Method and system for performing secure transactions

Abstract

A system includes a remote quantum terminal configured to generate a random number, store the random number, and transmit the random number to a local quantum terminal over a quantum channel that encodes the random number into quantum information using a perfect or quasi-perfect password and a quantum key distribution (QKD) protocol. The local quantum terminal is configured to receive quantum information from the remote quantum terminal through the quantum channel, determine a random number based on the quantum information received from the remote quantum terminal, and transmit the random number to the secure smart card through the quantum channel. The secure smart card is configured to receive a random number from the local quantum terminal over the non-quantum channel, store the random number, and perform a secure transaction between the secure smart card and the remote quantum terminal.

Description

[0001] Related Applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 331,319, filed on April 15, 2022, entitled “METHODS AND SYSTEMS FOR PERFORMING SECURE TRANSACTIONS,” the contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to methods and systems for performing secure transactions, and more particularly, to entropy-based payment methods and systems that are resistant to attacks from quantum computing technology. Background Art

[0004] Quantum computers are devices that use the properties of quantum physics to store data and perform calculations. For example, quantum computers can perform calculations using qubits, which can be in a coherent superposition of two states at the same time, representing both 0 and 1 at the same time. This is in stark contrast to the way traditional computers perform calculations, which use transistors that represent either 0 or 1.

[0005] Quantum computers have significantly higher computing power than classical computers for certain tasks. For example, a 30-qubit quantum computer has roughly the same computing power as a 10 teraflops (10 trillion floating-point operations per second) classical computer. Typical desktop computers run at petaflops (billions of floating-point operations per second).

[0006] The significantly enhanced computing power of quantum computers makes transactions based on traditional encryption technologies (such as public / private key encryption methods) increasingly vulnerable to brute force cracking or other attacks. As a result, payment methods based on these encryption technologies are becoming increasingly insecure and susceptible to illegal intrusion by quantum computers.

[0007] While quantum computers, quantum communication devices, and quantum communication channels can be used instead of traditional computers to defend against these vulnerabilities, the deployment and operation of quantum devices are often impractical and costly.

[0008] Therefore, there is a need for improved methods and systems for performing secure transactions (such as payment transactions) that are resistant to attacks using quantum computing technology. Summary of the invention

[0009] According to one embodiment of the present application, an entropy-based payment system is disclosed. The system includes a remote quantum terminal, which is configured to generate a random number, store the random number, and transmit the random number to a local quantum terminal through a quantum channel, which uses a perfect cryptography or a quasi-perfect cryptography and a quantum key distribution (QKD) protocol to encode the random number as quantum information. The local quantum terminal is configured to receive quantum information from the remote quantum terminal through a quantum channel, determine a random number based on the quantum information received from the remote quantum terminal, and send the random number to a secure smart card through a non-quantum channel. The secure smart card is configured to receive a random number from the local quantum terminal through a non-quantum channel, store the random number, and perform a secure transaction between the secure smart card and the remote quantum terminal using at least a portion of the random number stored in the secure smart card and at least a portion of the random number stored in the remote quantum terminal; wherein, at least a portion of the random number is used as an encryption key for an encrypted transaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a block diagram of an exemplary system based on entropy payment provided by some embodiments of the present application.

[0011] Figure 2 Detailed description is a message sequence chart provided by some embodiments of the present application, which illustrates an exemplary process of loading entropy (which is also stored on a remote server) into a secure smart card and performing a secure transaction using the stored entropy.

[0012] Figure 3 Detailed Description of the Invention 1 is a flowchart provided by some embodiments of the present application, which illustrates exemplary steps of loading entropy (which is also stored on a remote server) into a secure smart card and performing a secure transaction using the stored entropy. DETAILED DESCRIPTION

[0013] The subject matter described in this application includes an entropy-based payment method and system. One embodiment of the present application discloses an entropy-based payment system. The system includes a remote quantum terminal, which is configured to generate a random number, store the random number, and transmit the random number to a local quantum terminal through a quantum channel, which uses a perfect cryptography or a quasi-perfect cryptography and a quantum key distribution (QKD) protocol to encode the random number as quantum information. The local quantum terminal is configured to receive quantum information from the remote quantum terminal through a quantum channel, determine a random number based on the quantum information received from the remote quantum terminal, and send the random number to a secure smart card through a non-quantum channel. The secure smart card is configured to receive a random number from the local quantum terminal through a non-quantum channel, store the random number, and perform a secure transaction between the secure smart card and the remote quantum terminal using at least a portion of the random number stored in the secure smart card and at least a portion of the random number stored in the remote quantum terminal; wherein the at least a portion of the random number is used as an encryption key for an encrypted transaction.

[0014] As described above, the computing power of quantum computers makes transactions based on traditional encryption technology vulnerable to brute force or other attacks. The present application protects transactions from the computing power of quantum computers, and at the same time, even when quantum communication channels are not available, the present application allows users to communicate securely with remote servers through non-secure traditional communication channels. The subject matter described in the present application for generating, storing and using entropy in order to, for example, perform secure transactions or exchange secure message content can be divided into two stages. First, the secure smart card can be loaded with entropy. This can include receiving a long random number sequence generated on a remote server (e.g., a remote quantum terminal) and storing the random number sequence in a memory of the secure smart card. The user can carry a secure smart card loaded with entropy for later use. In this case, the same random number sequence is stored on both the server and the secure smart card. Once the secure smart card contains a random number sequence (entropy), the secure smart card can use at least a portion of the random number sequence to perform secure transactions on a non-quantum channel. For example, when a user wishes to perform a payment transaction, the secure smart card can determine an encryption key k from the random number sequence so that the size of k is equal to or greater than the information encrypted using k. For example, a message containing "Hello" can include five characters and be encrypted using an encryption key k of at least five characters.

