A quantum encryption method and device and a quantum communication method

Abstract

The application discloses a quantum encryption method and device and a quantum communication method, which utilize a set quantum computing circuit to change the state of input bits, and thus the encryption of the input bits is achieved in a smart and simple way. In this way, in quantum communication, encrypted information of encrypted bits to be encrypted is transmitted, and the security and confidentiality of the transmitted information are further improved. Moreover, the quantum encryption method provided by the embodiment of the application can simply realize the quantum encryption operation on a classical computer.

Description

Technical Field

[0001] This application relates to, but is not limited to, quantum technology, and in particular to a quantum encryption method and device and a quantum communication method. Background Technology

[0002] In classic computers, all data storage and operations require the use of binary numbers, including uppercase and lowercase letters such as a, b, c, d, digits such as 0 and 1, and commonly used symbols such as *, #, and @. To facilitate common compilation and communication, standardization organizations use ASCII encoding to uniformly define the binary numbers corresponding to these commonly used symbols. The International Organization for Standardization (ISO) developed the ISO 646 standard, applicable to all Latin alphabets.

[0003] To ensure the security of information transmission, people encrypt the information to be transmitted in order to hide the meaning of the transmitted information. Summary of the Invention

[0004] This application provides a quantum encryption method and device, as well as a quantum communication method, which can implement simple quantum encryption operations on a classical computer, further improving the security and confidentiality of encrypted content.

[0005] This invention provides a quantum encryption method, including: pre-setting a quantum computing circuit;

[0006] The bits to be encrypted are input into a quantum computing circuit, causing the input bits to undergo ecological changes, thus obtaining encrypted information composed of quantum states.

[0007] In one exemplary instance, it also includes:

[0008] The partial information in the information processed by the quantum computing circuit is subjected to at least one reduction to obtain a partial trace, wherein the partial information in each reduction partial trace is not repeated, and at least one result of the reduction partial trace is used as the encrypted information after encrypting the bit to be encrypted.

[0009] In one exemplary instance, the bits to be encrypted are N qubits; the information processed by the quantum computing circuit consists of the quantum states corresponding to the N bits. N 3D density matrix;

[0010] The multiple reduction bias tracings include two types of reduction bias tracings; multiple reduction bias tracings are performed on a portion of the information after processing by the quantum computing circuit, including:

[0011] After processing the quantum computing circuit, the (Nx) qubits in the resulting N qubit states are reduced and the bias trace is calculated to obtain 2. x The reduced density matrix, this 2x The reduced density matrix is ​​the first encrypted information; and

[0012] After processing the quantum computing circuit, x qubits in the N qubit states are reduced and the bias path is calculated to obtain 2. (N-x) The reduced density matrix, this 2 (N-x) The reduced density matrix is ​​the second encrypted information;

[0013] Where x is any value from 1 to (N-1).

[0014] In one exemplary instance, it also includes:

[0015] At least two quantum states in the information processed by the quantum computing circuit are subjected to quantum Fourier transform to obtain third and fourth encrypted information; the third and fourth encrypted information are used as the bits to be encrypted to encrypt the encrypted information.

[0016] In one exemplary instance, the bits to be encrypted are N qubits; the information processed by the quantum computing circuit consists of the quantum states corresponding to the N bits. N 3D density matrix;

[0017] The process of performing a quantum Fourier transform on at least two qubit states in the information processed by the quantum computing circuit to obtain third and fourth encrypted information includes:

[0018] Performing a quantum Fourier transform on the y qubit states processed by the quantum computing circuit yields the 2 qubit states corresponding to the full set of qubit states. N The real density matrix and 2 N The imaginary part density matrix is ​​given by , where y is any value from 2 to N; this 2 N The 2-dimensional real density matrix is ​​the third encrypted information. N The imaginary part density matrix represents the fourth encrypted information.

[0019] In one exemplary instance, it also includes:

[0020] The partial information obtained from the quantum Fourier transform is subjected to at least one reduction to obtain a partial trace, wherein the partial information in each reduction partial trace is not repeated, and at least one result of the reduction partial trace is used as the encrypted information after encrypting the bit to be encrypted.

