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IA-5(2) IA · Identification and Authentication

Public Key-based Authentication

LOW ✓ MODERATE ✓ HIGH
1 Overlay 2 Related Controls
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Requirements NIST SOURCE

    1. (1)Enforce authorized access to the corresponding private key; and
    2. (2)Map the authenticated identity to the account of the individual or group; and
    1. (1)Validate certificates by constructing and verifying a certification path to an accepted trust anchor, including checking certificate status information; and
    2. (2)Implement a local cache of revocation data to support path discovery and validation.
Discussion (NIST Supplemental Guidance)

Public key cryptography is a valid authentication mechanism for individuals, machines, and devices. For PKI solutions, status information for certification paths includes certificate revocation lists or certificate status protocol responses. For PIV cards, certificate validation involves the construction and verification of a certification path to the Common Policy Root trust anchor, which includes certificate policy processing. Implementing a local cache of revocation data to support path discovery and validation also supports system availability in situations where organizations are unable to access revocation information via the network.

Implementation Guidance

Engineering Interpretation

Original engineering commentary written for this explorer — not NIST source text and not authoritative guidance.

No engineering interpretation has been authored for IA-5(2) yet. This section is architected to receive it — see the Requirements and Assessment sections above for the authoritative NIST source content in the meantime.

Assessment

NIST SP 800-53A REV 5.2.0

Assessment Objectives

  1. authorized access to the corresponding private key is enforced for public key-based authentication;
  2. the authenticated identity is mapped to the account of the individual or group for public key-based authentication;
  3. when public key infrastructure (PKI) is used, certificates are validated by constructing and verifying a certification path to an accepted trust anchor, including checking certificate status information;
  4. when public key infrastructure (PKI) is used, a local cache of revocation data is implemented to support path discovery and validation.

Examine

[SELECT FROM: Identification and authentication policy; procedures addressing authenticator management; system security plan; system design documentation; system configuration settings and associated documentation; PKI certification validation records; PKI certification revocation lists; other relevant documents or records].

Interview

[SELECT FROM: Organizational personnel with PKI-based, authenticator management responsibilities; organizational personnel with information security responsibilities; system/network administrators; system developers].

Test

[SELECT FROM: Mechanisms supporting and/or implementing PKI-based, authenticator management capability].

Overlays

Showing the OT/ICS overlay for the parent control IA-5 — see the IA-5(2) entries within each baseline below.

OT/ICS Overlay SP 800-82r3

NIST SP 800-82r3 Appendix F, Table 22. Blank baseline means the control/control enhancement is not selected in that initial OT baseline.

LOW

  • Base control: Included (matches standard baseline)
  • Included: (1)

MODERATE

  • Base control: Included (matches standard baseline)
  • Included: (1) (2) (6)

HIGH

  • Base control: Included (matches standard baseline)
  • Included: (1) (2) (6)

STIGs & CCIs

No STIG checks or CCI mappings are currently loaded for IA-5(2). This section is architected to display, per product: STIG ID, Finding ID, Severity, Title, Description, Check, Fix, CCI, and NIST control mapping — but nothing is populated here until a real DISA STIG/CCI dataset is ingested.

Learn more about STIG/CCI integration →

Evidence

Potential Evidence — Derived

Categorized from the SP 800-53A "Examine"/"Test" artifact list above by keyword — not an authoritative NIST evidence list.

Policy

  • Identification and authentication policy
  • system security plan

Configuration

  • system design documentation
  • system configuration settings and associated documentation

Testing

  • Mechanisms supporting and/or implementing PKI-based, authenticator management capability

Other Records

  • procedures addressing authenticator management
  • PKI certification validation records
  • PKI certification revocation lists
  • other relevant documents or records