Methodology
How the edition was made: methods, the model card, the evidence cut and its age, the acceptance record and the glossary.
Contents
- ·Edition home
- ·Executive summary
- 1Digital systems fail together
- 2Key findings
- 3Systems and sectors at baseline
- 4Risks and capability
- 5Shared provider failure that overlaps a power or network loss
- 6Readings from the other desks
- 7The 2027 agenda
- 8Systems in depth
- AMethodology
- A.1 Methods
- A.2 Model card, Digital Public Infrastructure Model v0
- A.3 The baseline evidence cut
- A.4 Evidence age and coverage
- A.5 Evidence cards, two anchor sources
- A.6 Publication acceptance record
- A.7 Status words
- A.8 How the edition is made, released and corrected
- A.9 Glossary and abbreviations
- A.10 Technical annex
- BData appendix
- CReferences and record
- ·Complete edition, for print
A.1Methods
The global baseline uses published values and four simple derivations. Each is shown in full so that any reader can reproduce it.
| No. | Derivation | Calculation | Result |
|---|---|---|---|
| (1) | ENISA incidents per month in the period | 4,875 ÷ 12 | ≈ 406 |
| (2) | Growth in UK nationally significant incidents | 204 ÷ 89 | ≈ 2.3 times |
| (3) | Duration of the AWS event, first impact to end | 11:48 PM to 2:20 PM PDT | 14 h 32 min, ≈ 14.5 h |
| (4) | Duration of the Cloudflare event, first impact to full resolution | 11:20 to 17:06 UTC | 5 h 46 min, ≈ 5.8 h |
| Strength | Definition |
|---|---|
| STRONG | a disruption in the source system has historically changed the target system’s service or output within one season, in more than one region |
| MODERATE | an effect is documented but buffered or slower |
| WEAK | an effect is plausible but not documented at global scale |
| Label | Rule |
|---|---|
| Reported | value as issued by its source, with year |
| Inferred | reasoned from cited evidence; never a measurement |
| Estimated | Nexus analytical value with stated method |
| Scenario | conditional on stated assumptions |
| Expert input | structured editorial judgement awaiting evidence |
A.2Model card, Digital Public Infrastructure Model v0
- Model ID
- MDL-SR10-DPI · v0.1
- Purpose
- represent digital public infrastructure as a dependent stack and the mechanisms by which failures spread between identity, payments, data exchange, cloud, networks and the services that rely on them
- Family
- graph-based system of systems
- Inputs
- the cited sources of this edition; no proprietary data
- Method
- expert-specified coupling strengths (STRONG · MODERATE · WEAK) from assessments and analogue events
- Validation
- none yet, first validation against federation evidence in 2027
- Uncertainty
- qualitative; strengths are hypotheses, not measurements
- Domain of validity
- global scale; not for asset-, site- or country-level use
- Reproducibility
- strength table and sources published in this edition
20couplings
typed in v0
1strong
documented within one season
3moderate
documented, buffered
16weak
plausible, undocumented
A.3The baseline evidence cut
Every Nexus edition is published from a frozen evidence cut. The global baseline cut is documentary: it pins the exact edition of every source cited. Federation cuts begin with the first national Foundry cuts in 2027.
- Cut ID
- DC-STRATEGIC-DPI-GLOBAL-2026-B0
- Type
- baseline documentary cut
- Resolution policy
- pinned · as of 30 September 2026
- Sources pinned
- 43 cited sources, each at the edition and access date in the references
- Model runs
- none at baseline, analytical values are stated with their method
- Digest
- computed at freeze and recorded in the publication record
- Supersedes
- nothing, first cut of the series
- Superseded by
- the 2027 digital public infrastructure annual cut
Lineage
- 01
source edition
- 02
pinned citation
- 03
finding
- 04
page
- 05
publication record
| Element | Baseline 2026 | 2027 global annual |
|---|---|---|
| Sources | cited global publications, pinned by edition | national, regional and sector cuts through one graph |
| Analysis | stated methods and editorial estimates | typed analysis specifications |
| Models | Digital Public Infrastructure Model v0 specification | model runs with receipts |
| Findings | twelve baseline findings | findings re-bound to federation evidence |
| Review | five passes scheduled | five passes on the exact digest |
A.4Evidence age and coverage
A 2026 global edition rests on evidence observed in many different years. This page shows each time base, so that no single year label hides older evidence.