[0015] Figure 1 is a block diagram of an exemplary system based on entropy payment provided by some embodiments of the present application. Figure 1 , an exemplary system 100 includes a secure smart card (SSC) 102 , a local quantum terminal (LQT) 104 , and a remote quantum terminal (RQT) 106 .

[0016] A smart card is a portable terminal device, usually about the size of a portable credit card, which includes a microprocessor, a memory, and related circuits and computer executable instructions for implementing a communication protocol, wherein the communication protocol may be a protocol such as near field communication (NFC). The secure smart card (SSC) mentioned in this application is a smart card, which includes modifications or additions to a microprocessor, a memory, related circuits, and computer executable instructions for implementing the functions disclosed in this application. For example, in order to store a long random number sequence (received entropy used as an encryption / decryption key), the memory of the SSC may be larger than the memory of a traditional smart card. The processor of the SSC may be further configured to perform encryption and / or decryption algorithms. The SSC may also include a display and an input / output terminal (physical or virtual keyboard) that are not usually included on a traditional smart card. In another embodiment, a portable terminal, such as a smart phone or a mobile device, is used instead of a separate smart card to implement the SSC.

[0017] A quantum terminal is a communication device that can transmit quantum information through a quantum channel. As will be discussed in more detail below, quantum information can include, for example, information using binary quantum states or qubits. A quantum channel includes a transmission medium and associated quantum key distribution protocols that enable information encoded using binary quantum states to be securely transmitted. For example, a sending quantum terminal can send a pulse sequence (e.g., a femtosecond pulse with a repetition rate of 80 MHz) to a receiving quantum terminal through a quantum channel, each pulse comprising a single photon of different polarization.

[0018] A local quantum terminal is a quantum terminal that includes both quantum channel communication capabilities and traditional channel communication capabilities. Traditional communication capabilities include any type of standard wired or wireless technology required to communicate with a secure smart card. For example, communication can use NFC, Wi-Fi, or 4G / 5G mobile communication protocols. It should be understood that although local quantum terminals are not currently portable or mobile due to limitations in communicating on quantum channels, local quantum terminals are not limited to non-portable or non-mobile embodiments. In one embodiment, the local quantum terminal can be an automated teller machine (ATM) or a point of sale (POS) terminal, or can be integrated with an automated teller machine (ATM) or a point of sale (POS) terminal. Relative to a secure smart card, a local quantum terminal is a quantum terminal located locally. For example, for a secure smart card that communicates with a local quantum terminal via NFC, the secure smart card and the local quantum terminal must be close to each other (e.g., the range of NFC is about 20 cm).

[0019] On the other hand, the remote quantum terminal is far away from the local quantum terminal and the secure smart card. Like the local quantum terminal, the remote quantum terminal includes both quantum channel communication capabilities and traditional channel communication capabilities. The remote quantum terminal is also generally not a mobile or portable device. Unlike each local quantum terminal (e.g., LQT1-LQTn) that communicates with one remote quantum terminal, the remote quantum terminal can communicate with multiple local quantum terminals. In this way, the remote quantum terminal acts as the center of a star network hosting multiple local quantum terminals, where the remote quantum terminal is connected to many quantum terminals using corresponding quantum channels (e.g., QC1-QCn).

[0020] It will be appreciated that the system described herein may include devices (smart card 102, local quantum terminal 104, and remote quantum terminal 106) connected by a plurality of different communication channels (traditional channel 108 and quantum channel 110). Quantum channel 110 is a channel in which quantum states of light encoded with random bits are transmitted between devices. Quantum channel 110 is a transport pathway that helps light to be transmitted between nodes. For example, it may be an optical dark fiber link or a free space connection. Traditional channel 108 is a traditional communication channel, such as may be found in an Ethernet-based local area network, a Wi-Fi link, a fiber channel link, or a similar communication channel. Data transmitted over traditional channel 108 may be protected by a message authentication code (MAC) to authenticate the identity of the device transmitting over the channel.

[0021] The SSC 102 may communicate with the LQT 104 via a conventional communication channel (CC) 108. A communication channel refers to a logical connection over a physical transmission medium (e.g., metal wire, fiber optic cable, or air) or a multiplexed medium, such as a radio channel in telecommunications and computer networks. The channel is used to transmit information signals (e.g., messages, byte streams, photons) between a sender and a receiver. The CC 108 may include any wired or wireless communication link that is a non-quantum channel (i.e., does not transfer quantum information). For example, the CC 108 may be a twisted pair Ethernet cable, a coaxial cable, or a glass fiber optic cable. The CC 108 may also be a wireless connection, such as a near field communication (NFC) protocol connection, a Wi-Fi connection, or a cellular (e.g., 4G or 5G) mobile connection.

[0022] The SSC 102 may include a CC interface 112 for sending and receiving information through the CC 108. For example, the CC interface 112 may be an Ethernet adapter that allows the SSC 102 to communicate with the LQT 104 via a twisted pair Ethernet cable. Alternatively, the CC interface 112 may be an NFC wireless signal that allows the SSC 102 to communicate with the LQT 104 wirelessly. It is understood that the CC 112 may include any suitable conventional communication device for communicating with a corresponding CC interface 114 on the LQT 104.

