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Aelmans 8 Juniper Networks 9 May 5, 2020 11 Applications and Use Cases for the Quantum Internet 12 draft-wang-qirg-quantum-internet-use-cases-06 14 Abstract 16 The Quantum Internet has the potential to improve Internet 17 application functionality by incorporating quantum information 18 technology into the infrastructure of the overall Internet. In this 19 document, we provide an overview of some applications expected to be 20 used on the Quantum Internet, and then categorize them using various 21 classification schemes. Some general requirements for the Quantum 22 Internet are also discussed. The intent of this document is to 23 provide a common understanding and framework of applications and use 24 cases for the Quantum Internet. 26 Status of This Memo 28 This Internet-Draft is submitted in full conformance with the 29 provisions of BCP 78 and BCP 79. 31 Internet-Drafts are working documents of the Internet Engineering 32 Task Force (IETF). Note that other groups may also distribute 33 working documents as Internet-Drafts. The list of current Internet- 34 Drafts is at https://datatracker.ietf.org/drafts/current/. 36 Internet-Drafts are draft documents valid for a maximum of six months 37 and may be updated, replaced, or obsoleted by other documents at any 38 time. It is inappropriate to use Internet-Drafts as reference 39 material or to cite them other than as "work in progress." 41 This Internet-Draft will expire on November 6, 2020. 43 Copyright Notice 45 Copyright (c) 2020 IETF Trust and the persons identified as the 46 document authors. All rights reserved. 48 This document is subject to BCP 78 and the IETF Trust's Legal 49 Provisions Relating to IETF Documents 50 (https://trustee.ietf.org/license-info) in effect on the date of 51 publication of this document. Please review these documents 52 carefully, as they describe your rights and restrictions with respect 53 to this document. Code Components extracted from this document must 54 include Simplified BSD License text as described in Section 4.e of 55 the Trust Legal Provisions and are provided without warranty as 56 described in the Simplified BSD License. 58 Table of Contents 60 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 61 2. Conventions used in this document . . . . . . . . . . . . . . 3 62 3. Terms and Acronyms List . . . . . . . . . . . . . . . . . . . 3 63 4. Quantum Internet Applications . . . . . . . . . . . . . . . . 5 64 4.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 5 65 4.2. Classification by Application Usage . . . . . . . . . . . 5 66 4.2.1. Quantum Cryptography Applications . . . . . . . . . . 6 67 4.2.2. Quantum Sensor Applications . . . . . . . . . . . . . 6 68 4.2.3. Quantum Computing Applications . . . . . . . . . . . 6 69 4.3. Control vs Data Plane Classification . . . . . . . . . . 7 70 5. Selected Quantum Internet Use Cases . . . . . . . . . . . . . 7 71 5.1. Secure Communication Setup . . . . . . . . . . . . . . . 8 72 5.2. Distributed Quantum Computing . . . . . . . . . . . . . . 10 73 5.3. Secure Quantum Computing with Privacy Preservation . . . 12 74 6. General Requirements . . . . . . . . . . . . . . . . . . . . 14 75 7. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . 15 76 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 77 9. Security Considerations . . . . . . . . . . . . . . . . . . . 16 78 10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 16 79 11. Informative References . . . . . . . . . . . . . . . . . . . 16 80 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19 82 1. Introduction 84 The Classical Internet has been constantly growing since it first 85 became commercially popular in the early 1990's. It essentially 86 consists of a large number of end-nodes (e.g., laptops, smart phones, 87 network servers) connected by routers. The end-nodes may run 88 applications that provide service for the end-users such as 89 processing and transmission of voice, video or data. The connections 90 between the various nodes in the Internet include Digital Subscriber 91 Lines (DSLs), fiber optics, coax cable and wireless that include 92 Bluetooth, WiFi, cellular (e.g., 3G, 4G, 5G), and satellite, etc. 93 Bits are transmitted across the Classical Internet in packets. 95 Research and experimentation have picked up over the last few years 96 for developing a Quantum Internet [Wehner]. It is anticipated that 97 the Quantum Internet will provide intrinsic benefits such as better 98 end-to-end and network security. The Quantum Internet will also have 99 end-nodes, termed quantum end-nodes. Quantum end-nodes may be 100 connected by quantum repeaters/routers. These quantum end-nodes will 101 also run value-added applications which will be discussed later. 