NIST Special Publication 1900-202 Cyber-Physical Systems and Internet of Things Christopher Greer Martin Burns David Wollman Edward Griffor This publication is available free of charge from: https://doi.org/10.6028/NIST.SP.1900-202 C Y B E R - P H Y S I C A L S Y S T E M S NIST Special Publication 1900-202 Cyber-Physical Systems and Internet of Things Christopher Greer Martin Burns David Wollman Edward Griffor Smart Grid and Cyber-Physical Systems Program Office Engineering Laboratory This publication is available free of charge from: https://doi.org/10.6028/NIST.SP.1900-202 March 2019 C Y B E R - P H Y S I C A L S Y S T E M S U.S. Department of Commerce Wilbur L. Ross Jr., Secretary National Institute of Standards and Technology Walter Copan, NIST Director and Undersecretary of Commerce for Standards and Technology National Institute of Standards and Technology (NIST) Special Publication 1900-202 61 pages (March 2019) Publications in the SP 1900 subseries present information of interest to the cyber-physical systems (CPS) community, where CPS are defined as smart systems that include engineered interacting networks of physical and computational components. The series was established in 2016 by the Smart Grid and Cyber-Physical Systems Program Office of the NIST Engineering Laboratory to provide a separate identity for CPS and Internet of Things publications, including those concerned with the foundations of CPS, CPS testbed science, and CPS applications, e.g., smart grid, smart cities and intelligent transportation. The series reports on research, guidelines, and outreach efforts in CPS, and its collaborative activities with industry, government, and academic organizations. Certain commercial entities, equipment, or materials may be identified in this document to describe a concept adequately. Such identification is not intended to imply recommendation or endorsement by the by NIST, nor is it intended to imply that these entities, materials, or equipment are necessarily the best available for the purpose. All registered trademarks or trademarks belong to their respective organizations. National Institute of Standards and Technology Special Publication 1900-202 Natl. Inst. Stand. Technol. Spec. Publ. 1900-202, 61 pages (March 2019) CODEN: NSPUE2 This publication is available free of charge from: https://doi.org/10.6028/NIST.SP.1900-202 NIST Special Publication 1900-202 Cyber-Physical Systems and Internet of Things Revision Tracking Version Date Editor Changes 1.0 March 2019 Christopher First Release Greer This publication is available free of charge from: https://doi.org/10.6028/NIST.SP 1900 - 202 i NIST Special Publication 1900-202 Cyber-Physical Systems and Internet of Things Table of Contents Table of Contents .......................................................................................................... ii Table of Figures ........................................................................................................... iii Table of Tables ............................................................................................................. iv Executive Summary ........................................................................................................ v 1 Introduction .............................................................................................................. 1 This publication is available free of charge from: 2 Cyber-Physical Systems History and Definitions ......................................................... 1 2.1 History and Trends ...................................................................................................... 1 2.2 Examples of CPS Definitions ........................................................................................ 2 2.3 Analysis of CPS Definitions .......................................................................................... 3 3 Internet of Things History and Definition ................................................................... 5 3.1 History and Trends ...................................................................................................... 5 3.2 Examples of Definitions ............................................................................................... 6 3.3 Analysis of IoT Definitions ........................................................................................... 7 4 Comparison of CPS and IoT ...................................................................................... 10 4.1 Distinct Origins .......................................................................................................... 10 4.2 Description of Previously-Proposed CPS/IoT Overlap Models .................................. 10 https://doi.org/10.6028/NIST.SP 4.3 Analysis of Overlap Models ....................................................................................... 13 5 Significance of Convergence .................................................................................... 17 6 Unified Perspective ................................................................................................. 19 6.1 Components Model: Linked Logical and Physical Elements ..................................... 19 6.2 Interactions Model: Linked State Transitions ........................................................... 20 6.3 Components Categories ............................................................................................ 21 6.4 Component Capabilities ............................................................................................ 24 6.5 CPS/IoT Criteria ......................................................................................................... 24 1900 7 Implications for Research, Development, and Standards ......................................... 25 - 202 7.1 Design Assurance....................................................................................................... 26 7.2 Cyber-Physical Security ............................................................................................. 27 8 Conclusions ............................................................................................................. 28 9 References .............................................................................................................. 30 10 Appendix A – Examples of CPS Definitions ............................................................... 38 11 Appendix B – Examples of IoT Definitions ................................................................ 44 12 Appendix C – Relationship between IoT and CPS ..................................................... 50 Page ii NIST Special Publication 1900-202 Cyber-Physical Systems and Internet of Things Table of Figures Figure 1. CPS Article Trends .............................................................................................. 2 Figure 2. CPS Query Trends .............................................................................................. 2 Figure 3. CPS Word Frequency .......................................................................................... 3 This publication is available free of charge from: Figure 4. IoT Article Trends ............................................................................................... 6 Figure 5. IoT Query Trends ............................................................................................... 6 Figure 6. IoT Word Frequency........................................................................................... 7 Figure 7A. Partial Overlap .............................................................................................. 11 Figure 7B. Equivalence ................................................................................................... 11 Figure 7C. CPS as a Subset .............................................................................................. 11 Figure 7D. IoT as a Subset............................................................................................... 11 Figure 8A. Components Model ....................................................................................... 19 Figure 8B. Interactions Model ........................................................................................ 20 https://doi.org/10.6028/NIST.SP 1900 - 202 Page iii NIST Special Publication 1900-202 Cyber-Physical Systems and Internet of Things Table of Tables Table 1. CPS Word Count .................................................................................................. 2 Table 2. IoT Word Count .................................................................................................. 6 This publication is available free of charge from: https://doi.org/10.6028/NIST.SP 1900 - 202 Page iv NIST Special Publication 1900-202 Cyber-Physical Systems and Internet of Things Executive Summary The phrases “cyber-physical systems,” or “CPS,” and “Internet of Things,” or “IoT,” have distinct origins but overlapping definitions, with both referring to trends in integrating digital capabilities, including network connectivity and computational capability, with physical devices and systems. Examples range from intelligent vehicles to advanced manufacturing systems, in sectors as diverse as energy, agriculture, smart cities, and beyond. This publication is available free of charge from: There has historically been uncertainty about the relationship between CPS and IoT, which has hindered close interaction and communication across the respective communities.