to receive pieces of information related to the transmission qubit pairs through a classical channel; and
a measurement result processing unit configured to determine, based on a comparison, whether the pieces of information related to the transmission qubit pairs are identical to qubit measurement values obtained by measuring the transmission qubit pairs, to verify security of the quantum channel, and to decode the qubit measurement values into a key bit string of a shared key to be distributed by the multi-user quantum key distribution apparatus.
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Cited By (4)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US11245584B2
( en )
*
2018-10-15
2022-02-08
Red Hat, Inc.
Software defined network optimization using quantum computing
US11770245B2
( en )
2020-11-04
2023-09-26
Electronics And Telecommunications Research Institute
Quantum key distribution system and operation method thereof
US12450509B2
( en )
2021-02-24
2025-10-21
Red Hat, Inc.
Access protection for shared qubits
US12519624B2
( en )
2023-01-25
2026-01-06
Nokia Technologies Oy
Identity authentication for QKD protocols
Families Citing this family (28)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
SG11201803545QA
( en )
*
2015-10-29
2018-05-30
Google Llc
Removing leakage in a quantum bit
US11343087B1
( en )
2018-03-09
2022-05-24
Wells Fargo Bank, N.A.
Systems and methods for server-side quantum session authentication
US10855454B1
( en )
2018-03-09
2020-12-01
Wells Fargo Bank, N.A.
Systems and methods for quantum session authentication
US11025416B1
( en )
*
2018-03-09
2021-06-01
Wells Fargo Bank, N.A.
Systems and methods for quantum session authentication
US10812258B1
( en )
*
2018-03-09
2020-10-20
Wells Fargo Bank, N.A.
Systems and methods for quantum session authentication
US10728029B1
( en )
*
2018-03-09
2020-07-28
Wells Fargo Bank, N.A.
Systems and methods for multi-server quantum session authentication
CN108964890B
( en )
*
2018-06-15
2021-06-04
å京åçå½ç¾éåææ¯æéå ¬å¸
Authenticable multi-party quantum key distribution method based on tree type hierarchical structure
US10855453B1
( en )
2018-08-20
2020-12-01
Wells Fargo Bank, N.A.
Systems and methods for time-bin quantum session authentication
US10855457B1
( en )
*
2018-08-20
2020-12-01
Wells Fargo Bank, N.A.
Systems and methods for single chip quantum random number generation
US10540146B1
( en )
2018-08-20
2020-01-21
Wells Fargo Bank, N.A.
Systems and methods for single chip quantum random number generation
US11240013B1
( en )
*
2018-08-20
2022-02-01
Wells Fargo Bank, N.A.
Systems and methods for passive quantum session authentication
US11095439B1
( en )
2018-08-20
2021-08-17
Wells Fargo Bank, N.A.
Systems and methods for centralized quantum session authentication
US11190349B1
( en )
*
2018-08-20
2021-11-30
Wells Fargo Bank, N.A.
Systems and methods for providing randomness-as-a-service
US10552120B1
( en )
2018-08-20
2020-02-04
Wells Fargo Bank, N.A.
Systems and methods for single chip quantum random number generation
CN108988956B
( en )
*
2018-09-19
2021-06-18
èå·å¤§å¦
A three-party communication method based on seven-bit quantum channel
KR102148861B1
( en )
*
2018-11-05
2020-10-14
íêµê³¼í기ì ì°êµ¬ì
Method for authenticating using authentication qubit and quantum communication system thereof
CN109660340B
( en )
*
2018-12-11
2021-11-26
å京å®å¾¡éåç§ææéå ¬å¸
Application system based on quantum key and use method thereof
KR102063031B1
( en )
2019-03-27
2020-01-07
íêµì ìíµì ì°êµ¬ì
Apparatus and method for quantum direct communication using single qubits
CN110138550B
( en )
*
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2022-09-30
å½ç½çèççµåå ¬å¸ä¿¡æ¯éä¿¡å ¬å¸
QKD network system model construction method
US11245519B1
( en )
2019-10-04
2022-02-08
Wells Fargo Bank, N.A.
Systems and methods for quantum entanglement random number generation
JP7282713B2
( en )
*
2020-04-16
2023-05-29
æ ªå¼ä¼ç¤¾æ±è
Quantum Cryptography Device, Quantum Cryptography Communication Charge Calculation System, and Quantum Cryptography Communication Charge Calculation Method
US20230353350A1
( en )
*
2020-05-12
2023-11-02
Eth Zurich
Device-independent quantum key distribution
KR20240021193A
( en )
*
2021-05-31
2024-02-16
íìì¨ì´ í í¬ëë¡ì§ì¤ ìºëë¤ ì»´í¼ë, 리미í°ë
Method and system for two-qubit multi-user quantum key distribution protocol
CN114338013B
( en )
*
2021-12-31
2023-12-22
å½å®¶çµç½æéå ¬å¸ä¿¡æ¯éä¿¡åå ¬å¸
A dynamic power control method and device for co-fiber transmission of quantum signals and classical signals
WO2024015105A1
( en )
*
2022-07-15
2024-01-18
Matrics2, Inc.
