ISO INTERNATIONAL STANDARD 23257 First edition 2022-02 Blockchain and distributed ledger technologies Reference architecture Technologies des chaines de blocs et technologies de registre distribué-Architecture de réference Reference number IS0 23257:2022(E) osi Copyright International Organization for Standardization IS02022 IS0 23257:2022(E) COPYRIGHT PROTECTED DOCUMENT @ IS02022 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on or ISo's member body in the country of the requester. ISO copyright office CP 401 · Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +4122 749 0111 Email: [email protected] Website: www.iso.org Published in Switzerland Copyightilleratinal Organization for Standardization @ IS0 2022 - All rights reserved IS0 23257:2022(E) Contents Page Foreword ..V Introduction. .. vi 1 Scope. 2 Normative references 3 Terms and definitions. 4 Symbols and abbreviated terms. ..4 5 Concepts .5 5.1 DLT and blockchain systems. .5 5.1.1 General .5 5.1.2 Blockchain DLT and non-blockchain DLT .6 5.2 Networking and Communications ..6 5.3 DLT platform .7 5.4 DLT system interfaces 5.5 .8 Consensus 5.6 Events 10 5.7 Integrity of ledger content. .10 5.8 Integrity and ledger management .11 5.9 Subchains and sidechains .12 5.10 DLT Applications. .12 5.11 DLT solutions... ..12 5.12 Smart contracts .13 5.12.1 General ..13 5.12.2 Smart contract execution on dedicated peers 14 5.12.3 Smart contract execution on arbitrary peers 5.13 Transactions and how they work. .. 14 5.14 Tokens, virtual and cryptocurrencies, coins, and associated concepts ..15 6 Cross-cutting aspects ..16 6.1 General. 6.2 Security .16 6.3 Identity. 6.4 Privacy 17 6.4.1 General .. 17 6.4.2 On-ledger PII storage. .. 18 6.4.3 Off-ledger PII storage.. ..19 6.5 DLT Governance 19 6.6 Management 20 6.7 Interoperability .21 6.8 Data flow... 24 7 Types of DLT systems. .25 8 Architectural considerations for DLT Systems .26 8.1 Characteristics and relationships. 26 8.2 Ledger technology.. 27 8.3 Ledger storage architecture. .27 8.4 Ledger control architecture 27 8.5 Ledger subsetting 27 8.6 Ledger permission. 27 9 Architectural views of reference architecture .27 9.1 General 27 9.1.1 Five architectural views 27 9.1.2 Notation of diagrams... .28 9.2 Userview .29 CopyrightInternational OorghzSPi222araizAJ1 rights reserved iii IS0 23257:2022(E) 9.2.1 General. 29 9.2.2 DLT users. .30 9.2.3 DLTadministrators 30 9.2.4 DLT providers. 31 9.2.5 DLT developers. 32 9.2.6 DLT governors. 33 9.2.7 DLT auditors. 33 9.3 Functional view 34 9.3.1 Functional categorization framework 34 9.3.2 Non-DLT systems 35 9.3.3 User layer 35 9.3.4 APIlayer 35 9.3.5 DLT platform layer. 36 9.3.6 Infrastructure layer. 38 9.3.7 Cross-layer functions 39 9.4 System view 45 9.4.1 General 45 9.4.2 DLT Nodes. 46 9.4.3 Application systems 46 9.4.4 Non-DLT systems 46 9.4.5 Other DLT systems. 46 9.4.6 Cross-layer functions. 46 Annex A (informative) Consideration of tokens, virtual and cryptocurrencies, coins, and associated concepts. 47 Annex B (informative) Ledger implementation examples .50 Bibliography 51 @IS02022-Allrightsreserved IS0 23257:2022(E) Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards bodies (IsO member bodies). The work of preparing International Standards is normally carried out throughIsotechnicalcommittees.Eachmemberbodyinterestedinasubjectforwhichatechnical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with Iso, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures used to develop this document a