| Indicator | Observed | Released | Cadence | Next release |
|---|---|---|---|---|
| Software outage | 2024 | Jul 2024 | one-off | none scheduled |
| Cloud event | Oct 2025 | Oct 2025 | per event | next provider report |
| Edge event | Nov 2025 | Nov 2025 | per event | next provider report |
| Cyber advisories | 2024 to 2025 | Feb 2024 · Aug 2025 | per event | next joint advisory |
| EU incident counts | Jul 2024 to Jun 2025 | Oct 2025 · v1.3 Sep 2026 | annual | next ENISA report |
| UK incident counts | Sep 2024 to Aug 2025 | Oct 2025 | annual | next NCSC review |
| Connectivity | 2025 | Nov 2025 | annual | next ITU release |
| Account ownership | 2025 | 2025 | triennial | next Findex |
| Payment volumes | Oct 2025 · Dec 2025 | Nov 2025 · Dec 2025 | monthly | next monthly release |
| Event loss estimate | 2025 | Oct 2025 | per event | may be revised |
| System | Coverage | Thinnest dimension |
|---|---|---|
| Software and cloud | PARTIAL | cross-provider dependency |
| Networks | PARTIAL | cross-operator dependency |
| Identity | THIN | national system coverage |
| Payments | PARTIAL | outage and fraud data |
| Data exchange | THIN | coverage beyond one country |
| Cyber threat | PARTIAL | operator-level data |
| Access and inclusion | GOOD | identity coverage by country |
| Event losses | THIN | common loss basis |
| Field | Source that would fill it | Blocker |
|---|---|---|
| Which public services depend on which shared digital rails, at national scale | operators, regulators and national statistics offices | security-sensitive and not published on a common basis |
| Restoration times for identity and payment services after major outages | operator and regulator reports | not retrieved; no consolidated series |
| ENISA sector breakdown and top threats | ENISA Threat Landscape 2025 full report1 | the publication page was read; the PDF was not opened and the page notes corrected figures in version 1.3 |
| Share of cloud and edge traffic by provider and region | providers and network measurement bodies | not retrieved |
| Outage and fraud data for national payment rails | central banks and payment bodies | only volume reports were read; no incident series found |
| Official statistics pages for UPI and Pix | NPCI and Banco Central do Brasil1314 | official statistics pages returned no figures; values come from press reports of the official data |
| People without official identity from the dataset itself | World Bank ID4D Global Dataset26 | the repository returned an access error; the figure comes from search summaries |
| Number of individuals affected by the 2024 health claims platform breach | US Department of Health and Human Services breach portal28 | portal not opened; a later higher figure appears in a single press report only |
| Full text of the G20 declaration on digital public infrastructure | G20 New Delhi Leaders Declaration27 | not opened; wording taken from press coverage |
| National inventories of identity, payment and data-exchange systems | national authorities | no common register found |
| Common loss basis for cyber events | insurers and event classifiers | one classified event read; no series |
| Capability rungs beyond restoration | operators, regulators, ministries | not reviewed |
A.5Evidence cards, two anchor sources
Issued by the cloud provider. One-off. Role: binds DAT-002. Coverage: one region and services that rely on it. Times are stated in Pacific time.
EVD-SR10-001
AWS post-event summary on the October 2025 disruption4
Issued by the EU Agency for Cybersecurity. Annual. Role: binds CYB-007. Reporting period 1 July 2024 to 30 June 2025; the page notes corrections in version 1.3.
EVD-SR10-002
ENISA Threat Landscape 20251
| Dimension | EVD-SR10-001 | EVD-SR10-002 |
|---|---|---|
| Completeness | event-specific; customer impact varied within the window | incidents analysed; sector split not read |
| Timeliness | published days after the event | about 3 months after the period |
| Revision | single summary | version 1.3 corrected figures |
| Method transparency | root cause and timeline stated | threat-centric method stated |
| External validation | provider statement | agency review |
Evidence cards to follow in 2027
A.6Publication acceptance record
Editorial self-check at evidence close. Every applicable item carries a disposition; the remaining items are review, approval and deposit.
