Standard

PCI DSS: scope discipline before anything else

Every PCI DSS conversation about AI should start with scope, not features. If cardholder data never enters the AI path, most of this is a short conversation. If it can enter, the gateway is a component in scope and every control below applies.

The instrument
PCI DSS v4.0.1, with the future-dated requirements mandatory since 31 March 2025
Status
In force
Who it applies to
Merchants and service providers whose AI use cases can reach cardholder data.

Where AI-FW fits

PCI DSS is assessed against the cardholder data environment. An AI gateway is in scope the moment cardholder data can reach it, through a prompt, an uploaded file, an agent payload or a model response. AI-FW's most valuable contribution is provable exclusion: a blocking rule and a data-flow statement that keep the AI path out of the environment altogether.

What stays with you

Read this list first. It is the boundary of what a product can do for you, and it is where the remaining work sits.

  • Network segmentation, firewalling and wireless controls
  • Physical security, and the annual penetration test
  • Approved scanning vendor scans
  • Key custodian procedures for the keys you supply
  • Personnel screening and security awareness training

What the framework asks, and what the product does

The obligations that touch the AI path, paired with the capability that answers each one. Everything else in this framework is organisational work, listed above.

Scope reduction
What it asks

Reduce where cardholder data lives and flows

What AI-FW does

A blocking rule for card number patterns, so the AI path can be documented as out of scope rather than argued about

Stored account data
What it asks

Protect stored cardholder data, and mask the number on display

What AI-FW does

Metadata-first capture, masking rules for card data, and no raw prompt or response storage unless your policy turns it on

Key management
What it asks

Protect keys and never expose them

What AI-FW does

Provider credentials held server-side, secrets masked in configuration, and no key material inside evidence packs or logs

Encryption in transit
What it asks

Encrypt cardholder data across open networks

What AI-FW does

TLS on every listener endpoint and on upstream model calls

Secure development
What it asks

Build and maintain secure systems, and manage vulnerabilities

What AI-FW does

Images pinned by tag and digest, with dependency vulnerability review as part of release checks

Public-facing protection
What it asks

Protect public-facing applications from attack

What AI-FW does

Prompt and response inspection for injection and abuse patterns, with rate and quota enforcement to bound how hard a caller can try

Least privilege
What it asks

Limit access by business need to know

What AI-FW does

Role policies, per-agent identity, owner-scoped views, and an audit trail of every access change

Authentication
What it asks

Identify users, and use strong authentication

What AI-FW does

Hashed and revocable keys, client certificates validated against your trust anchors, and Kerberos with allowlists

Audit logging
What it asks

Record who did what, when, from where, and whether it succeeded

What AI-FW does

Transaction and access records with identity, model, outcome, source and timestamp, plus a separate record of administrative change

Log review
What it asks

Review records, and detect failures

What AI-FW does

Activity, error and access views for routine review, and drift findings raised when a required rule is switched off

Retention
What it asks

Keep twelve months, with three months readily available

What AI-FW does

Retention is a setting, so the twelve-month requirement is a value rather than a limitation

Third-party management
What it asks

Know and manage your service providers

What AI-FW does

A model inventory that enumerates every provider and endpoint in the AI path, ready for the responsibility matrix

A rule pack to start from

The enforcement that makes the controls real. Severity runs 1 to 5, and a rule that is switched off reports as a gap, so these are meant to be live from day one.

Card number patterns, track data, verification codes, magnetic stripe dataInboundBlockSeverity 5

Keeping card data out of the AI path is the scope decision that matters most

Card data echoed in a model responseOutboundBlockSeverity 5

A model can repeat what it was given, including across a conversation boundary

Card-like data in uploads or captured logsInboundBlockSeverity 5

Files and logs are the routes people forget

Prompt injection and exfiltration attemptsInboundBlockSeverity 4

Public-facing application protection

Provider not on the responsibility matrixInboundBlockSeverity 4

Keeps the third-party register true by construction

What the evidence pack contains

Per period, and without prompt or response content, which is what makes it safe to hand over.

  • Card-data block rule stateEnabled: a disabled scope rule is a scope-changing event
  • Masking rule stateWhere content capture is on, masking is applied
  • Retention valuesAt least twelve months, with evidence retention aligned
  • Authentication configurationOnly the methods in use, with no shared credentials
  • Third-party inventoryEvery provider and endpoint in the AI path

Customer responsibilities and sources

Yours to run
  • Determine and document whether cardholder data can enter the AI path, and include the gateway in scope if it can.
  • Segment the network, control wireless access and secure physical locations.
  • Run vulnerability scanning and the annual penetration test.
  • Operate key management procedures and custodian duties for any key you supply.
  • Screen personnel and run security awareness training, and maintain the responsibility matrix for third parties.

Common questions

No, and that distinction is worth money. It is in scope if cardholder data can reach it. If you can show a blocking rule that refuses card number patterns, plus a data-flow statement that documents the boundary, the strongest position is that the AI path stays out of the cardholder data environment. If card data can enter, everything above applies.

Masking protects the value while it is stored or displayed. Blocking prevents the value from entering the path at all, which is what keeps the system out of scope. Masking still matters where content capture is enabled, but it is the second line, not the first.

No. Records carry identity, model, decision, rule, outcome and timing. Evidence packs exclude payloads, so there is no card data and no secret material in the artefacts you hand to an assessor.

Validate it yourself with our Technical Plan

Ask us to run this framework against your own environment: the rules that would be created, what the assessment reports, and what the evidence pack contains for a real period.

This page maps product capabilities to published expectations. It is not legal, audit or certification advice, and it creates no compliance representation. Applicability and sufficiency are judgements for your counsel and, where relevant, your auditor, assessor or certification body. Framework details are current as reviewed; check the primary sources above, and the page itself, before relying on a date or a threshold.