103 The connections between the various nodes in the Quantum Internet are 104 expected to be primarily fiber optics and free-space optics. 105 Photonic connections are particularly useful because light (photons) 106 is very suitable for physically encoding qubits. Unlike the 107 Classical Internet, qubits (and not classical bits or packets) are 108 expected to be transmitted across the Quantum Internet due to the 109 underlying physics. The Quantum Internet will operate according to 110 unique physical principles such as quantum superposition, 111 entanglement and teleportation [I-D.irtf-qirg-principles]. 113 The Quantum Internet is not anticipated to replace the Classical 114 Internet. For instance, Local Operations and Classical Communication 115 (LOCC) operations [Chitambar] even rely on classical communications. 116 Instead the Quantum Internet will run in conjunction with the 117 Classical Internet to form a new Hybrid Internet. The process of 118 integrating the Quantum Internet with the classical Internet is 119 similar to, but with more profound implications, as the process of 120 introducing any new communication and networking paradigm into the 121 existing Internet. The intent of this document is to provide a 122 common understanding and framework of applications and use cases for 123 the Quantum Internet. 125 2. Conventions used in this document 127 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 128 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 129 document are to be interpreted as described in [RFC2119]. 131 3. Terms and Acronyms List 133 This document assumes that the reader is familiar with the quantum 134 information technology related terms and concepts that are described 135 in [I-D.irtf-qirg-principles]. In addition, the following terms and 136 acronyms are defined here for clarity: 138 o Bit - Binary Digit (i.e., fundamental unit of information in a 139 classical computer). 141 o Classical Internet - The existing, deployed Internet (circa 2020) 142 where bits are transmitted in packets between nodes to convey 143 information. The Classical Internet supports applications which 144 may be enhanced by the Quantum Internet. For example, the end-to- 145 end security of a Classical Internet application may be improved 146 by secure communication setup using a quantum application. 148 o Hybrid Internet - The "new" or evolved Internet to be formed due 149 to a merger of the Classical Internet and the Quantum Internet. 151 o Local Operations and Classical Communication (LOCC) - A method 152 where: 1) local quantum operations (e.g., quantum measurement) are 153 performed at one quantum node A; 2) the quantum operation result 154 is sent to another quantum node B via classical communications; 3) 155 the quantum node B may also perform some local quantum operations 156 dependent on the received operation result from the quantum node 157 A. For example, LOCC can be used to transform entangled states 158 into other entangled states. 160 o Noisy Intermediate-Scale Quantum (NISQ) - NISQ was defined in 161 [Preskill] to represent a near-term era in quantum technology. 162 According to this definition, NISQ computers have two salient 163 features: (1) The size of NISQ computers range from 50 to a few 164 hundred qubits (i.e., intermediate-scale); and (2) Qubits in NISQ 165 computers have inherent errors and the control over them is 166 imperfect (i.e., noisy). 168 o Packet - Formatted unit of multiple related bits. The bits 169 contained in a packet may be classical bits, or the measured state 170 of qubits. 172 o Quantum End-node - An end-node hosts user applications and 173 interfaces with the rest of the Internet. Typically, an end-node 174 may serve in a client, server, or peer-to-peer role as part of the 175 application. If the end-node is part of the Quantum Network, it 176 must be able to generate/transmit and/or receive/process qubits. 177 A quantum end-node, if it has quantum memory and quantum computing 178 capabilities, can be regarded as a quantum computer. A quantum 179 end-node must also be able to interface to the Classical Internet 180 for control purposes and thus also be able to receive, process, 181 and transmit classical bits/packets. 183 o Quantum Computer (QC) - Compared to a quantum end-node, a QC has 184 more capabilities such as quantum memory and quantum circuits, 185 which are required for performing quantum computing tasks. 