[0023] LQT 104 may include a CC interface 114 for communicating with SSC 102 via CC 108 and a quantum channel (QC) interface 116 for communicating with RQT 106 via quantum channel 110 .

[0024] A quantum channel (e.g., QC110) is a communication channel that can transmit quantum information. Quantum channels can also transmit traditional information. Quantum information is information about the state of a quantum system. Therefore, quantum communication involves using binary quantum states, or qubits, to process information, rather than the binary digits, or bits, used in traditional communication. In traditional computing, bits (usually characterized as 0 or 1) are used to represent information. In quantum computing, qubits are used to represent quantum information. For example, qubits can be used to encode information by imparting spin to electrons, where the two states are spin up and spin down. In another example, quantum information can be encoded using the polarization of a single photon, where the two states are vertical polarization and horizontal polarization. In traditional systems, bits must be in one state or the other. However, quantum mechanics allows qubits to be in a coherent superposition of two states at the same time, which is a fundamental property of quantum mechanics and quantum computing.

[0025] As used in this application, a quantum channel also refers to a communication channel that transmits quantum information (also known as "entropy") between, for example, LQT104 and RQT106 using a perfect cryptography (PC) or quasi-perfect cryptography (QPC) via a quantum key distribution (QKD) protocol. Unlike traditional public key cryptography, which relies on the computational difficulty of certain mathematical functions and is susceptible to quantum computing technology, the encryption security using quantum key distribution relies on quantum mechanics. Therefore, compared to traditional channels, communications using quantum channels are protected by the properties of quantum physics. The security of a communication channel refers to the assurance that the content of an encrypted message transmitted between a sender and a receiver is not copied, intercepted, and decrypted by anyone other than the intended recipient. Contrary to traditional physics, the act of measuring an unknown quantum state changes this state in some way. In addition, quantum entanglement describes that if a pair of entangled objects are shared between two parties, anyone who intercepts one of the objects will change the entire system, exposing the existence of a third party (and the amount of information they have obtained). These properties of quantum physics can be used to detect eavesdropping on quantum communications.

[0026] In one example, the Bennett-Brassard-84 (BB84) QKD protocol uses a quantum channel to provide secure communication between two parties. The security of BB84 comes from encoding information in non-orthogonal states, which cannot be measured without disturbing the original states. BB84 uses two pairs of states, each pair is conjugated to the other pair, and the two states in a pair are orthogonal to each other. Pairs of orthogonal states are considered to be bases. Exemplary pairs of polarization states are straight line bases of vertical (0°) and horizontal (90°), or diagonal bases of 45° and 135°.

[0027] The BB84 protocol can be initiated with a sender and receiver connected via a quantum communication channel that allows for the transmission of quantum states. The sender can begin quantum transmission by creating a random bit (0 or 1) and then randomly selecting one of two bases (e.g., straight or diagonal). The sender then prepares the polarization state of the photon according to the bit value and the basis (e.g., 0 is encoded as a perpendicular polarization state in the straight basis and 1 is encoded as a 135° state in the diagonal basis). The sender then uses the quantum channel to send a single photon to the receiver in the specified state. This process is then repeated, with the sender recording the state, basis, and time for each photon sent. Since the receiver does not know the basis in which the photon is encoded, the receiver randomly selects a basis, and for each photon received, the receiver records the time, the measurement basis used, and the measurement result. After the receiver measures all photons, the receiver communicates with the sender via a non-quantum channel to compare the basis used to transmit each photon with the basis used to measure each photon. Photon measurements using different bases by the sender and receiver are discarded, and the remaining bits are used as a shared key. Other exemplary QKD protocols include the Bennett-92 (B92) protocol and the entanglement-based Ekert-91 (E91) protocol.

[0028] Returning to QC110, a cipher is an algorithm used to perform encryption and decryption of information. Encoding using a cipher is the conversion of the original message (called plaintext) into ciphertext using a key. Decoding is the conversion of ciphertext into plaintext using a key. It is understood that a message can be encrypted and decrypted with a key k, or encrypted with a key k and decrypted with a key k', where k' is different from k.

[0029] A perfect cipher is one that can never be broken, even with infinite time and infinite computing power. As used herein, a perfect cipher assumes that an attacker (i.e., an unwelcome third-party eavesdropper) knows only the ciphertext c and attempts to find either the plaintext m or the key k. A perfect cipher is one where, given the ciphertext c, the probability that the plaintext is some m is equal to the probability that the message is m. In other words, knowing the ciphertext does not give the attacker any additional information about the message compared to pure guessing.

[0030] The following terms: (M, C, K, E k , D k ) can be defined as:

[0031] M is the set of plain texts, i.e. plain text

[0032] C is the set of encrypted texts, i.e. ciphertext

[0033] K is the set of possible keys

[0034] ·E k is an encryption function, where E k is a function of k and m, k∈K and m∈M

[0035] ·D k is the decryption function, where D k is a function of k and c, k∈K and c∈C

[0036] Function E k :M–>C is injective, that is, reversible to the left, and there exists a key k' such that for every element m in the set M, D k '(E k (m)) = m;

[0037] When k=k', it is symmetric encryption. When k and k' are different, it is asymmetric encryption. In the case of symmetric keys, key k is a secret key that both parties use to encrypt and decrypt messages. In the case of asymmetric keys, key k is a public key and key k' is a private key.

