Payment Card DLP and Tokenization

Overview#

Payment card numbers appear in police reports, call recordings, screenshots, receipts, scanned statements, chat logs, and body-worn camera transcripts more often than teams expect. A single primary account number in an evidence export or case summary can create PCI exposure even when the investigation itself has nothing to do with payments.

The Payment Card DLP and Tokenization module detects card-PAN material across uploads, OCR text, media-derived transcripts, and analyst notes, then applies deterministic tokenization, policy-based redaction, or controlled reveal according to the organisation's security posture. The result is a review workflow where analysts can work with evidence context while raw card data remains protected by tenant-specific key policy and audited access gates.

Key Features#

Context-Aware Card Detection: Luhn validation, issuer pattern checks, surrounding keyword context, separator handling, and evidence-source signals reduce false positives while catching realistic PAN formats.
Upload-Time Enforcement: Scans run against the final bytes that enter evidence storage, preventing pre-scan changes or client-side transformations from bypassing DLP controls.
OCR and Transcript Protection: Raw OCR text, handwriting recognition output, and media transcripts are inspected before broader search or analytics workflows can expose sensitive card values.
Deterministic Tokenization: Repeated appearances of the same card value can resolve to the same protected token for investigation correlation without revealing the underlying PAN.
Tenant BYOK Vault Control: Organisations can manage tenant-specific key material and rotation policy so token protection follows the tenant's own cryptographic boundary.
Fail-Closed Key Enforcement: If key access is unavailable or policy cannot be confirmed, reveal and tokenization paths fail closed instead of falling back to weaker handling.
RBAC-Gated Reveal: Raw values are available only through explicit, time-bound, role-controlled reveal actions that are logged independently from ordinary evidence viewing.
Redaction Integration: Payment-card findings can feed evidence redaction and export workflows so disclosure bundles do not leak hidden card values in text layers or derived media.

Use Cases#

PCI exposure reduction for evidence rooms that ingest screenshots, receipts, statements, payment pages, and financial communications.
OCR-safe disclosure preparation where card values in scanned documents are tokenized before they become searchable.
Financial crime investigation support where repeated card references need correlation but raw values should not be broadly visible.
Secure analyst reveal where a small number of authorised users can access a protected value for a documented investigative purpose.
Tenant-controlled cryptography for government and enterprise deployments that require bring-your-own-key separation across organisations.
Durable audit parity where DLP detections, tokenization decisions, reveal grants, and reveal denials remain available for compliance review.

Integration#

The module sits in the ingestion, OCR, redaction, search, and export paths. It can protect text before indexing, feed redaction candidates to reviewers, and write durable audit records whenever a protected value is detected, transformed, revealed, or denied. Policy configuration is managed by tenant administrators with role checks that prevent local changes from weakening platform-level controls.

Open Standards#

PCI DSS v4.0: Cardholder data handling aligns with requirements for storage minimisation, access control, masking, logging, and cryptographic protection.
ISO/IEC 7812: Issuer identification and primary account number structure follow the international numbering model used for payment cards.
Luhn Algorithm (ISO/IEC 7812 practice): Check-digit validation helps distinguish likely card values from unrelated numeric identifiers.
AES-GCM (NIST SP 800-38D): Authenticated encryption protects raw sensitive values when reversible token recovery is permitted by policy.
NIST SP 800-57: Key lifecycle management, rotation, and tenant-specific key separation follow recognised cryptographic key management guidance.
SHA-256 (FIPS 180-4): Deterministic lookup material and audit fingerprints use a standard cryptographic hash function without exposing raw card values.
ISO 8601: Detection, tokenization, reveal, denial, and key-rotation events use a consistent timestamp representation for audit and reporting.
GDPR (EU Regulation 2016/679): Data minimisation, purpose limitation, access restriction, and erasure handling are applied to personal financial identifiers.

Security and Compliance#

Raw PAN access is exceptional, role-gated, and auditable. Tokenization and reveal paths are tenant-isolated, key-dependent, and fail closed. Detection decisions are recorded separately from ordinary evidence viewing so compliance teams can prove that protected values were handled intentionally rather than accidentally exposed.

Last Reviewed: 2026-06-25 Last Updated: 2026-06-25