[0021] In one exemplary instance, the bits to be encrypted are N bits; the information processed by the quantum computing circuit consists of the quantum states corresponding to the N bits. N 3D density matrix;

[0022] The process of performing a quantum Fourier transform on at least two qubit states in the information processed by the quantum computing circuit includes:

[0023] Performing a quantum Fourier transform on the y qubit states processed by the quantum computing circuit yields the 2 qubit states corresponding to the full set of qubit states. N The real density matrix and 2 N The imaginary part density matrix; where y is any value from 2 to N;

[0024] The multiple reduction partial trajectories include two types of reduction partial trajectories; the process of performing at least one reduction partial trajectories on a portion of the information obtained from the quantum Fourier transform includes:

[0025] The reduction and partial trace of (Nz) qubits in the N qubit states obtained after the quantum Fourier transform are obtained by the following method: z Reduced real part density matrix and 2 z The reduced imaginary density matrix; this 2 z The reduced real density matrix is ​​the fifth encrypted information, which is 2 z The reduced imaginary part density matrix is ​​the sixth encrypted information;

[0026] The z qubits of the N qubit states obtained after the quantum Fourier transform are reduced and the partial trace is obtained by taking the reduction of z qubits. (N-z) Reduced real part density matrix and 2 (N-z) The reduced imaginary density matrix; this 2 (N-z) The reduced real density matrix is ​​the seventh encrypted information, which is 2 (N-z) The reduced imaginary part density matrix is ​​the eighth encrypted information;

[0027] Where z is any value from 1 to (N-1).

[0028] In one exemplary instance, it also includes:

[0029] Based on the size of the matrix elements of the density matrix corresponding to the encrypted information after encryption of the bits to be encrypted, a color chart reflecting the encrypted information is drawn.

[0030] This application also provides a quantum communication method, including:

[0031] The sender encrypts the bit to be encrypted according to any of the quantum encryption methods described in claims 1 to 9 to obtain encrypted information; and transmits the obtained encrypted information to at least one receiver.

[0032] This application further provides a quantum communication method, including:

[0033] Upon receiving the encrypted information, the receiver processes the received encrypted information according to the reverse process corresponding to any of the quantum encryption methods described in claims 1 to 9 to restore the bits to be encrypted.

[0034] The quantum encryption method provided in this application cleverly and simply encrypts the input bits by using a pre-configured quantum computing circuit to cause ecological changes in the input bits. Thus, in quantum communication, by transmitting encrypted information after encrypting the bits to be encrypted, the security and confidentiality of transmitted information are further improved. Moreover, the quantum encryption method provided in this application allows for the simple implementation of quantum encryption operations on a classical computer.

[0035] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0036] The accompanying drawings are used to provide a further understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0037] Figure 1 This is a flowchart illustrating an embodiment of the quantum encryption method in this application.

[0038] Figure 2 This is a schematic diagram of the first embodiment of the quantum encryption method in this application;

[0039] Figure 3 This is a schematic diagram of the second embodiment of the quantum encryption method in this application.

[0040] Figure 4 This is a schematic diagram of the third embodiment of the quantum encryption method in this application;

[0041] Figure 5 This is a schematic diagram of the fourth embodiment of the quantum encryption method in this application;

[0042] Figure 6 This is a schematic diagram of the fifth embodiment of the quantum encryption method in this application;

[0043] Figure 7 This is a schematic diagram of the sixth embodiment of the quantum encryption method in this application;

[0044] Figure 8 This is a schematic diagram of the color chart of quantum encryption information in the embodiments of this application;

[0045] Figure 9 This is a schematic diagram of the composition and structure of the quantum encryption device in the embodiments of this application. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be arbitrarily combined with each other.

[0047] Figure 1 This is a flowchart illustrating an embodiment of the quantum encryption method in this application. Figure 1 As shown, it includes:

[0048] Step 100: Pre-configure the quantum computing circuitry.

[0049] In this embodiment, a quantum computing circuit, also known as a quantum logic circuit, is used to represent a circuit that operates on qubits in an abstract concept. A quantum computing circuit can be composed of various quantum logic gates. There are no requirements for the design of the quantum computing circuit, as long as it allows the input bits to undergo dynamic changes.

[0050] In one exemplary instance, the quantum computing circuitry can be configured according to the actual application scenario. For example, more complex quantum computing circuitry can be configured for scenarios with higher security requirements, while simpler quantum computing circuitry can be configured for scenarios with lower security requirements.

