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SID-AUDIT-03 — WSCA-BE Tamper-Evident Audit Storage (FAU_STG_EXT)

PropertyValue
Ownerplatform
Categorytechnical
CSF Functiondetect
GroupAudit and Monitoring Controls

Description​

The WSCA-BE (go-r2ps-service) shall sign audit records using a dedicated HSM-resident audit signing key to provide tamper evidence.

Implementation requirements: (1) Dedicated ECDSA P-256 audit signing key generated in HSM during initial deployment (CKA_SENSITIVE=TRUE, CKA_EXTRACTABLE=FALSE). (2) Each audit record signed individually using ECDSA over the record's canonical JSON representation. (3) Append-only storage — signed records written to an immutable log store (append-only file, database with no UPDATE/DELETE, or dedicated audit service). (4) Fail-closed: if the audit subsystem is unavailable (HSM audit key inaccessible, storage full), the WSCA-BE SHALL deny all signing operations rather than operating without audit. (5) Audit records include: timestamp, user_id, event_type, operation_hash, success/failure, and a chained hash linking to the previous record for tamper detection.

Required for NOBCCS TR 4.3 FAU_STG_EXT (tamper-evident audit storage for CC evaluation of WSCA-BE).

Components​

  • R2PS Service
  • WSCA / HSM

Source References​