Supply Chain Risk Management

Digital Proximity: The Metric We Had to Invent to Assess Risk

Rating vendors is not enough. This patent-pending measurement of supplier connection depth is changing how organizations prioritize supply chain risk.

Digital Proximity model showing how supplier connection depth affects third-party riskThingsRecon company logo with stylized wing icon on a dark blue background.

Digital Proximity measures connection depth between suppliers and critical systems, helping teams prioritize third-party risk by potential blast radius rather than supplier posture alone.

When we started building ThingsRecon, one of the first problems we hit was deceptively simple: given a list of suppliers connected to an organization's digital environment, how do you decide which ones matter most?

The obvious answer (rank them by their security score) turned out to be the wrong answer. A supplier with a mediocre security score but a single, low-traffic DNS reference poses a fundamentally different risk than a supplier with an excellent score whose JavaScript is executing in the browser of every user on your primary e-commerce platform. The score does not capture the relationship. And the relationship is what determines the blast radius.

We needed a way to measure not just the supplier's security posture, but the depth and nature of their digital relationship with the client. We called the resulting metric Digital Proximity and filed a patent request. It is, as far as we know, the first measure of its kind.

What is Digital Proximity?

Digital proximity is a composite score that reflects how embedded a supplier is in an organization's digital surface. It is calculated from the volume, variety, and criticality of digital signals connecting the organization to the supplier.

A signal can be almost anything:  

  • A DNS record pointing to a supplier's infrastructure
  • An HTTP header referencing a supplier's service
  • A JavaScript library loaded from a supplier's CDN
  • An API endpoint called from an organization's application
  • A certificate issued by a supplier's PKI
  • A tracking pixel embedded in a page

Each signal type carries a different weight. A script executing in the browser of your users is a more significant connection than a DNS TXT record used for email verification. The proximity score reflects these differences.

The resulting number tells you how much of a given supplier's infrastructure is present in your digital environment, and, by extension, how large the impact would be if that supplier's infrastructure were compromised or unavailable.

How Digital Proximity Changes Risk Prioritization

Most supply chain risk frameworks prioritize suppliers based on contract value, data classification, or regulatory criticality, all of which are useful dimensions.  

Digital proximity adds a fourth dimension that the others cannot capture: actual digital exposure.

Consider a scenario where a mid-tier SaaS platform, perhaps a learning management system, has been embedded across an organization's intranet applications. It’s not a tier-one supplier by contract value. It processes no personally identifiable data, and it’s not in scope for the organization's most rigorous annual assessment. But its scripts execute on authenticated internal pages. Its CDN serves assets to a significant proportion of the employee base. Its proximity score is high.

If that supplier's CDN is compromised — as has happened multiple times in recent years through supply chain attacks targeting JavaScript library providers — the blast radius is significant. Proximity scoring surfaces that risk. Contract-based tiering does not.

In practice, we regularly find that the highest-proximity suppliers are not the ones with the highest scrutiny in the TPRM program. They are the ones that have grown their digital footprint gradually through product integrations, developer choices, and expanding service scopes, without triggering a formal reassessment. Their risk has grown faster than the program.

The Technical Foundation for Digital Proximity

Calculating digital proximity requires solving two hard problems simultaneously: comprehensive discovery and reliable connection mapping.

Comprehensive discovery means finding all the digital signals, not just the obvious ones. Most existing tools look at DNS records and HTTP headers. ThingsRecon goes deeper, crawling the logic inside JavaScript files to find API calls and external references, following script chains to identify CDN dependencies, tracking header sequences to map authentication flows.  

We use geolocated scanning nodes in over 40 regions because digital infrastructure behaves differently from different locations — some assets are only visible from certain geographies, and geo-fencing can hide significant portions of a supplier's surface from single-location scans.

Connection mapping means understanding which signals relate to which suppliers and which parts of those suppliers' infrastructure. A single large platform vendor may have dozens of domains and IP ranges serving different services. We build and maintain supplier ecosystem maps that allow us to attribute connections accurately, so when we say Microsoft's proximity score is high, we can show you exactly which Microsoft services and infrastructure components are creating that score.