[0051] Step 101: Input the bit to be encrypted into the quantum computing circuit, causing the input bit to undergo ecological changes, and obtain encrypted information composed of quantum states.

[0052] In one exemplary instance, the bits to be encrypted may include classical bits, or they may be quantum bits, photonic bits, etc.

[0053] In one exemplary instance, such as Figure 2 As shown, assuming there are N bits to be encrypted, after processing by a quantum computing circuit, a quantum state consisting of the N bits is obtained. N 2D density matrix, that is, 2 N The density matrix represents the encrypted information after encrypting the bit to be encrypted. In this embodiment, the bit to be encrypted, after passing through the quantum computing circuit provided in this application embodiment, obtains a 2D quantum state corresponding to all quantum positions. N 2D density matrix, this 2 N The density matrix is ​​used as the encrypted information after encrypting the bits to be encrypted.

[0054] In one exemplary instance, the value of N bits depends on the type of data to be encrypted, which can include, but is not limited to, qubits with a doublet state, such as superconducting qubits and photonic qubits. The upper limit for the types of information that can be encrypted is 2. N The number of types. The value of N directly determines the number of binary numbers that can be encrypted. In other words, the value of N depends on the size of the number to be encrypted. A reasonable choice is within the range of 2... N Within a certain size range, simply avoid wasting resources.

[0055] In this embodiment, the quantum computing circuit is equivalent to the encryption rules agreed upon in advance by the two communicating parties. The sender of the information calculates the bit to be encrypted according to the quantum computing circuit, and transmits the encrypted information, which is composed of the quantum state after the change of the generated state, as the bit to be encrypted, to the receiver of the information. The receiver of the information then uses the inverse of the quantum computing circuit to process the received encrypted information and restore the bit to be encrypted, thereby achieving secure quantum communication.

[0056] The quantum encryption method provided in this application cleverly and simply encrypts the input bits by using a pre-configured quantum computing circuit to cause ecological changes in the input bits. Thus, in quantum communication, by transmitting encrypted information after encrypting the bits to be encrypted, the security and confidentiality of transmitted information are further improved. Moreover, the quantum encryption method provided in this application allows for the simple implementation of quantum encryption operations on a classical computer.

[0057] In one exemplary instance, to further enhance the security of quantum encryption and ensure the confidentiality of subsequent quantum communication, the quantum encryption method of this application embodiment may further include:

[0058] The partial information in the information processed by the quantum computing circuit is subjected to at least one reduction to obtain a partial trace, wherein the partial information in each reduction partial trace is unique. At least one result of the reduction partial trace is used as the encrypted information after encrypting the bit to be encrypted. It should be noted that the partial information refers to any part of the information in the information processed by the quantum computing circuit.

[0059] In one exemplary instance, assuming the bits to be encrypted are N bits, after processing by a quantum computing circuit, the information obtained is the quantum state structure corresponding to the N bits. N 2D density matrix; various reductions are applied to the N qubit states obtained after processing the quantum computing circuit to find the bias trace: one method is to reduce the (N-x1) qubits in the N qubit states obtained after processing the quantum computing circuit to find the bias trace, resulting in a 2D density matrix. x1 The reduced density matrix, this 2x1 The reduced density matrix is ​​one of the encrypted messages; the second method is to reduce (N-x2) qubits in the N qubit states obtained after processing the quantum computing circuit and find the bias trace to obtain 2. x2 The reduced density matrix, this 2 x2 The reduced density matrix is ​​one of the encrypted messages; ...; the m-th method is to reduce (N-xm) qubits in the N qubit states obtained after processing the quantum computing circuit and find the bias trace to obtain 2. xm The reduced density matrix, this 2 x2 The reduced density matrix is ​​one of the encrypted messages, ..., the m-th one is obtained by reducing (N-xm) qubits in the N qubit states obtained after processing the quantum computing circuit and taking the bias trace to get 2. xm The reduced density matrix, this 2 xm The reduced density matrix represents the m-th encrypted information. It is sufficient that the combined results of multiple reduced partial traces (e.g., m) contain all the input state information. Here, x1, x2…xm can be any value from 1 to (N-1), and the included qubits must be unique. For example, consider the 5 qubit states obtained after processing a quantum computing circuit, assuming they are a, b, c, d, and e. Then, we can reduce (5-2) qubits to find the bias trace, with 2 qubits including a and b; reduce (5-2) qubits to find the bias trace, with 2 qubits including c and d; reduce (5-2) qubits to find the bias trace, with 2 qubits including a and c; reduce (5-3) qubits to find the bias trace, with 3 qubits including c, d, and e; reduce (5-3) qubits to find the bias trace, with 3 qubits including a, b, and e; reduce (5-4) qubits to find the bias trace, with 4 qubits including a, c, d, and e; reduce (5-1) qubits to find the bias trace, with 1 qubit including e; ...