[0038] Assume that the plaintext m, key k and ciphertext c are three random discrete variables: X M , X K X C , where the probability distribution is known.

[0039] Assume X M , X K X C independent, and the probability of each element m∈M, k∈K is non-zero. Or, in other words, for each m∈M, P(X M =m)>0, for each k∈K, P(X K =k)>0.

[0040] Understandable, X M X C X K and X C Not necessarily independent.

[0041] For every m∈M and c∈C, when P(X M =m|X C =c) = P(XM =m), the perfect password (PC) is perfect.

[0042] In every perfect cipher, |K|>|M|.

[0043] In the case where k and m use the same alphabet (same set of symbols), the length of key k is preferably equal to or longer than text m, because the best security level is when the key is at least equal to the message. In other embodiments, the length of key k can be less than text m. However, it will be appreciated that as the ratio k:m decreases from 1:1 to 1:2 or 1:10, encryption with a key k that is shorter than text m becomes increasingly unsafe. If a key that is significantly smaller than the message is a key that is less than 10% of the message, a key k that is smaller than, but not significantly smaller than, the length of the message can be used. Therefore, in one embodiment, a minimum key length relative to 10% of the message length can be a minimum threshold for the length of key k.

[0044] Assumption E k is injective, then |C|≥|M|. If for the illogical |K|<|M|≤|C|, then for every m∈M, there will be a c m ∈C, it cannot be generated by m through any k∈K, or in other words, c m {E k (m)|k∈K}(In fact,|{E k (m)|k∈K}|≤|K|).

[0045] A perfect password will have:

[0046] P(X M =m) = P(X M =m|X C =c m )=0, but for every m∈M, P(X M =m)>0.

[0047] A quasi-perfect cipher (QPC) is a cipher for which |K| <= |M|.

[0048] As mentioned above, the computing power of quantum computers makes transactions based on traditional cryptographic techniques, such as public / private key encryption methods, where |K|<|M|, increasingly vulnerable to brute force or other attacks. As a result, payment methods based on these traditional cryptographic techniques are becoming increasingly insecure because they are easily hacked by quantum computers. For example, quantum computers can brute force attacks on transactions based on hash functions (e.g., blockchain) because |K|<|M| in these cases.

[0049] The present application protects transactions from the computational power of quantum computers while maintaining practical considerations when quantum communication channels are not available, such as allowing users to use a mobile secure smart card (which has been pre-loaded with entropy / communicates with a remote quantum terminal through a local quantum terminal and a quantum channel) to securely communicate with a remote server through an insecure conventional communication channel.

[0050] The subject matter described in this application for generating, storing and using entropy in order to, for example, perform secure transactions or exchange secure message content can be divided into two stages. First, the secure smart card can be loaded with entropy. This can include receiving a long random number sequence generated on a remote server (e.g., a remote quantum terminal) and storing the random number sequence in a memory of the secure smart card. In order to ensure the best security of transmitting random numbers from a remote server to a secure smart card, an intermediate device can be used. For example, a local quantum terminal can communicate directly with a remote quantum terminal and then relay the information to the secure smart card.

[0051] Since secure communication over quantum channels requires specialized equipment, such quantum communication is typically expensive, non-mobile, and slow. For example, polarized photons can be transmitted between a remote quantum terminal (e.g., connected to or integrated with a bank server) and a local quantum terminal in the form of a POS or ATM terminal via a dedicated optical cable. Therefore, it may be impractical to integrate or implement these specialized quantum devices into small portable devices such as smart cards or mobile phones. Instead, portable devices such as smart cards and mobile phones can communicate over non-quantum or conventional channels such as Wi-Fi, NFC, etc.

[0052] Therefore, the local quantum terminal can include quantum communication capabilities as well as non-quantum communication capabilities. This allows a single local quantum terminal to act as an intermediary between a single remote quantum server and multiple secure smart cards. The local quantum terminal can receive quantum information encoding a random number sequence from a remote quantum terminal, extract or decode the random number sequence, and forward the random number sequence to a secure smart card using the non-quantum communication capabilities of the local quantum terminal.

[0053] In order to transmit the random number sequence from the local quantum terminal to the secure smart card, a communication channel can be established between the secure smart card and the local quantum terminal. For example, a user can place their secure smart card within the physical proximity of the local quantum terminal to communicate via the NFC protocol. Although the information transmitted through this non-quantum channel may not be as secure as the information transmitted through the quantum channel because the non-quantum channel does not use perfect or quasi-perfect cryptography, the security may still be strong due to the physical proximity of the devices and the short communication period. Using the established non-quantum channel, the secure smart card can receive the random number sequence from the local quantum terminal and store the random number sequence in the memory of the secure smart card.

[0054] The non-quantum channel between the secure smart card and the local terminal can then be terminated, and the user can carry the secure smart card, now loaded with entropy, for later use. This results in an exemplary sequence for generating and storing entropy according to an embodiment of the subject matter described in the present application. It will be appreciated that at this point in the exemplary sequence, the same random number sequence is stored on the server and the secure smart card. In addition, by using a quantum channel to transmit the random number sequence over a long distance, the confidentiality of the random number sequence is maintained (i.e., not copied, intercepted, or otherwise obtained by a third party). However, as will be discussed in more detail below, using a non-quantum channel to transmit the random number sequence over a shorter distance allows the use of a more practical device (secure smart card or mobile phone) to perform transactions using the random number sequence.