187 o Quantum Network - A new type of network enabled by quantum 188 information technology where qubits are transmitted between nodes 189 to convey information. (Note: qubits must be sent individually 190 and not in packets). The Quantum Network will use both quantum 191 channels, and classical channels provided by the Classical 192 Internet. 194 o Quantum Internet - A network of quantum networks. The Quantum 195 Internet will be merged into the Classical Internet to form a new 196 Hybrid Internet. The Quantum Internet may either improve 197 classical applications or may enable new quantum applications. 199 o Qubit - Quantum Bit (i.e., fundamental unit of information in a 200 quantum computer). It is similar to a classic bit in that the 201 state of a qubit is either "0" or "1" after it is measured and is 202 denoted as its basis state |0> or |1>. However, the qubit is 203 different than a classic bit in that the qubit is in a linear 204 combination of both states before it is measured and termed to be 205 in superposition. The Degrees of Freedom (DOF) of a photon (e.g., 206 polarization) or an electron (e.g., spin) can be used to encode a 207 qubit. 209 4. Quantum Internet Applications 211 4.1. Overview 213 The Quantum Internet is expected to be extremely beneficial for a 214 subset of existing and new applications. The expected applications 215 using Quantum Internet are still being developed as we are in the 216 formative stages of the Quantum Internet [Castelvecchi] [Wehner]. 217 However, an initial (and non-exhaustive) list of the applications to 218 be supported on the Quantum Internet can be identified and classified 219 using two different schemes. 221 4.2. Classification by Application Usage 223 Applications may also be grouped by the usage that they serve into a 224 tripartite classification. Specifically, applications may be 225 classified according to the following usages: 227 o Quantum cryptography applications - Refers to the use of quantum 228 information technology to ensure secure communications (e.g., 229 QKD). 231 o Quantum sensors applications - Refers to the use of quantum 232 information technology for supporting distributed sensors or 233 Internet of Things (IoT) devices (e.g., clock synchronization). 235 o Quantum computing applications - Refers to the use of quantum 236 information technology for supporting remote quantum computing 237 facilities (e.g., distributed quantum computing). 239 This is a useful classification scheme as it can be easily understood 240 by both a technical and non-technical audience. Following are some 241 more details. 243 4.2.1. Quantum Cryptography Applications 245 Examples of quantum cryptography applications include quantum-based 246 secure communication setup and fast Byzantine negotiation. 248 1. Secure communication setup - Refers to secure cryptographic key 249 distribution between two or more end-nodes. The most well-known 250 method is referred to as Quantum Key Distribution (QKD) [Renner]. 252 2. Fast Byzantine negotiation - Refers to a quantum network based 253 method for fast agreement in Byzantine negotiations [Fitzi]. 254 This can be used for the popular financial blockchain feature as 255 well as other distributed computing features which use Byzantine 256 negotiations. 258 4.2.2. Quantum Sensor Applications 260 The main example of a quantum sensor applications is currently 261 network clock synchronization. 263 1. Network clock synchronization - Refers to a world wide set of 264 atomic clocks connected by the Quantum Internet to achieve an 265 ultra precise clock signal [Komar]. 267 4.2.3. Quantum Computing Applications 269 Examples of quantum computing include distributed quantum computing 270 and secure quantum computing with privacy preservation. 272 1. Distributed quantum computing - Refers to a collection of remote 273 small capacity quantum computers (i.e., each supporting a few 274 qubits) that are connected and working together in a coordinated 275 fashion so as to simulate a virtual large capacity quantum 276 computer [Wehner]. 278 2. Secure quantum computing with privacy preservation - Refers to 279 private, or blind, quantum computation, which provides a way for 280 a client to delegate a computation task to one or more remote 281 quantum computers without disclosing the source data to be 282 computed over [Fitzsimons]. 