[0060] like Figure 3 As shown, taking the two reduction methods for finding the bias trace of N qubit states obtained after processing the quantum computing circuit as an example, one method is to reduce (Nx) qubits in the N qubit states obtained after processing the quantum computing circuit to obtain 2 x The reduced density matrix, this 2 x The reduced density matrix is ​​the first encrypted information; another method is to reduce x qubits in the N qubit states obtained after processing the quantum computing circuit and calculate the bias trace to obtain 2. (N-x) The reduced density matrix, this 2 (N-x) The reduced density matrix is ​​the second encrypted information. Here, x is any value from 1 to (N-1).

[0061] In this embodiment, 2 xThe reduced density matrix is ​​the density matrix of the quantum states of the remaining x qubits, constructed with information containing (Nx) bits. (N The -x)-dimensional reduced density matrix is ​​the density matrix of the quantum states of the remaining (Nx) qubits, constructed with x bits of information. In this embodiment, 2 x Dimensionally reduced density matrix or 2 (N-x) The reduced density matrix contains part of the input state information. At the receiver, it is only necessary to convert 2... x The reduced density matrix and 2 (N -x) After the reduced density matrices are merged, the unique input state, i.e. the bit to be encrypted, can be conveniently and securely restored together. This also realizes the confidentiality of the unique bit to be encrypted by using two quantum keys, further improving the confidentiality and security of quantum communication.

[0062] In this embodiment, the first encrypted information and the second encrypted information can be transmitted to different recipients. Only after the two encrypted information are combined can the bits to be encrypted be restored through the inverse quantum computing circuit, which further improves the security and confidentiality of the transmitted information.

[0063] In one exemplary instance, such as Figure 4 As shown, to further enhance the security of quantum encryption and ensure the confidentiality of subsequent quantum communication, the quantum encryption method in this application embodiment may further include:

[0064] Perform a quantum Fourier transform on at least two qubit states in the information processed by the quantum computing circuit to obtain the third and fourth encrypted information; use the third and fourth encrypted information as the bits to be encrypted to encrypt the encrypted information.

[0065] It should be noted that the purpose of the quantum Fourier transform is to manipulate some qubit states in a quantum circuit to obtain another series of density matrices. This application only uses the quantum Fourier transform as an example for description; however, it does not limit the scope of protection of this application. Other reversible unitary operations on quantum states or reordering of the state density matrix can also be used in this application to improve the encryption level.

[0066] In one exemplary instance, assuming the bits to be encrypted are N bits, after processing by a quantum computing circuit, the information obtained is the quantum state structure corresponding to the N bits. N A 2D density matrix; performing a quantum Fourier transform on the y qubit states after processing by the quantum computing circuit yields the 2D density matrix corresponding to the full qubit state. N The real density matrix and 2 NThe imaginary part density matrix is ​​given by , where y is any value from 2 to N. N The 2-dimensional real density matrix is ​​the third encrypted information. N The imaginary part density matrix represents the fourth encrypted information. Through quantum Fourier transform processing in this embodiment, a phase estimate is made, yielding the imaginary part and improving security.

[0067] In this embodiment, the third and fourth encrypted information can be transmitted to different recipients. Only after the two encrypted information are combined can the bits to be encrypted be restored through the inverse quantum computing circuit, which further improves the security and confidentiality of the transmitted information.

[0068] In one exemplary instance, to further enhance the security of quantum encryption and ensure the confidentiality of subsequent quantum communication, the quantum encryption method of this application embodiment may further include:

[0069] The partial information obtained from the quantum Fourier transform is subjected to at least one reduction to obtain a partial trace, wherein the partial information in each reduction partial trace is unique. At least one result of the reduction partial trace is used as the encrypted information after encrypting the bit to be encrypted. It should be noted that "partial information" refers to any portion of the information obtained after the Fourier transform.