[0055] Once the secure smart card contains a random number sequence (entropy) that is also stored at a remote quantum terminal, the secure smart card can use at least a portion of the random number sequence to perform a secure transaction over a non-quantum channel. For example, when a user wishes to perform a payment transaction at a point-of-sale terminal, the amount of information to be encrypted can be determined. The secure smart card can then determine an encryption key k from the random number sequence such that the size of k is equal to or greater than the information encrypted using k. Typically, this results in an encryption key k that is longer than a conventional encryption key. In order to keep the amount of data transmitted to a minimum, thereby effectively using the entropy stored on the smart card for as many transactions as possible before needing to be reloaded, portions of the transaction or message that need to be encrypted can be encrypted. For example, a message containing "Hello my social security number is 123-45-6789" can encrypt the portion containing "123-45-6789" using key k. This can reduce the length of key k from approximately 38 characters to 9 characters (approximately 29 characters in "Hello my social security number is" can be unencrypted or encrypted using an encryption key other than key k).

[0056] Figure 2 is a message sequence chart provided by some embodiments of the present application, which shows an exemplary process for loading entropy (which is also stored on a remote server) into a secure smart card and performing a secure transaction using the stored entropy. Figure 2The process 200 is divided into a first set of steps 200 and a second set of steps 212, wherein the first set of steps 200 is used to load entropy into the secure smart card and the second set of steps 212 is used to perform a secure transaction using the stored entropy. It will be appreciated that both sets of steps 200 and 212 may occur as part of the same transaction or may occur separately at different times and / or locations. The process 200 begins at step 202 when the RQT 106 generates a random number sequence. The random number sequence may be based on a quantum physics process. Alternatively, a QKD protocol may be used to generate the random number sequence. In other embodiments, a conventional algorithmic pseudo-random number generator may be used to generate the random numbers. Once the random numbers are generated, they may be stored in a memory associated with the RQT 106.

[0057] Random numbers can be generated starting from physical phenomena, such as random emission of photons or beta decay or thermal effects. Quantum physical phenomena can produce high-quality entropy sources, which cannot be replaced by any algorithm. The entropy generator (EG) is a physical generator of entropy that provides random numbers (sequence SQ1) stored in secure smart cards and remote quantum terminal memories. Quantum key distribution protocols may require a random number source to work properly (usually there are three generators, but it depends on the QKD protocol). In order to reduce the cost of the random number generator, SQ1 can also be provided by the QKD protocol, where the function of the entropy generator (RNG) is replaced by the key distributed by the QKD protocol.

[0058] In step 204, the random number sequence is encoded as quantum information and transmitted to LQT 104. For example, a pulse sequence may be transmitted to LQT 104 via a quantum channel, where each pulse contains a single photon of a different polarization. In step 206, LQT 104 receives and decodes the quantum information to determine the random number sequence encoded therein. In step 208, LQT 104 sends the random number sequence to SSC 102 via a non-quantum channel. For example, an NFC connection may be established between SSC 102 and LQT 104. In step 210, the random number sequence is received and stored at SSC 102.

[0059] Step 212 (Performing a Secure Transaction Using Stored Entropy) begins at step 214 when the SSC 102 selects an encryption key k from a stored random number sequence. It will be appreciated that the encryption key k may include the entire stored random number sequence or a portion of the stored random number sequence. Once the encryption key k is determined, in step 216, a connection may be established using the encryption key k. This may include sending the key to the RQT 106 for verification. The RQT 106 may compare the key recovered from the SSC 102 when establishing the connection with the key previously stored in step 202. If the keys match, the connection may be secure.

[0060] In step 218, encryption key k may be used to encrypt communications between SSC 102 and RQT 106. These communications may be associated with, for example, a payment transaction. Once key k is used to perform a transaction, key k (which may represent a portion of the entire available random number sequence) may be deleted from SSC 102 and RQT 106. The amount of remaining entropy stored on SSC 102 may be displayed to the user.

[0061] Figure 3 is a flowchart provided by some embodiments of the present application, which shows example steps of loading entropy (the entropy is also stored on a remote server) to a secure smart card and performing a secure transaction using the stored entropy.

[0062] In step 300, a random number is generated at a remote quantum terminal. In one embodiment, generating the random number includes using a quantum key distribution (QKD) protocol to generate a shared random key that can be used to encrypt and decrypt messages. In another embodiment, generating the random number includes generating the random number based on a quantum physical process, which can be at least one of radioactive decay, polarization, or thermal effects of at least one of photons and electrons.

[0063] In step 302, a random number is stored in a memory of a remote quantum terminal.

[0064] In step 304, the random number is transmitted from the remote quantum terminal to the local quantum terminal via a quantum channel, wherein the quantum channel encodes the random number as quantum information using perfect cryptography or quasi-perfect cryptography and a quantum key distribution (QKD) protocol. In one embodiment, encoding and communicating the random number as quantum information includes using at least one of the following QKD protocols: Bennett-Brassard-84 (BB84), Bennett-92 (B92), and Ekert-91 (E91).

[0065] In step 306, the local quantum terminal receives quantum information from the remote quantum terminal through the quantum channel. In step 308, the local quantum terminal determines a random number based on the quantum information received from the remote quantum terminal. For example, the local quantum terminal can measure quantum properties of quantum particles, such as measuring at least one of radioactive decay, polarization, or thermal effects of particles, including but not limited to photons and electrons.