284 4.3. Control vs Data Plane Classification 286 The majority of routers currently used in the Classical Internet 287 separate control plane functionality and data plane functionality 288 for, amongst other reasons, stability, capacity and security. In 289 order to classify applications for the Quantum Internet, a somewhat 290 similar distinction can be made. Specifically some applications can 291 be classified as being responsible for initiating sessions and 292 performing other control plane functionality. Other applications 293 carry application or user data and can be classified as data plane 294 functionality. 296 Some examples of what may be called control plane applications in the 297 Classical Internet are Domain Name Server (DNS), Session Information 298 Protocol (SIP), and Internet Control Message Protocol (ICMP). 299 Furthermore, examples of data plane applications are E-mail, web 300 browsing, and video streaming. Note that some applications may 301 require both control plane and data plane functionality. For 302 example, a Voice over IP (VoIP) application may use SIP to set up the 303 call and then transmit the VoIP user packets over the data plane to 304 the other party. 306 Similarly, nodes in the Quantum Internet applications may use the 307 same classification paradigm of control plane functionality versus 308 data plane functionality where: 310 o Control Plane - Network functions and processes that operate on 311 (1) control bits/packets or qubits (e.g., to setup up end-user 312 encryption); or (2) management bits/packets or qubits (e.g., to 313 configure nodes). 315 o Data Plane - Network functions and processes that operate on end- 316 user application bits/packets or qubits (e.g., voice, video, 317 data). Sometimes also referred to as the user plane. 319 5. Selected Quantum Internet Use Cases 321 The Quantum Internet will support a variety of applications and 322 deployment configurations. This section details a few key use cases 323 which illustrates the benefits of the Quantum Internet. In system 324 engineering, a use case is typically made up of a set of possible 325 sequences of interactions between nodes and users in a particular 326 environment and related to a particular goal. This will be the 327 definition that we use in this section. 329 5.1. Secure Communication Setup 331 In this scenario, two banks (i.e., Bank #1 and Bank #2) need to have 332 secure communications for transmitting important financial 333 transaction records (see Figure 1). For this purpose, they first 334 need to securely exchange a classic secret cryptographic key (i.e., a 335 sequence of classical bits), which is triggered by an end-user banker 336 at Bank #1. This results in a source quantum node A at Bank #1 to 337 securely send a classic secret key to a destination quantum node B at 338 Bank #2. This is referred to as a secure communication setup. Note 339 that the quantum node A and B may be either a bare-bone quantum end- 340 node or a full-fledged quantum computer. This use case shows that 341 the Quantum Internet can be leveraged to improve the security of 342 Classical Internet applications of which the financial application 343 shown in Figure 1 is an example. 345 One requirement for this secure communication setup process is that 346 it should not be vulnerable to any classical or quantum computing 347 attack. This can be realized using QKD [ETSI-QKD-Interfaces]. QKD 348 can securely establish a secret key between two quantum nodes, 349 without physically transmitting it through the network and thus 350 achieving the required security. QKD is the most mature feature of 351 the quantum information technology, and has been commercially 352 deployed in small-scale and short-distance deployments. More QKD use 353 cases have been described in ETSI GS QKD 002 [ETSI-QKD-UseCases]. 355 In general, QKD (e.g., [BB84]) without using entanglement works as 356 follows: 358 1. The source quantum node A (e.g. Alice) transforms the secret key 359 to qubits. Basically, for each classical bit in the secret key, 360 the source quantum node A randomly selects one quantum 361 computational basis and uses it to prepare/generate a qubit for 362 the classical bit. 364 2. The source quantum node A sends qubits to the destination quantum 365 node B (e.g. Bob) via quantum channel. 367 3. The destination quantum node receives qubits and measures them 368 based on its random quantum basis. 370 4. The destination node informs the source node of its random 371 quantum basis. 373 5. The source node informs the destination node which random quantum 374 basis is correct. 