[0070] In one exemplary instance, assuming the bits to be encrypted are N bits, after processing by a quantum computing circuit, the information obtained is the quantum state structure corresponding to the N qubits. N A 2D density matrix; performing a quantum Fourier transform on the y qubit states after processing by the quantum computing circuit yields the 2D density matrix corresponding to the full qubit state. N The real density matrix and 2 N The imaginary part density matrix is ​​given by , where y is any value from 2 to N; various reductions are performed on the N qubit states obtained after the quantum Fourier transform to find the bias trace: one method is to reduce the (N-z1) qubits of the N qubit states obtained after the quantum Fourier transform to obtain the 2 z1 Reduced real part density matrix and 2 z1 The reduced imaginary density matrix, this 2 z1 The reduced real density matrix and the 2 z1 The first method involves reducing the imaginary part density matrix to one of the encrypted information; the second method involves reducing (N-z²) qubits out of the N qubit states obtained after the quantum Fourier transform and calculating the bias trace to obtain 2. z2 Reduced real part density matrix and 2 z2 The reduced imaginary density matrix, this 2 z2 The reduced real density matrix and the 2 z2The reduced imaginary density matrix is ​​one of the encrypted messages; ...; the nth method is to reduce (N-zn) qubits in the N qubit states obtained after the quantum Fourier transform and find the bias trace to obtain 2 zn Reduced real part density matrix and 2 zn The reduced imaginary density matrix, this 2 zn The reduced real density matrix and the 2 zn The reduced imaginary part density matrix is ​​one of the encrypted information. It is sufficient that the combined results of multiple (e.g., n) reduced partial traces contain all the input state information. Here, z1, z2…zn are any values ​​from 1 to (N-1) and the included qubits are not repeated.

[0071] Taking the partial information obtained from the quantum Fourier transform and the partial information as an example, two reductions are applied to find the partial trace, including: one is, such as Figure 5 As shown, reducing (Nz) qubits in the N qubit states obtained after the quantum Fourier transform and finding the partial trace yields 2. z Reduced real part density matrix and 2 z The reduced imaginary part density matrix, where z is any value from 1 to (N-1), is 2. z The reduced real density matrix is ​​the fifth encrypted information, which is 2 z The reduced imaginary part density matrix is ​​the sixth encrypted information. Wherein, 2 z Reduced real part density matrix and 2 z The reduced imaginary density matrix is ​​the real and imaginary density matrix of the quantum state of the remaining z qubits, constructed with information containing (Nz) bits. Another approach is, as... Figure 6 As shown, reducing z qubits out of the N qubit states obtained after the quantum Fourier transform and finding the partial trace yields 2. (N-z) Reduced real part density matrix and 2 (N-z) The reduced imaginary part density matrix, where z is any value from 1 to (N-1), is 2. (N-z) The reduced real density matrix is ​​the seventh encrypted information, which is 2 (N-z) The reduced imaginary part density matrix is ​​the eighth encrypted information. Where, 2 (N-z) Reduced real part density matrix and 2 (N-z) The reduced imaginary density matrix is ​​the real and imaginary density matrix of the quantum state of the remaining (Nz) qubits, constructed under the premise of containing z bits of information.

[0072] In this embodiment, the fifth, sixth, seventh, and eighth encrypted information can be transmitted to different recipients. Only after the four encrypted information are combined can the bits to be encrypted be restored through the inverse quantum computing circuit, further improving the security and confidentiality of the transmitted information.

[0073] The density matrix in this application embodiment is derived from the quantum states of N bits input into the designed quantum computing circuit for computation, including but not limited to the quantum states measured during computation in the set quantum computing circuit, or the quantum states measured at the end of the set encryption method.

[0074] In one exemplary instance, in order to visually represent encrypted information on a classical computer, the quantum encryption method of this application may further include:

[0075] Based on the size of the matrix elements of the density matrix corresponding to the encrypted information obtained as the bits to be encrypted, a color chart reflecting the encrypted information is drawn.