[0066] In step 310, the random number is transmitted from the local quantum terminal to the secure smart card through a non-quantum channel, and in step 312, the secure smart card receives the random number from the local quantum terminal through the non-quantum channel. For example, receiving the random number from the local quantum terminal through the non-quantum channel includes using at least one of a wired connection, a wireless connection, a Wi-Fi connection, an Ethernet cable, a near field communication (NFC) protocol, a 4G mobile connection, and a 5G mobile connection.

[0067] In step 314, the random number is stored in a memory of the secure smart card. In one embodiment, storing the random number in the memory includes storing the random number as a data packet, wherein each data packet is associated with at least one of a timestamp, an incrementing number, and a unique identifier of the secure smart card.

[0068] In step 316, a secure transaction is performed between the secure smart card and the remote quantum terminal using at least a portion of the random number stored in the secure smart card and at least a portion of the random number stored in the remote quantum terminal, wherein the at least a portion of the random number is used as an encryption key for the encrypted transaction. For example, the at least a portion of the random number can be used as a password for communication between the secure smart card and the remote quantum terminal through a non-quantum channel. When the SSC communicates with the RQT through a non-secure (NSC) network, the communication is performed using the entropy of the password k stored as a perfect password or a quasi-perfect password.

[0069] In one embodiment, when any or all of the random numbers are used to perform a transaction, the portion of the random numbers used and the remaining portion of the random numbers stored on the secure smart card may be displayed. In another embodiment, the portion of the random numbers used to perform the secure transaction may be deleted from the memory of the secure smart card and / or the remote quantum server, and it is understood that the random numbers stored on the secure smart card may be the same as the random numbers stored on the remote quantum terminal.

[0070] The configuration described in this application enables a device (e.g., a remote quantum terminal) to exchange quantum cryptographically protected data from multiple local quantum terminals using a quantum channel that uses perfect or quasi-perfect cryptography and a quantum key distribution protocol for encoding random numbers as quantum information. In addition, each terminal can contain an asymmetric or symmetric key so that physical damage to one terminal or channel does not affect previous transactions of other terminals or damaged terminals. The configuration described in this application can use a random number generator (RN) including modular operations to derive random keys from a key space such as an Advanced Encryption Standard (AES) 256-bit space. The configuration described in this application can also support symmetric algorithms (e.g., the AES algorithm).

[0071] As disclosed in the present application, it will be appreciated that random numbers are used for various purposes, including as input to a quantum key distribution (QKD) system. Therefore, it is desirable that the random numbers (e.g., bit streams) generated are unpredictable, where the unpredictability of the bit stream can be quantified by the "entropy" of the stream. Entropy is a fundamental physical quantity that can be used as a measure of the lack of determinism in a system. In information theory, the entropy of a message stream (sometimes called "Shannon entropy") is a measure of the average amount of information required to describe each message. A bit stream that exhibits complete randomness will present an entropy of one bit per bit. This situation is referred to as "full entropy." The method for generating random numbers / bits at a remote quantum terminal disclosed in the present application ensures that the amount of entropy presented by the random bits is not affected by an adversary.

[0072] In one embodiment, the QKD system described herein with local and remote quantum terminals for secure communication therebetween may include a controller with an encryption / decryption module connected thereto. The quantum terminal may also include an optical radiation source (e.g., a laser) and a polarization or phase modulator optically coupled thereto downstream of the optical radiation source.

[0073] As will be appreciated by those skilled in the art, various aspects of the present application may be embodied as a system, method, or computer program product. Therefore, various aspects of the present application may take the form of a complete hardware embodiment, a complete software embodiment (including the form of firmware, resident software, microcode, etc.), or an embodiment combining software and hardware aspects, which are generally referred to as "circuits", "modules", or "systems" in the present application. In addition, various aspects of the present application may take the form of a computer program product embodied in one or more computer-readable media, which have computer-readable program code thereon.

[0074] Any combination of one or more computer-readable media can be utilized. Computer-readable media can be computer-readable signal media or computer-readable storage media (including but not limited to non-transient computer-readable storage media). Computer-readable storage media can be, for example, but not limited to, electrical, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or equipment, or any combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: electrical connections with one or more wires, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices, or any combination of the above. In the context of the present disclosure, computer-readable storage media can be any tangible medium that can contain or store programs used by or related to instruction execution systems, devices or equipment.

[0075] A computer readable signal medium may include a propagated data signal with computer readable program code, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including but not limited to an electromagnetic signal, an optical signal, or any suitable combination of the foregoing. A computer readable signal medium may be any computer readable medium other than a computer readable storage medium that may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0076] Program code on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0077] The computer program code for performing the operation of various aspects of the application can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, Smalltalk, C++ and conventional procedural programming languages ​​such as "C" programming language or similar programming languages. The program code can be executed completely on the user's computer, partially on the user's computer, as an independent software package, partially on the user's computer and partially on a remote computer or completely on a remote computer or server. In the latter case, the remote computer can be connected to the user's computer through any type of network (including local area network (LAN) or wide area network (WAN)), or can be connected to an external computer (for example, using an Internet service provider through the Internet).

[0078] Various aspects of the present disclosure are described below with reference to flowchart illustrations and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present disclosure. It is understood that each block of the flowchart illustration and the block diagram and the combination of the blocks in the flowchart illustration and / or the block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device create a mode for implementing the function / behavior specified in the flowchart and / or block diagram block (or multiple blocks).