376 6. Both nodes discard any measurement bit under different quantum 377 basis and store all remaining bits as the secret key. 379 It is worth noting that: 381 1. There are some entanglement-based QKD protocols such as 382 [Treiber], which work differently than above steps. The 383 entanglement-based schemes, where entangled states are prepared 384 externally to Alice and Bob, are not normally considered 385 "prepare-and-measure" as defined in [Wehner]; other entanglement- 386 based schemes, where entanglement is generated within Alice can 387 still be considered "prepare-and-measure"; send-and-return 388 schemes can still be "prepare-and-measure", if the information 389 content, from which keys will be derived, is prepared within 390 Alice before being sent to Bob for measurement. 392 2. There are many enhanced QKD protocols based on [BB84]. For 393 example, a series of loopholes have been identified due to the 394 imperfections of measurement devices; there are several solutions 395 to take into account these attacks such as measurement-device- 396 independent QKD [ZhangPeiyu]. These enhanced QKD protocol can 397 work differently than the steps of BB84 protocol [BB84]. 399 3. For large-scale QKD, QKD Networks (QKDN) are required, which can 400 be regarded as a subset of a Quantum Internet. A QKDN may 401 consist of a QKD application layer, a QKD network layer, and a 402 QKD link layer [QinHao]. One or multiple trusted QKD relays 403 [ZhangQiang] may exist between the source quantum node A and the 404 destination quantum node B, which are connected by a QKDN. 405 Alternatively, a QKDN may rely on entanglement distribution and 406 entanglement-based QKD protocols; as a result, quantum-repeaters/ 407 routers instead of trusted QKD relays are needed for large-scale 408 QKD. 410 As a result, the Quantum Internet in Figure 1 contains quantum 411 channels. And in order to support secure communication setup 412 especially in large-scale deployment, it also requires entanglement 413 generation and entanglement distribution 414 [I-D.van-meter-qirg-quantum-connection-setup], quantum repeaters/ 415 routers, and/or trusted QKD relays. 417 +---------------+ 418 | End User | 419 |(e.g., Banking | 420 | Application) | 421 +---------------+ 422 ^ 423 | User Interface 424 | (e.g., GUI) 425 V 426 +-----------------+ /--------\ +-----------------+ 427 | |--->( Quantum )--->| | 428 | Source | ( Internet ) | Destination | 429 | Quantum | \--------/ | Quantum | 430 | Node A | | Node B | 431 | (e.g., Bank #1) | /--------\ | (e.g., Bank #2) | 432 | | ( Classical) | | 433 | |<-->( Internet )<-->| | 434 +-----------------+ \--------/ +-----------------+ 436 Figure 1: Secure Communication Setup 438 5.2. Distributed Quantum Computing 440 In this scenario, Noisy Intermediate-Scale Quantum (NISQ) computers 441 distributed in different locations are available for sharing. 442 According to the definition in [Preskill], a NISQ computer can only 443 realize a small number of qubits and has limited quantum error 444 correction. In order to gain higher computation power before fully- 445 fledged quantum computers become available, NISQ computers can be 446 connected via classic and quantum channels. This scenario is 447 referred to as distributed quantum computing [Caleffi] 448 [Cacciapuoti01] [Cacciapuoti02]. This use case reflects the vastly 449 increased computing power which quantum computers as a part of the 450 Quantum Internet can bring, in contrast to classical computers in the 451 Classical Internet. 453 As an example, scientists can leverage these connected NISQ computer 454 to solve highly complex scientific computation problems such as 455 analysis of chemical interactions for medical drug development (see 456 Figure 2). In this case, qubits will be transmitted among connected 457 quantum computers via quantum channels, while classic control 458 messages will be transmitted among them via classical channels for 459 coordination and control purpose. Qubits from one NISQ computer to 460 another NISQ computer are very sensitive and cannot be lost. For 461 this purpose, quantum teleportation can be leveraged to teleport 462 sensitive data qubits from one quantum computer A to another quantum 463 computer B. Note that Figure 2 does not cover measurement-based 464 distributed quantum computing, where quantum teleportation may not be 465 required. 467 Specifically, the following steps happen between A and B. In fact, 468 LOCC [Chitambar] operations are conducted at the quantum computer A 469 and B in order to achieve quantum teleportation as illustrated in 470 Figure 2. 472 1. The quantum computer A locally generates some sensitive data 473 qubits to be teleported to the quantum computer B. 475 2. A shared entanglement is established between the quantum computer 476 A and the quantum computer B (i.e., there are two entangled 477 qubits: |q1> at A and |q2> at B). 