ia-5-2-public-key-based-authentication

name	IA-5(2)_public-key-based-authentication
description	For public key-based authentication: Enforce authorized access to the corresponding private key; and Map the authenticated identity to the account of
category	authentication
version	5.2.0
author	cyberstrike-official
tags	["nist","sp800-53","rev5","ia-5-2","ia","enhancement"]
tech_stack	["aws","azure","active-directory","linux","windows"]
cwe_ids	["CWE-287"]
chains_with	["IA-3","SC-17"]
prerequisites	["IA-5"]
severity_boost	{"IA-3":"Chain with IA-3 for comprehensive security coverage","SC-17":"Chain with SC-17 for comprehensive security coverage"}

IA-5(2) Public Key-based Authentication

Enhancement of: IA-5

High-Level Description

Family: Identification and Authentication (IA) Framework: NIST SP 800-53 Rev 5

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.

What to Check

• Verify IA-5(2) Public Key-based Authentication is documented in SSP
• Validate all 4 control requirements are implemented
• Confirm control is operating effectively
• Review evidence of continuous monitoring for IA-5(2)
• Verify enhancement builds upon base control IA-5

How to Test

Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for IA-5(2) implementation details. Verify the organization has documented how this control is satisfied.

Step 2: Validate Implementation

# For cloud environments, use cloud-audit-mcp tools
# For on-premises, review system configurations directly

# Example: Check if account management policies exist
grep -r "account.management\|access.control" /etc/security/ 2>/dev/null

Step 3: Test Operating Effectiveness

Verify the control is actively functioning, not just documented. Check logs, configurations, and operational evidence.

Tools

Tool	Purpose	Usage
cloud-audit-mcp	Check authentication settings	cloud_audit_iam_policies
hackbrowser-mcp	Test authentication mechanisms	browser_auth_test

Remediation Guide