[0079] These computer program instructions may also be stored in a computer-readable storage medium that can instruct a computer, a programmable data processing apparatus, or other device to operate in a specific manner, such that the computer-readable storage medium having the instructions stored therein includes an article of manufacture of instructions that implement the functions / behaviors specified in the flowchart and / or block diagram blocks.

[0080] The computer program instructions may also be loaded onto a computer, other programmable data processing device, or other device to perform a series of operational steps on the computer, other programmable device, or other apparatus, thereby producing a computer-implemented process, such that the instructions executed on the computer or other programmable device provide a process for implementing the functions / actions specified in the flowchart and / or block diagram blocks.

[0081] The flowcharts and block diagrams in the accompanying drawings illustrate possible implementations of the systems, methods, and computer program products according to various embodiments of the present disclosure, the architecture, functions, and operations. In this regard, each block in the flowchart or block diagram may represent a module, fragment, or portion of a code, which includes one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than indicated in the accompanying drawings. For example, two blocks shown in succession may in fact be executed substantially simultaneously, or blocks may sometimes be executed in reverse order, depending on the functions involved. It will also be noted that each block in the block diagram and / or flowchart illustration and the combination of blocks in the block diagram and / or flowchart description may be implemented by a dedicated hardware-based system that performs a specified function or behavior or implements a combination of dedicated hardware and computer instructions.

[0082] The terms used in this disclosure are only used for the purpose of describing specific embodiments and are not intended to limit the present application. Unless the context clearly indicates otherwise, as used herein, the singular forms "one", "one (kind / person)" and "the" are also intended to include plural forms. It will be further understood that when the term "comprising" is used in this specification, the stated features, wholes, steps, operations, elements and / or components are present, but the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof are not excluded.

[0083] The corresponding structures, materials, actions, and equivalents of all "means or step plus function" elements in the claims are intended to include any structure, material, or action that performs a function in combination with other elements specifically claimed for protection. The description of the present disclosure is presented for the purpose of illustration and description, but is not intended to be exhaustive or limit the forms disclosed in the present disclosure. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the present disclosure. The embodiments are selected and described in order to best explain the principles of the present disclosure and its practical application, so that other persons of ordinary skill in the art can understand the various embodiments of the present disclosure with various modifications suitable for the specific purposes contemplated.

[0084] The description of various embodiments of the present disclosure is provided for the purpose of illustration and description, but is not intended to be exhaustive or limit the forms disclosed in the present disclosure. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terms selected and used in the present disclosure are intended to best explain the principles of the embodiments, practical applications, or technical improvements to technologies available on the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed in the present disclosure.

Claims

1. A method comprising: Generate random numbers at a remote quantum terminal; Storing the random number in a memory of the remote quantum terminal; Transmitting the random number from the remote quantum terminal to the local quantum terminal through a quantum channel, wherein the quantum channel encodes the random number into quantum information using perfect cryptography or quasi-perfect cryptography and a quantum key distribution (QKD) protocol; The local quantum terminal receives the quantum information from the remote quantum terminal through the quantum channel; The local quantum terminal determines the random number based on the quantum information received from the remote quantum terminal; transmitting the random number from the local quantum terminal to a secure smart card via a non-quantum channel; The secure smart card receives the random number from the local quantum terminal through the non-quantum channel; storing the random number in a memory of the secure smart card; and A secure transaction is performed between the secure smart card and the remote quantum terminal based on at least a portion of the random number stored in the secure smart card and at least a portion of the random number stored in the remote quantum terminal, wherein the at least a portion of the random number is used as an encryption key for the encrypted transaction.

2. The method according to claim 1, wherein: The generating of random numbers comprises: A shared random key is generated using the QKD protocol for encrypting and decrypting messages.

3. The method according to claim 1, wherein: The generating of random numbers comprises: The random number is generated based on a quantum physical process, the quantum physical process comprising measuring a quantum property of a quantum particle, the quantum property comprising at least one of radioactive decay, polarization, or thermal effects.

4. The method according to claim 1, wherein: Storing the random number in the memory comprises: The random numbers are stored as data packets, wherein each data packet is associated with at least one of a timestamp, an incrementing number, and a unique identifier of the secure smart card.

5. The method according to claim 1, wherein: The at least a portion of the random numbers is used as a password, and the password is used for communication between the secure smart card and the remote quantum terminal through a non-quantum channel.

6. The method according to claim 1, wherein: The length of the encryption key is greater than or equal to the length of information encrypted by the encryption key.

7. The method according to claim 1, wherein: The length of the encryption key is less than the length of the information encrypted by the encryption key and is at least ten percent of the length of the information encrypted by the encryption key.

8. A system comprising: A remote quantum terminal, the remote quantum terminal being configured to: Generate random numbers; Storing the random number; as well as Transmitting the random number to a local quantum terminal through a quantum channel, wherein the quantum channel uses perfect cryptography or quasi-perfect cryptography and a quantum key distribution (QKD) protocol to encode the random number into quantum information; A local quantum terminal, the local quantum terminal being configured to: receiving the quantum information from the remote quantum terminal via the quantum channel; determining the random number based on the quantum information received from the remote quantum terminal; and transmitting the random number to a secure smart card via a non-quantum channel; and A secure smart card configured to: receiving the random number from the local quantum terminal through the non-quantum channel; storing the random number; and A secure transaction is performed between the secure smart card and the remote quantum terminal based on at least a portion of the random number stored in the secure smart card and at least a portion of the random number stored in the remote quantum terminal, wherein the at least a portion of the random number is used as an encryption key for the encrypted transaction.