479 3. Then, the quantum computer A performs a Bell measurement of the 480 entangled qubit |q1> and the sensitive data qubit. 482 4. The result from this Bell measurement will be encoded in two 483 classical bits, which will be physically transmitted via a 484 classical channel to the quantum computer B. 486 5. Based on the received two classical bits, the quantum computer B 487 modifies the state of the entangled qubit |q2> in the way to 488 generate a new qubit identical to the sensitive data qubit at the 489 quantum computer A. 491 In Figure 2, the Quantum Internet contains quantum channels and 492 quantum repeaters/routers [I-D.irtf-qirg-principles]. This use case 493 needs to support entanglement generation in order to enable quantum 494 teleportation, entanglement distribution or quantum connection setup 495 [I-D.van-meter-qirg-quantum-connection-setup] in order to support 496 long-distance quantum teleportation. 498 +-----------------+ 499 | End-User | 500 |(e.g., Scientist)| 501 +-----------------+ 502 ^ 503 |User Interface (e.g. GUI) 504 | 505 +------------------+-------------------+ 506 | | 507 | | 508 V V 509 +----------------+ /--------\ +----------------+ 510 | |--->( Quantum )--->| | 511 | | ( Internet ) | | 512 | Quantum | \--------/ | Quantum | 513 | Computer A | | Computer B | 514 | (e.g., Site #1)| /--------\ | (e.g., Site #2)| 515 | | ( Classical) | | 516 | |<-->( Internet )<-->| | 517 +----------------+ \--------/ +----------------+ 519 Figure 2: Distributed Quantum Computing 521 5.3. Secure Quantum Computing with Privacy Preservation 523 Secure computation with privacy preservation refers to the scenario: 525 1. A client node with source data delegates the computation of the 526 source data to a remote computation node. 528 2. Furthermore, the client node does not want to disclose any source 529 data to the remote computation node and thus preserve the source 530 data privacy. 532 3. Note that there is no assumption or guarantee that the remote 533 computation node is a trusted entity from the source data privacy 534 perspective. 536 As an example illustrated in Figure 3, the client node could be a 537 virtual voice-controlled home assistant device like Amazon's Alexa 538 product. The remote computation node could be a quantum computer in 539 the cloud. A resident as an end-user uses voice to control the home 540 device. The home device captures voice-based commands from the end- 541 user. Then, the home device interfaces to a home quantum terminal 542 node (e.g., a home gateway), which interacts with the remote 543 computation node to perform computation over the captured voice-based 544 commands. The home quantum terminal could be either a bare-bone 545 quantum end-node or a full-fledged quantum computer. 547 In this particular case, there is no privacy concern since the source 548 data (i.e., captured voice-based commands) will not be sent to the 549 remote computation node which could be compromised. Protocols 550 [Fitzsimons] for delegated quantum computing or blind quantum 551 computation can be leveraged to realize secure delegated computation 552 and guarantee privacy preservation simultaneously. Using delegated 553 quantum computing protocols, the client node does not need send the 554 source data but qubits with some measurement instructions to the 555 remote computation node (e.g., a quantum computer). 557 After receiving qubits and measurement instructions, the remote 558 computation node performs the following actions: 560 1. It first performs certain quantum operations on received qubits 561 and measure them according to received measurement instructions 562 to generate computation results (in classic bits). 564 2. Then it sends the computation results back to the client node via 565 classical channel. 567 3. In this process, the source data is not disclosed to the remote 568 computation node and the privacy is preserved. 570 In Figure 3, the Quantum Internet contains quantum channels and 571 quantum repeaters/routers for long-distance qubits transmission 572 [I-D.irtf-qirg-principles]. 574 +----------------+ 575 | End-User | 576 |(e.g., Resident)| 577 +----------------+ 578 ^ 579 | User Interface 580 | (e.g., voice commands) 581 V 582 +----------------+ 583 | Home Device | 584 +----------------+ 585 ^ 586 | Classic 587 | Channel 588 V 589 +----------------+ /--------\ +----------------+ 590 | |--->( Quantum )--->| | 591 | Quantum | ( Internet ) | Remote | 592 | Terminal | \--------/ | Computation | 593 | Node | | Node | 594 | (e.g., Home | /--------\ | (e.g., QC | 595 | Gateway) | ( Classical) | in Cloud) | 596 | |<-->( Internet )<-->| | 597 +----------------+ \--------/ +----------------+ 599 Figure 3: Secure Computation with Privacy Preservation 601 6. General Requirements 603 Quantum Technologies are steadily evolving and improving. Therefore, 604 it is hard to predict the timeline and future milestones of quantum 605 technologies as pointed out in [Grumbling] for quantum computing. 