The combination of comprehensive discovery and accurate attribution is what makes the proximity score meaningful. Without it, you have a list of domain names. With it, you have an evidence-based map of your real digital supply chain.

Proximity as a Vendor Risk Management Conversation Starter

One of the most valuable uses of proximity scoring we have seen in practice is as a conversation starter with suppliers. When you go to a high-proximity supplier with evidence that a specific component — not their entire estate, but the specific API endpoint or script tag that connects to your environment — has a hygiene issue, the conversation changes character entirely.

Instead of 'your annual questionnaire says you patch within 30 days, can you confirm?' you have: 'this component, which executes in our users' browsers, is running a version with three known vulnerabilities, the oldest of which is 18 months old, can you give us a remediation timeline?' That is a conversation grounded in evidence that cannot be dismissed with a policy statement.

This is the practical payoff of moving from generic scores to contextual signals: it makes remediation conversations possible and productive, rather than bureaucratic exercises in paper compliance.

What Comes Next

Digital proximity is one component of a broader approach to supply chain intelligence that we are continuing to develop. The next layer is fourth-party proximity: mapping not just the suppliers you are connected to, but the infrastructure those suppliers depend on, and scoring the indirect exposure that creates.

We are also developing proximity trending: tracking how each supplier's proximity score changes over time, so that organizations can identify which supplier relationships are growing in digital depth without corresponding growth in risk scrutiny. In most organizations, that list is longer than anyone expects.

The goal, ultimately, is to replace the static vendor register with a living map: a continuously updated, evidence-based picture of the real digital ecosystem and the risk it carries. Digital proximity is the measurement that makes that map meaningful.

If you’d like to see it applied to your digital ecosystem, request a free Proximity Snapshot.

Frequently Asked Questions

What is supply chain blast-radius mapping?

Supply chain blast-radius mapping identifies which systems, services, business processes and downstream dependencies could be affected when a supplier, technology or shared provider is compromised or unavailable. It connects an incident to the organisation’s actual digital relationships, allowing responders to move beyond a vendor name and determine where exposure exists. A useful map includes direct and indirect suppliers, connected assets, critical services, shared infrastructure and the evidence supporting each relationship. ThingsRecon combines external supplier discovery with Digital Proximity to show which dependencies sit closest to critical systems, helping teams answer “Are we affected?” and prioritise containment, communication and recovery. In practice, teams should record the supporting evidence, confirm ownership and business criticality, and connect the finding to an accountable workflow. This prevents a useful observation from becoming another isolated score or dashboard alert.

Why does supplier proximity matter?

Supplier proximity matters because the impact of a supplier incident depends on how the provider connects to the organisation, not only on the supplier’s general security posture. A provider executing code on a critical customer service creates a different exposure from one used for a low-impact administrative task. Digital Proximity measures the depth and importance of observable relationships, helping teams estimate potential blast radius and prioritise suppliers whose disruption or compromise would affect essential systems. It complements cyber hygiene and business intelligence rather than replacing them. In practice, teams should record the supporting evidence, confirm ownership and business criticality, and connect the finding to an accountable workflow. This prevents a useful observation from becoming another isolated score or dashboard alert.

What is relationship-specific risk?

Relationship-specific risk is the risk created by the way a particular organisation uses, connects to or depends on an external provider or asset. The same supplier can create very different exposure for two customers because its access, integration depth, data role and operational importance differ. Generic ratings describe the supplier as an entity; they cannot fully describe this customer-specific relationship. ThingsRecon uses external evidence and Digital Proximity to show how assets and suppliers connect to critical systems, helping teams prioritise according to probable business impact. In practice, teams should record the supporting evidence, confirm ownership and business criticality, and connect the finding to an accountable workflow. This prevents a useful observation from becoming another isolated score or dashboard alert. The strongest implementation combines external intelligence with internal knowledge, supplier engagement and documented risk decisions, creating a view that remains useful as the digital ecosystem changes.

