PKCS#8 Private Key Header

Detects PKCS#8 private key PEM headers in source code, configuration files, and documents. Private keys should never appear in plaintext.

Type

regex

Engine

universal

Confidence

high

Confidence justification

High confidence: structurally constrained pattern with corroborative keyword support reduces false positive rates significantly. Added context gating and exclusion rules improve precision and reduce incidental matches.

Detection quality

Verified

Jurisdictions

global

Regulations

Criminal Code Act 1995 (Cth)

Frameworks

CIS Controls, ISO 27001, NIST CSF, PCI-DSS, SOC 2

Data categories

credentials, security

Scope

specific

Platform compatibility

Purview: Compatible, GCP DLP: Compatible, Macie: Compatible, Zscaler: Compatible, Palo Alto: Compatible, Netskope: Compatible

Pattern

-----BEGIN PRIVATE KEY-----

Corroborative evidence keywords

private key, secret key, key file, PEM, certificate, RSA, cryptographic, api key, api_key, apikey, access key, access token, auth token, authorization, bearer, conn str, connection string, connectionstring, cookie, credential (+42 more)

Proximity: 300 characters

Should match

• -----BEGIN PRIVATE KEY----- — PKCS#8 private key PEM header
• -----BEGIN PRIVATE KEY----- MIIE... — PKCS#8 key with data following header
• -----BEGIN PRIVATE KEY----- Proc-Type: — Encrypted PKCS#8 private key header

Should not match

• -----BEGIN PUBLIC KEY----- — Public key, not private
• -----BEGIN CERTIFICATE----- — Certificate, not private key
• template example placeholder record identifier — Template/sample context should be excluded even when anchor words are present

Known false positives

• PEM-encoded certificates or public keys that use similar header formats Mitigation: The pattern specifically matches the private key header text, but verify the full PEM block contains actual key material.

Collections

• Cloud Credentials & API Keys