[0076] In one embodiment, the color chart is drawn based on the size of the matrix elements of the density matrix. Different density matrices in this application can yield corresponding color charts, which are obtained using several different keys after input-state encryption. In one embodiment, the color chart includes, but is not limited to, all visualization methods utilizing the characteristics of the density matrix, such as two-dimensional planar diagrams and three-dimensional solid diagrams.

[0077] In one exemplary instance, the multiple density matrices containing partial information are combined to correspond to the confidentiality of unique encrypted content.

[0078] The quantum encryption method provided in this application embodiment utilizes 7 (2) 7 =128) or 8 (2 8 =256) The combination of qubits can compile the entire set of ASCII codes in related technologies. Therefore, the quantum encryption method provided in this application is simple. In one embodiment, the bit to be encrypted is processed in a pre-set quantum computing circuit. Then, the bit undergoes various forms of density matrix measurement calculations and visualization operations. The generation, pairing and encryption process of quantum keys can be easily realized on a classical computer, thereby applying the quantum encryption method to a classical computer to realize quantum communication.

[0079] In any of the above embodiments of this application, the density matrix contains some or all of the input state information. When multiple density matrices containing partial input state information are combined by the receiver, the unique input state, i.e. the information to be encrypted, can be conveniently and securely restored. This also achieves the confidentiality of several quantum keys corresponding to the unique information to be encrypted, further enhancing the confidentiality and security of quantum communication.

[0080] Figure 7 This is a schematic diagram of the sixth embodiment of the quantum encryption method in this application, as shown below. Figure 7 As shown, the dashed boxes represent potential processing steps. In this embodiment, a 5-qubit quantum computing circuit is used as an example. The computing circuit is composed of controlled NOT gates (CNOT gates) and Hadamard gates (H gates). It should be noted that... Figure 7 The quantum computing circuit shown is merely an example and is not intended to limit the scope of protection of this application. Figure 7 The illustrated embodiment uses a quantum computing circuit consisting of 5 qubits, with N=5, x=3, y=3, and z=3 as an example.

[0081] In one embodiment, the 5 qubits of information to be encrypted are processed... Figure 7 The quantum computing circuit shown outputs a fully quantized state corresponding to 2. 5 The density matrix is ​​the encrypted information after encrypting the 5 qubits to be encrypted.

[0082] In one embodiment, the 5-qubit information to be encrypted is processed... Figure 7 The quantum computing circuit shown outputs a fully quantized state corresponding to 2. 5 The density matrix is ​​then used. Two reduction methods are applied to the five qubit states obtained after processing the quantum computing circuit to find the bias trace. One method involves reducing the (5-3) = 2 qubits in the five qubit states to obtain the bias trace. 3 The reduced density matrix, this 2 3 The reduced density matrix is ​​the first encrypted information; another method is to reduce 3 qubits out of the 5 qubit states obtained after processing the quantum computing circuit and calculate the bias trace to obtain 2. 2 The reduced density matrix, this 2 2 The reduced density matrix is ​​the second encrypted information. Here, the first and second encrypted information are used as the encrypted information after encrypting the 5 qubits to be encrypted.

[0083] In one embodiment, the 5 qubits of information to be encrypted are processed... Figure 7 The quantum computing circuit shown outputs a fully quantized state corresponding to 2. 5The density matrix is ​​obtained, and then, after performing a quantum Fourier transform on the three qubit states, the 2D density matrix corresponding to the full qubit state is obtained. 5 The real density matrix is ​​the third encrypted information and 2 5 The imaginary part density matrix is ​​the fourth encryption information. Here, the third and fourth encryption information are used as the encrypted information after encrypting the 5 qubits to be encrypted.

[0084] In one embodiment, the 5 qubits of information to be encrypted are processed... Figure 7 The quantum computing circuit shown outputs a fully quantized state corresponding to 2. 5 The density matrix is ​​obtained, and then, after performing a quantum Fourier transform on the three qubit states, the 2D density matrix corresponding to the full qubit state is obtained. 5 The real density matrix and 2 5 The imaginary part density matrix is ​​then determined. Subsequently, two reduction methods are applied to the five qubit states after the quantum Fourier transform to obtain the partial trace. One method involves reducing two qubits to obtain the partial trace, resulting in 2... 3 The reduced real density matrix is ​​the fifth encrypted message and 2 3 The reduced imaginary part density matrix is ​​the sixth encrypted information. Another method is to reduce the remaining 3 qubits out of 5 qubits and obtain the partial trace to get 2. 2 The reduced real density matrix is ​​the seventh encrypted message and 2 2 The reduced imaginary part density matrix is ​​the eighth encrypted information. Here, the fifth, sixth, seventh, and eighth encrypted information are the encrypted information after the five qubits to be encrypted are encrypted.