Can a low-scoring supplier create limited business risk?

Yes. A supplier with weak cyber hygiene or a low external rating may still create limited business risk when its connection is peripheral, replaceable or isolated from critical systems. The supplier’s posture still deserves review, but remediation priority should reflect the organisation’s actual dependency and potential impact. Conversely, a well-rated supplier can create major concentration or operational risk when it is deeply embedded. ThingsRecon combines posture with Digital Proximity and business context so teams can avoid treating every supplier score as equally urgent. In practice, teams should record the supporting evidence, confirm ownership and business criticality, and connect the finding to an accountable workflow. This prevents a useful observation from becoming another isolated score or dashboard alert.

What is business-context risk prioritisation?

Business-context risk prioritisation ranks findings according to their likely effect on critical services, operations, data and organisational objectives, alongside technical severity. It considers factors such as asset importance, supplier dependency, internet exposure, relationship depth, concentration and resilience. This prevents teams from spending limited resources on severe but isolated issues while overlooking moderate weaknesses on systems that support essential activity. ThingsRecon combines external evidence with business intelligence and Digital Proximity to make those trade-offs more visible and defensible. In practice, teams should record the supporting evidence, confirm ownership and business criticality, and connect the finding to an accountable workflow. This prevents a useful observation from becoming another isolated score or dashboard alert. The strongest implementation combines external intelligence with internal knowledge, supplier engagement and documented risk decisions, creating a view that remains useful as the digital ecosystem changes.

What is proximity trending?

Proximity trending tracks how the closeness and importance of an asset or supplier relationship changes over time. A supplier may become more embedded as new integrations, scripts, domains or services appear, or less relevant after migration and offboarding. Tracking the trend can reveal growing dependency before it is reflected in procurement records. This concept should only be described as a ThingsRecon product capability when it is publicly available and validated; until then, it is best treated as a future analytical use of Digital Proximity data. In practice, teams should record the supporting evidence, confirm ownership and business criticality, and connect the finding to an accountable workflow. This prevents a useful observation from becoming another isolated score or dashboard alert.

What is fourth-party proximity?

Fourth-party proximity describes how closely an indirect supplier or shared provider connects to an organisation through one or more direct suppliers. It can help distinguish a distant dependency from a fourth party that underpins several critical services or suppliers. Measuring it requires reliable relationship mapping and evidence across multiple layers. This concept should only be presented as an available ThingsRecon feature after public product validation; until then, it is a useful framework for analysing indirect dependency and concentration risk. In practice, teams should record the supporting evidence, confirm ownership and business criticality, and connect the finding to an accountable workflow. This prevents a useful observation from becoming another isolated score or dashboard alert.

What is relationship-specific supplier risk?

Relationship-specific supplier risk is the risk created by the unique way a supplier supports or connects to one organisation. It considers integration depth, critical services, data flows, access, replaceability and digital dependencies. This explains why a supplier can be low priority for one customer and critical for another even when its general security rating is identical. ThingsRecon uses Digital Proximity and external evidence to make this customer-specific exposure visible and support more precise prioritisation. In practice, teams should record the supporting evidence, confirm ownership and business criticality, and connect the finding to an accountable workflow. This prevents a useful observation from becoming another isolated score or dashboard alert. The strongest implementation combines external intelligence with internal knowledge, supplier engagement and documented risk decisions, creating a view that remains useful as the digital ecosystem changes.

Share on Linkedin
Follow us on LinkedIn to get the latest insights.
ThingsRecon logo
get a personalized demo
What’s connected to you right now?
ThingsRecon logo
Thank you! You are now susbribed to The Recon Log
Oops! Something went wrong while submitting the form.
ALL THINGS
CYBER
A ThingsRecon podcast
from the edges of
the internet.
Share on LinkedinShare on XShare on Facebook