| Group | Area | Items | Pass | N/A | Pending |
|---|---|---|---|---|---|
| D1 | Identity and scope | 8 | 8 | 0 | 0 |
| D2 | Source and data | 12 | 9 | 1 | 2 |
| D3 | Analysis and models | 12 | 3 | 8 | 1 |
| D4 | Findings and claims | 9 | 8 | 0 | 1 |
| D5 | Figures, tables, maps | 10 | 6 | 2 | 2 |
| D6 | Editorial and citations | 10 | 8 | 0 | 2 |
| D7 | Review and approval | 13 | 0 | 0 | 13 |
| D8 | Artefact and design | 12 | 7 | 0 | 5 |
| D9 | Registry and release | 9 | 0 | 0 | 9 |
Publication gate
- Conditions met
- 14 of 23 at evidence close
- Blocking problems
- none recorded
- Open conditions
- reviews, approval of the exact digest, deposit, registry pointer
Not applicable at baseline
- Model runs
- first runs in Q1 2027
- Maps
- plates in Q2 2027
- Waivers
- none
A.7Status words
| Status | What it means |
|---|---|
| Observed | Measured directly and published by the source. |
| Reported | Published statistics of an official or institutional source. |
| Declared | Stated by the body concerned; not independently measured. |
| Estimated | A Nexus estimate from cited evidence, with its method in Annex A. |
| Modelled | Produced by a stated model from cited inputs. |
| Inferred | Reasoned from cited evidence; not measured. |
| Forecast | A projection by the cited source. |
| Simulated | A simulation result under stated assumptions. |
| Scenario | A conditional statement under stated assumptions; never a prediction. |
| Expert input | Expert judgement, recorded with its basis. |
| Candidate | Proposed for a later edition; not yet evidence. |
| Evidence-quality levels (EQL 1 to 5) grade the source behind a value; they are not a score of the subject. | |
A.8How the edition is made, released and corrected
Every edition is built from a sealed evidence cut, reviewed under three keys, signed and deposited before any site shows it as published; corrections go to Nexus Standards as change proposals and feed the next cut.
| Step | What happens | Source |
|---|---|---|
| 01 Evidence arrives from the pillars | Foundry seals observations and indicator series, Universe hands over after-action and scenario findings, and contributions are screened at every gateway, including this site’s. | |
| 02 The cut is sealed | On the cut date the evidence is pinned under one identifier, so anyone can rebuild the edition from exactly what it was built on. | |
| 03 The edition is assembled | The edition is drafted from its template and content pack. Agents may draft; they never publish and never decide. | |
| 04 The keys turn | At the publisher of record the truth key comes first: every value is checked against its source or stated method before the meaning and capital keys turn. No edition moves on until every key has been turned by a named steward. | |
| 05 The gate opens | A named approver releases one exact digest of the edition; any change after this point is a new version, never a silent edit. | |
| 06 Signed and deposited | The PDF, the web edition and the data bundle are signed together with a manifest and an RO-Crate description, and deposited on Zenodo with a concept and a version DOI. | |
| 07 Published on its desk’s site | Only then does the edition show as published on its desk’s Reports site, and the Collection lists it as a part. | |
| 08 Corrections go to Standards | Method and correction findings go to Nexus Standards as change proposals; citations, corrections and new contributions feed the next evidence cut. |
A teaching model of the process, not a forecast and not a record of any run; dates and counts on this page come from the programme record. Sources: Reports governance at GCRI Canada (2026); Zenodo, repository of record for Reports deposits (2026).
Lifecycle, one state at a time: Draft, Computed, Evidence bound, Reviewed, Approved for release, Published, Corrected, Superseded. This edition is a draft.