Delivering random number keys securely for one-time pad symmetric key encryption
US12476984B2
( en )
*
2023-08-15
2025-11-18
Wells Fargo Bank, N.A.
Quantum-based information protection
US20250317281A1
( en )
*
2024-04-09
2025-10-09
Mellanox Technologies, Ltd.
System for implementing quantum key distribution (qkd) in a data center environment
US20260106738A1
( en )
*
2024-10-15
2026-04-16
Bank Of America Corporation
System and method for establishing a secure quantum key distribution communications protocol based on quantum entanglement
Citations (7)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
KR20040058326A
( en )
2002-09-26
2004-07-03
미ì°ë¹ìë´í¤ ê°ë¶ìí¤ê°ì´ì¤
Cryptographic communication apparatus
KR100596404B1
( en )
2004-04-13
2006-07-03
íêµì ìíµì ì°êµ¬ì
Quantum key distribution method between multiparty or multigroup
KR20120071883A
( en )
2010-12-23
2012-07-03
íêµì ìíµì ì°êµ¬ì
Quantum authentication method and apparatus for quantum secret sharing protocol
KR101351012B1
( en )
2009-12-18
2014-01-10
íêµì ìíµì ì°êµ¬ì
Method and apparatus for authentication user in multiparty quantum communications
KR20140054647A
( en )
2012-10-29
2014-05-09
ìì¤ì¼ì´í ë 콤 주ìíì¬
Method for enhancing security of secret key generated in quantum key distribution system
KR20140060022A
( en )
2012-11-09
2014-05-19
íêµì ìíµì ì°êµ¬ì
Quantum signature method using arbitrator and system using it
US8885828B2
( en )
2008-01-25
2014-11-11
Qinetiq Limited
Multi-community network with quantum key distribution
2016
2016-09-06
KR
KR1020160114646A
patent/KR101960426B1/en
active
Active
2017
2017-02-16
US
US15/434,188
patent/US10567169B2/en
active
Active
Patent Citations (11)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
KR20040058326A
( en )
2002-09-26
2004-07-03
미ì°ë¹ìë´í¤ ê°ë¶ìí¤ê°ì´ì¤
Cryptographic communication apparatus
US20050157875A1
( en )
*
2002-09-26
2005-07-21
Tsuyoshi Nishioka
Crytographic communication apparatus
US7649996B2
( en )
2002-09-26
2010-01-19
Mitsubishi Denki Kabushiki Kaisha
Cryptographic communication apparatus
KR100596404B1
( en )
2004-04-13
2006-07-03
íêµì ìíµì ì°êµ¬ì
Quantum key distribution method between multiparty or multigroup
US7496203B2
( en )
2004-04-13
2009-02-24
Electronics And Telecommunications Research Institute
Quantum-key distribution method between a plurality of users or groups
US8885828B2
( en )
2008-01-25
2014-11-11
Qinetiq Limited
Multi-community network with quantum key distribution
KR101351012B1
( en )
2009-12-18
2014-01-10
íêµì ìíµì ì°êµ¬ì
Method and apparatus for authentication user in multiparty quantum communications
US20140068765A1
( en )
2009-12-18
2014-03-06
Electronics And Telecommunications Research Institute
Method and apparatus for authenticating user in multiparty quantum communications
KR20120071883A
( en )
2010-12-23
2012-07-03
íêµì ìíµì ì°êµ¬ì
Quantum authentication method and apparatus for quantum secret sharing protocol
KR20140054647A
( en )
2012-10-29
2014-05-09
ìì¤ì¼ì´í ë 콤 주ìíì¬
Method for enhancing security of secret key generated in quantum key distribution system
KR20140060022A
( en )
2012-11-09
2014-05-19
íêµì ìíµì ì°êµ¬ì
Quantum signature method using arbitrator and system using it
Cited By (4)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US11245584B2
( en )
*
2018-10-15
2022-02-08
Red Hat, Inc.
Software defined network optimization using quantum computing
US11770245B2
( en )
2020-11-04
2023-09-26
Electronics And Telecommunications Research Institute
Quantum key distribution system and operation method thereof
US12450509B2
( en )
2021-02-24
2025-10-21
Red Hat, Inc.
Access protection for shared qubits
US12519624B2
( en )
2023-01-25
2026-01-06
Nokia Technologies Oy
Identity authentication for QKD protocols
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