606 Currently, a NISQ computer can achieve fifty to hundreds of qubits 607 with some error rate. In fact, the error rates of two-qubit quantum 608 gates have decreased nearly in half every 1.5 years (for trapped ion 609 gates) to 2 years (for superconducting gates). The error rate also 610 increases as the number of qubits increases. For example, a current 611 20-qubit machine has a total error rate which is close to the total 612 error rate of a 7-year old two-qubit machine [Grumbling]. 614 Although it is challenging to predict future progress of quantum 615 technologies, some general and functional requirements on the Quantum 616 Internet from the networking perspective, based on the above 617 applications and use cases, are identified as follows: 619 1. Methods for facilitating quantum applications to interact 620 efficiently with entanglement qubits are necessary in order for 621 them to trigger distribution of designated entangled qubits to 622 potentially any other quantum node residing in the Quantum 623 Internet. To accomplish this specific operations must be 624 performed on entangled qubits (e.g., entanglement swapping, 625 entanglement distillation). Quantum nodes may be quantum end- 626 nodes, quantum repeaters/routers, and/or quantum computers. 628 2. Quantum repeaters/routers should support robust and efficient 629 entanglement distribution in order to extend and establish 630 entanglement connection between two quantum nodes. For achieving 631 this, it is required to first generate an entangled pair on each 632 hop of the path between these two nodes. 634 3. Quantum end-nodes must send additional information on classical 635 channels to aid in transmission of qubits across quantum 636 repeaters/receivers. This is because qubits are transmitted 637 individually and do not have any associated packet overhead which 638 can help in transmission of the qubit. Any extra information to 639 aid in routing, identification, etc., of the qubit must be sent 640 via classical channels. 642 7. Conclusion 644 This document provides an overview of some expected applications for 645 the Quantum Internet, and then details selected use cases. The 646 applications are first grouped by their usage which is a natural and 647 easy to understand classification scheme. The applications are then 648 classified as either control plane or data plane functionality as 649 typical for the classical Internet. This set of applications may, of 650 course, naturally expand over time as the Quantum Internet matures. 651 Finally, some general requirements for the Quantum Internet are also 652 provided. 654 This document can also serve as an introductory text to persons 655 interested in learning about the practical uses of the Quantum 656 Internet. Finally, it is hoped that this document will help guide 657 further research and development of the specific Quantum Internet 658 functionality required to implement the applications and uses cases 659 described herein. To this end, a few key requirements for the 660 Quantum Internet are specified. 662 8. IANA Considerations 664 This document requests no IANA actions. 666 9. Security Considerations 668 This document does not define an architecture nor a specific protocol 669 for the Quantum Internet. It focuses on detailing use cases and 670 describing typical Quantum Internet applications. However, some 671 useful observations can be made regarding security as follows. 673 It has been clearly identified that once large-scale quantum 674 computing becomes reality it will be able to theoretically break many 675 of the public-key (i.e., asymmetric) cryptosystems currently in use 676 because of the exponential increase of computing power with quantum 677 computing. This would negatively affect many of the security 678 mechanisms currently in use on the classic Internet. This has given 679 strong impetus for starting development of new cryptographic systems 680 that are secure against quantum computing attacks [NISTIR8240]. 682 Paradoxically, development of a Quantum Internet will also mitigate 683 the threats posed by quantum computing attacks against public-key 684 cryptosystems. Specifically, the secure communication setup feature 685 of the Quantum Internet as described in Section 5.1 will be strongly 686 resistant to both classical and quantum computing attacks. 