[0085] Figure 8 This is a schematic diagram of the color chart of quantum encryption information in the embodiments of this application, such as... Figure 8 As shown, still in Figure 7 For example, in one embodiment, after performing a quantum Fourier transform on the first three qubit states, taking the input state |0>|0>|0>|0>|0>|0> as the information to be encrypted, the quantum state output obtained in this embodiment is visualized in two dimensions. Figure 8 The color chart shown is based on the 2 corresponding to the full quantum state. 5 The real density matrix (e.g.) Figure 8 (as shown in the left figure) and 2 5 The density matrix of the imaginary part (e.g.) Figure 8 The right-hand image shows a two-dimensional color chart. It should be noted that... Figure 8 Although it has been processed into grayscale, it can actually be in color.

[0086] In one exemplary embodiment, this application also provides a quantum communication method, comprising: a sender encrypting a bit to be encrypted according to any quantum encryption method in this application embodiment to obtain encrypted information; and transmitting the obtained encrypted information to at least one receiver. This application also provides a quantum communication method comprising: a receiver receiving encrypted information and processing the received encrypted information according to the reverse process corresponding to any quantum encryption method in this application embodiment to restore the bit to be encrypted. In any quantum encryption method in this application embodiment, the quantum computing circuit is equivalent to the encryption rules pre-communicated by the communicating parties. The sender calculates the bit to be encrypted according to the quantum computing circuit, and transmits the encrypted information, consisting of the quantum state after the change in its state, as the bit to be encrypted to the receiver; the receiver then uses the reverse quantum computing circuit of the quantum computing circuit to process the received encrypted information to restore the bit to be encrypted, thereby achieving secure quantum communication.

[0087] Figure 9 This is a schematic diagram of the composition structure of the quantum encryption device in the embodiments of this application, as shown below. Figure 9 As shown, it includes at least: a preprocessing module and a first processing module; wherein,

[0088] The preprocessing module is configured to pre-set the quantum computing circuitry;

[0089] The first processing module is configured to input the bit to be encrypted into the quantum computing circuit, causing the input qubit to undergo ecological changes, thereby obtaining encrypted information composed of quantum states.

[0090] The quantum encryption device provided in this application embodiment cleverly and simply encrypts the input bits by causing ecological changes through a pre-configured quantum computing circuit. Thus, in quantum communication, by transmitting encrypted information after encrypting the bits to be encrypted, the security and confidentiality of transmitted information are further improved. Moreover, the quantum encryption method provided in this application embodiment simply enables quantum encryption operations on a classical computer.

[0091] In one exemplary instance, a second processing module may also be included, configured to:

[0092] The partial information in the information processed by the quantum computing circuit is subjected to at least one reduction to obtain a partial trace, wherein the partial information in each reduction partial trace is not repeated, and at least one result of the reduction partial trace is used as the encrypted information after encrypting the bit to be encrypted.

[0093] In one exemplary instance, a third processing module may also be included, configured to:

[0094] Perform a quantum Fourier transform on at least two qubit states in the information processed by the quantum computing circuit to obtain the third and fourth encrypted information; use the third and fourth encrypted information as the bits to be encrypted to encrypt the encrypted information.

[0095] In one exemplary instance, a fourth processing module may also be included, configured as follows:

[0096] The partial information obtained by quantum Fourier transform is subjected to at least one reduction to obtain a partial trace, wherein the partial information in each reduction partial trace is not repeated, and at least one result of the reduction partial trace is used as the encrypted information after encrypting the bit to be encrypted.

[0097] Although the embodiments disclosed in this application are as described above, the content described is merely for the purpose of understanding this application and is not intended to limit this application. Any person skilled in the art to which this application pertains may make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in this application; however, the scope of patent protection of this application shall still be determined by the scope defined in the appended claims.