9. The system according to claim 8, wherein: The generating of random numbers comprises: A shared random key is generated using the QKD protocol for encrypting and decrypting messages.

10. The system according to claim 8, wherein: The generating of random numbers comprises: The random number is generated based on a quantum physical process, the quantum physical process comprising measuring a quantum property of a quantum particle, the quantum property comprising at least one of radioactive decay, polarization, or thermal effects.

11. The system according to claim 8, wherein: Storing the random number in the memory comprises: The random numbers are stored as data packets, wherein each data packet is associated with at least one of a timestamp, an incrementing number, and a unique identifier of the secure smart card.

12. The system according to claim 8, wherein: The at least a portion of the random numbers is used as a password, and the password is used for communication between the secure smart card and the remote quantum terminal through a non-quantum channel.

13. The system according to claim 8, wherein: The length of the encryption key is greater than or equal to the length of information encrypted by the encryption key.

14. The system according to claim 8, wherein: The length of the encryption key is less than the length of the information encrypted by the encryption key and is at least ten percent of the length of the information encrypted by the encryption key.

15. A remote quantum terminal, comprising: A random number generator, wherein the random number generator is used to generate random numbers; A memory, the memory being used to store the random number; as well as A quantum channel interface, wherein the quantum channel interface is used to transmit the random number to a local quantum terminal through a quantum channel, wherein the quantum channel uses perfect cryptography or quasi-perfect cryptography and a quantum key distribution (QKD) protocol to encode the random number into quantum information.

16. The remote quantum terminal of claim 15, wherein: The generating of random numbers comprises: A shared random key is generated based on the QKD protocol for encrypting and decrypting messages.

17. The remote quantum terminal of claim 15, wherein: The random number generator generates the random numbers based on a quantum physics process.

18. The remote quantum terminal of claim 15, wherein: The random number generator is used to measure quantum properties of quantum particles, and the quantum properties include at least one of radioactive decay, polarization or thermal effects.

19. The remote quantum terminal of claim 15, wherein: The remote quantum terminal encodes the random number using a QKD protocol and transmits it as quantum information, wherein the QKD protocol includes at least one of the following: Bennett-Brassard-84 (BB84), Bennett-92 (B92) and Ekert-91 (E91).

20. The remote quantum terminal of claim 15, wherein: The remote quantum terminal stores the random numbers as data packets, wherein each data packet is associated with at least one of a timestamp, an incrementing number, and a unique identifier of a secure smart card.

21. The remote quantum terminal of claim 15, wherein: The remote quantum terminal uses at least a portion of the random number as an encryption key, and the encryption key is used to perform a secure transaction between the remote quantum terminal and the secure smart card using at least a portion of the random number stored in a secure smart card and at least a portion of the random number stored in the remote quantum terminal, wherein the length of the encryption key is greater than or equal to the length of information encrypted by the encryption key.

22. The remote quantum terminal of claim 15, wherein: The remote quantum terminal uses at least a portion of the random number as an encryption key, and the encryption key is used to perform a secure transaction between the remote quantum terminal and the secure smart card using at least a portion of the random number stored in a secure smart card and at least a portion of the random number stored in the remote quantum terminal, wherein the length of the encryption key is less than the length of information encrypted by the encryption key, and the length of the encryption key is at least ten percent of the length of the information encrypted by the encryption key.

23. A local quantum terminal, comprising: A quantum channel interface, wherein the quantum channel interface is used to receive quantum information from a remote quantum terminal through a quantum channel; a processor configured to determine a random number based on the quantum information received from the remote quantum terminal; and A non-quantum channel interface is used to transmit the random number to a secure smart card through a non-quantum channel.

24. The local quantum terminal according to claim 23, wherein: The local quantum terminal uses at least a portion of the random number as a password, and the password is used to communicate with the secure smart card through a non-quantum channel.

25. The local quantum terminal according to claim 24, wherein: The local quantum terminal transmits the random number to the secure smart card via at least one of a wired connection, a wireless connection, a Wi-Fi connection, an Ethernet cable, a near-field communication NFC protocol, a 4G mobile connection, and a 5G mobile connection.

26. The local quantum terminal of claim 23, wherein: The random number determined by the local quantum terminal is the same as the random number stored on the secure smart card.

27. A secure smart card comprising: A non-quantum channel interface, the non-quantum channel interface is used to receive a random number from a local quantum terminal through a non-quantum channel, wherein the random number is also stored in a memory of a remote quantum terminal; A memory, the memory being used to store the random number; and A processor is provided for performing a secure transaction between the secure smart card and the remote quantum terminal based on at least a portion of the random number stored in the secure smart card and at least a portion of the random number stored in the remote quantum terminal, wherein the portion of the random number is used as an encryption key for the encrypted transaction.

28. The secure smart card of claim 27, wherein: The secure smart card also includes a display for displaying the portion of the random number used to perform a secure transaction and a remaining portion of the random number stored on the secure smart card.

29. The secure smart card of claim 27, wherein: The secure smart card deletes the portion of the random number used to perform the secure transaction from a memory of the secure smart card.

Images