688 Finally, Section 5.3 provides a method to perform remote quantum 689 computing while preserving the privacy of the source data. 691 10. Acknowledgments 693 The authors want to thank Mathias VAN DEN BOSSCHE, Xavier de Foy, 694 Patrick Gelard, Wojciech Kozlowski, Rodney Van Meter, and Joseph 695 Touch for their very useful reviews and comments to the document. 697 11. Informative References 699 [BB84] Bennett, C. and G. Brassard, "Quantum Cryptography: Public 700 Key Distribution and Coin Tossing", 1984, 701 . 704 [Cacciapuoti01] 705 Cacciapuoti, A. and et. al., "Quantum Internet: Networking 706 Challenges in Distributed Quantum Computing", IEEE 707 Network, (Early Access), 2019, 708 . 710 [Cacciapuoti02] 711 Cacciapuoti, A. and et. al., "When Entanglement meets 712 Classical Communications: Quantum Teleportation for the 713 Quantum Internet", 2019, 714 . 716 [Caleffi] Caleffi, M. and et. al., "Quantum internet: From 717 Communication to Distributed Computing!", NANOCOM, ACM, 718 2018, . 720 [Castelvecchi] 721 Castelvecchi, D., "The Quantum Internet has arrived (and 722 it hasn't)", Nature 554, 289-292, 2018, 723 . 725 [Chitambar] 726 Chitambar, E. and et. al., "Everything You Always Wanted 727 to Know About LOCC (But Were Afraid to Ask)", 728 Communications in Mathematical Physics, Springer, 2014, 729 . 732 [ETSI-QKD-Interfaces] 733 ETSI GR QKD 003 V2.1.1, "Quantum Key Distribution (QKD); 734 Components and Internal Interfaces", 2018, 735 . 738 [ETSI-QKD-UseCases] 739 ETSI GR QKD 002 V1.1.1, "Quantum Key Distribution (QKD); 740 Use Cases", 2010, . 743 [Fitzi] Fitzi, M. and et. al., "A Quantum Solution to the 744 Byzantine Agreement Problem", 2001, 745 . 747 [Fitzsimons] 748 Fitzsimons, J., "Private Quantum Computation: An 749 Introduction to Blind Quantum Computing and Related 750 Protocols", 2017, 751 . 753 [Grumbling] 754 Grumbling, E. and M. Horowitz, "Quantum Computing: 755 Progress and Prospects", National Academies of Sciences, 756 Engineering, and Medicine, The National Academies Press, 757 2019, . 759 [I-D.dahlberg-ll-quantum] 760 Dahlberg, A., Skrzypczyk, M., and S. Wehner, "The Link 761 Layer service in a Quantum Internet", draft-dahlberg-ll- 762 quantum-03 (work in progress), October 2019. 764 [I-D.irtf-qirg-principles] 765 Kozlowski, W., Wehner, S., Meter, R., Rijsman, B., 766 Cacciapuoti, A., and M. Caleffi, "Architectural Principles 767 for a Quantum Internet", draft-irtf-qirg-principles-03 768 (work in progress), March 2020. 770 [I-D.van-meter-qirg-quantum-connection-setup] 771 Meter, R. and T. Matsuo, "Connection Setup in a Quantum 772 Network", draft-van-meter-qirg-quantum-connection-setup-01 773 (work in progress), September 2019. 775 [Komar] Komar, P. and et. al., "A Quantum Network of Clocks", 776 2013, . 778 [NISTIR8240] 779 Alagic, G. and et. al., "Status Report on the First Round 780 of the NIST Post-Quantum Cryptography Standardization 781 Process", NISTIR 8240, 2019, 782 . 785 [Preskill] 786 Preskill, J., "Quantum Computing in the NISQ Era and 787 Beyond", 2018, . 789 [QinHao] Qin, H., "Towards Large-Scale Quantum Key Distribution 790 Network and Its Applications", 2019, 791 . 794 [Renner] Renner, R., "Security of Quantum Key Distribution", 2006, 795 . 797 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 798 Requirement Levels", BCP 14, RFC 2119, 799 DOI 10.17487/RFC2119, March 1997, 800 . 802 [Treiber] Treiber, A. and et. al., "A Fully Automated Entanglement- 803 based Quantum Cyptography System for Telecom Fiber 804 Networks", New Journal of Physics, 11, 045013, 2009, 805 . 807 [Wehner] Wehner, S., Elkouss, D., and R. Hanson, "Quantum internet: 808 A vision for the road ahead", Science 362, 2018, 809 . 812 [ZhangPeiyu] 813 Zhang, P. and et. al., "Integrated Relay Server for 814 Measurement-Device-Independent Quantum Key Distribution", 815 2019, . 817 [ZhangQiang] 818 Zhang, Q., Hu, F., Chen, Y., Peng, C., and J. Pan, "Large 819 Scale Quantum Key Distribution: Challenges and Solutions", 820 Optical Express, OSA, 2018, 821 . 823 Authors' Addresses 825 Chonggang Wang 826 InterDigital Communications, LLC 827 1001 E Hector St 828 Conshohocken 19428 829 USA 831 Email: Chonggang.Wang@InterDigital.com 833 Akbar Rahman 834 InterDigital Communications, LLC 835 1000 Sherbrooke Street West 836 Montreal H3A 3G4 837 Canada 839 Email: rahmansakbar@yahoo.com 841 Ruidong Li 842 NICT 843 4-2-1 Nukui-Kitamachi 844 Koganei, Tokyo 184-8795 845 Japan 847 Email: lrd@nict.go.jp 848 Melchior Aelmans 849 Juniper Networks 850 Boeing Avenue 240 851 Schiphol-Rijk 1119 PZ 852 The Netherlands 854 Email: maelmans@juniper.net