A.9Glossary and abbreviations
| Term | Meaning |
|---|---|
| Baseline Edition | the inaugural annual edition that fixes the reference state for the series |
| WEFH+B | water, energy, food, health and biodiversity, the national nexus core |
| Coupling | a typed dependency through which one system transmits to another |
| Protection gap | the share of losses not covered by insurance |
| Capability ladder | LISTED → EXISTS → ADEQUATE → TESTED → DEMONSTRATED |
| EQL | evidence-quality level, 1–5 |
| Evidence cut | a frozen resolution of exact sources and versions |
| NNC · NLC · NWG | National Nexus Consortium · National Leadership Council · National Working Groups |
| Abbreviation | Expansion |
|---|---|
| CISA | US Cybersecurity and Infrastructure Security Agency |
| CMC | Cyber Monitoring Centre |
| CSF | Cybersecurity Framework |
| DNS | Domain Name System |
| DORA | Digital Operational Resilience Act |
| DPI | digital public infrastructure |
| ENISA | European Union Agency for Cybersecurity |
| ITU | International Telecommunication Union |
| NCSC | UK National Cyber Security Centre |
| NIS2 | second Network and Information Security Directive |
| NPCI | National Payments Corporation of India |
| UPI | Unified Payments Interface |
A.10Technical annex
| Item | Annex | Contents | Status |
|---|---|---|---|
| A.1 | Indicator definitions | the global indicator set, with units and sources | IN THIS EDITION |
| A.2 | Coupling strengths | the twenty-cell matrix and its rationale | IN THIS EDITION |
| A.3 | Scenario specification | SCN-SR10-DPI-01 assumptions and signposts | IN THIS EDITION |
| A.4 | Capability placements | rung evidence for fifteen functions | IN THIS EDITION |
| A.5 | Model diagnostics | first runs and validation | 2027 |
| A.6 | Sensitivity analyses | influence of coupling strengths | 2027 |
| A.7 | Regional notes | regional digital cards | WITH REGIONAL EDITIONS |
| A.8 | Review statements | pass-by-pass review record | AT RELEASE |
A.1 · indicator definition: nationally significant incident
- Construct
- a cyber incident that the national agency classes in the top three categories of its classification model
- Unit
- incidents per year
- Method
- incident management data of one national agency
- Source
- NCSC Annual Review8
- Uncertainty
- classification and reporting practice change over time
- Known limits
- one country; not comparable with counts from other agencies
Notes
Numbers are the edition’s reference numbers, so a note reads the same in every chapter. The full list, with every source and its licence, is in Annex C. Annex C, references
- 1ENISA (ed.), ENISA Threat Landscape 2025 (publication page; period 1 July 2024 to 30 June 2025; published 1 October 2025; 4,875 incidents; version 1.3 of 22 September 2026). European Union Agency for Cybersecurity, Athens. Observation year 2025. Accessed 2026-11-03.back
- 13Entrackr, UPI hits all-time high of 20.7 bn transactions in October (press report of NPCI data: 20.7 billion transactions, Rs 27.28 lakh crore, up 25% and 16% year on year); the NPCI statistics page returned no figures. Observation year 2025. Accessed 2026-11-03.back
- 14Agência Brasil, Pix bate recorde e supera 313 milhões de transações em um dia (press report of Banco Central do Brasil data: about 313.3 million transactions and R$ 179.9 billion on 5 December 2025; previous record 297.4 million on 28 November 2025); the central bank statistics page returned no figures. Observation year 2025. Accessed 2026-11-03.back
- 26UNVERIFIED, not opened: World Bank (ed.), ID4D Global Dataset 2021, Volume 1: Global ID Coverage Estimates (just under 850 million people without official proof of identity in 2021; about half children; 194 countries), taken from search-result summaries; the repository returned an access error. World Bank, Washington, 2022. Observation year 2021. Accessed 2026-11-03.back
- 28UNVERIFIED, not opened: US Department of Health and Human Services Office for Civil Rights, Change Healthcare cybersecurity incident (about 100 million notices sent by October 2024), taken from search-result summaries of HHS statements; a later figure of 192.7 million appears in one press report and is not used. Observation year 2024. Accessed 2026-11-03.back
- 27UNVERIFIED, not opened: G20, New Delhi Leaders’ Declaration, 9 to 10 September 2023 (welcomed the G20 Framework for Systems of Digital Public Infrastructure and a global repository of digital public infrastructure), taken from press coverage of the declaration. Observation year 2023. Accessed 2026-11-03.back
- 4Amazon Web Services (ed.), Summary of the Amazon DynamoDB service disruption in the Northern Virginia (US-EAST-1) Region, 19 to 20 October 2025 (post-event summary). Amazon Web Services, Seattle. Observation year 2025. Accessed 2026-11-03.back
- 6CISA, NSA, FBI and partner agencies (eds.), Joint cybersecurity advisory AA24-038A on state-sponsored actor persistent access to critical infrastructure networks, 7 February 2024 (page text read to character 100,000 of 132,303). CISA, Arlington. Observation year 2024. Accessed 2026-11-03.back
- 7CISA and partner agencies (eds.), Joint cybersecurity advisory AA25-239A on state-sponsored actor compromise of networks worldwide, 27 August 2025 (revised 3 September 2025). CISA, Arlington. Observation year 2025. Accessed 2026-11-03.back
- 8National Cyber Security Centre (ed.), NCSC Annual Review 2025, incident management chapter and news item (period 1 September 2024 to 31 August 2025; 429 incidents; 204 nationally significant; 18 highly significant). NCSC, London. Observation year 2025. Accessed 2026-11-03.back