Claims

1. A quantum encryption method, comprising: Pre-setting a quantum computing circuit; Inputting bits to be encrypted into the quantum computing circuit, so that the input bits change in state, and encrypted information composed of quantum states is obtained; Performing multiple reduced partial trace operations on the quantum bit states after the quantum computing circuit processing, each reduced partial trace operation being performed on part of the quantum bits in the quantum bit states after the quantum computing circuit processing, wherein the corresponding part of quantum bits processed by each reduced partial trace operation does not overlap with each other, and the results after the multiple reduced partial trace operations contain all the input state information after being combined; and using at least one result obtained by the reduced partial trace operation as the encrypted information of the bits to be encrypted.

2. The quantum encryption method of claim 1, wherein, The bits to be encrypted are N bits; the information processed by the quantum computing circuit is a quantum state corresponding to N bits Density matrix The multiple reduced partial trace operations include two reduced partial trace operations, including: reducing the N-x qubits in the N-qubit state obtained after processing the quantum computing circuit to obtain a reduced density matrix, which the reduced density matrix is the first encrypted information; and The x quantum bits in the N quantum bit states obtained after processing the quantum computing circuit are reduced to obtain a partial trace The reduced density matrix is the second encryption information. The reduced density matrix is the second encryption information. wherein x is any one of 1 to N-1.

3. The quantum encryption method of claim 1, further comprising: performing quantum Fourier transform on at least two quantum bit states in the information after the quantum computing circuit processing to obtain third encrypted information and fourth encrypted information; using the third encrypted information and the fourth encrypted information as the encrypted information of the bits to be encrypted.

4. The quantum encryption method of claim 3, wherein, The bits to be encrypted are N bits; the information processed by the quantum computing circuit is a quantum state corresponding to N bits Density matrix The quantum Fourier transform on at least two quantum bit states in the information after the quantum computing circuit processing to obtain third encrypted information and fourth encrypted information, comprising: performing quantum Fourier transform on the y quantum bit states processed by the quantum computing circuit to obtain a full quantum bit state corresponding to a real part density matrix of dimension y and an imaginary part density matrix of dimension y, wherein y is any value in 2~N; the real part density matrix of dimension y is the third encrypted information, and the imaginary part density matrix of dimension y is the fourth encrypted information. an imaginary part density matrix of dimension y, wherein y is any value in 2~N; the real part density matrix of dimension y is the third encrypted information, and the imaginary part density matrix of dimension y is the fourth encrypted information. an imaginary part density matrix of dimension y, wherein y is any value in 2~N; the real part density matrix of dimension y is the third encrypted information, and the imaginary part density matrix of dimension y is the fourth encrypted information.

5. The quantum encryption method of claim 3, wherein, The bits to be encrypted are N bits; the information processed by the quantum computing circuit is a quantum state corresponding to N bits Density matrix The quantum Fourier transform on at least two quantum bit states in the information after the quantum computing circuit processing, comprising: performing quantum Fourier transform on the y quantum bit states processed by the quantum computing circuit to obtain a full quantum bit state corresponding to a real part density matrix and an imaginary part density matrix; wherein y is any value in 2~N. performing at least one reduced partial trace operation on part of the information obtained by the quantum Fourier transform, comprising: reducing the N-z quantum bits of the N quantum bit state obtained after the quantum Fourier transform to obtain a reduced real part density matrix and a reduced imaginary part density matrix; the the reduced real part density matrix is a fifth encrypted information, and the reduced imaginary part density matrix is a sixth encrypted information; reducing the z qubits of the N qubit state obtained after the quantum Fourier transform to obtain a reduced real part density matrix and a reduced imaginary part density matrix; the the reduced real part density matrix is a seventh encrypted information, the the reduced imaginary part density matrix is an eighth encrypted information; wherein z is any one of 1 to N-1.

6. The quantum encryption method of any one of claims 1-5, further comprising: drawing a color card reflecting the encrypted information according to the size of the matrix element of the density matrix corresponding to the encrypted information obtained after the bits to be encrypted are encrypted.

7. A quantum communication method, comprising: a sender encrypting bits to be encrypted according to the quantum encryption method of any one of claims 1-5 to obtain encrypted information; transmitting the obtained encrypted information to at least one receiver.

8. A quantum communication method, comprising: a receiver receiving encrypted information and processing the received encrypted information according to the reverse process of the quantum encryption method of any one of claims 1-5 to obtain the bits to be encrypted.

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