Identity & Access Management:
Secure the New Perimeter
Identity is the new perimeter. Castle-and-moat security is dead. This guide covers authentication architecture, Zero Trust, FIDO2/Passkeys, Privileged Access Management, Non-Human Identities, and compliance -- sourced from NIST, OWASP, Verizon DBIR, and industry research.
What Is Identity & Access Management?
Identity and Access Management (IAM) is the discipline of policies, technologies, and processes used to manage and control user identities and their access to organizational resources. IAM determines who can access what, when, how, and under what conditions.
Identity is the new perimeter. The traditional castle-and-moat model -- where a hardened network boundary protected internal resources -- is dead. Cloud adoption, remote workforces, and API-driven architectures have dissolved the network edge. Every access request, whether from a human or a machine, must be verified independently. IAM is the cornerstone of Zero Trust architecture.
Who Needs This
68% of breaches involve a human element and 31% involve stolen credentials (Verizon DBIR 2024). The FBI received 193,407 phishing complaints in 2024. 14% of incidents involve MFA fatigue attacks. Non-human identities outnumber humans 46:1 -- and in some environments, up to 82:1. 50% of organizations have experienced a breach tied to non-human identities.
Key Concepts
IAM spans authentication (verifying who you are), authorization (enforcing what you can access), identity governance (ensuring compliance and audit readiness), privileged access management (controlling elevated permissions), and identity lifecycle management (provisioning and deprovisioning from hire to departure). This page covers each domain with practitioner-level depth.
The IAM Threat Landscape
The Five Pillars of IAM
Key IAM Security Terms
Authentication Methods Compared
Zero Trust Architecture: NIST 800-207
The Policy Engine ingests telemetry from multiple sources and produces a real-time trust score for every access request. It evaluates identity claims, device health, network context, and historical behavior to determine whether access should be granted, denied, or stepped up.
The PA acts as the command and control layer. It translates policy decisions into actionable configurations -- creating time-bound tokens, establishing encrypted tunnels, and revoking access when trust scores drop below threshold.
PEPs sit at every resource boundary -- application, database, API, file share. They intercept every request and query the PA for authorization. If the PA denies the request, the PEP blocks it. There is no implicit access path that bypasses enforcement.
Authentication at login is not enough. Continuous verification monitors session behavior, device posture changes, and network anomalies throughout the entire session. If a device becomes non-compliant or behavior deviates from baseline, access is revoked or stepped up immediately.
Micro-segmentation divides the network into isolated zones, each with its own access controls. Even if an attacker compromises one identity, they cannot move laterally to other zones without separate, verified authorization. This limits blast radius and contains breaches.
Least privilege ensures identities receive only the minimum access required for their current task. JIT access takes this further by granting elevated permissions on demand with automatic expiration. No identity retains standing privileged access -- reducing the window of opportunity for attackers.
Identity Lifecycle: Joiner-Mover-Leaver
Non-Human Identities (NHI): The 46:1 Problem
Non-human identities include service accounts, API keys, CI/CD tokens, AI agents, and machine identities. They often have broader access than human users, longer credential lifespans, and weaker governance. The OWASP NHI Top 10 now classifies the most critical risks.
Key risks: Improper offboarding of service accounts, overprivileged machine identities, insecure cloud configuration, hardcoded secrets in code repositories, and AI agents with autonomous access to production systems.
NHI Security Maturity Model
Service Accounts: Persistent machine identities accessing databases, APIs, and infrastructure. API Keys: Static tokens for service-to-service authentication. CI/CD Tokens: Pipeline credentials with broad deployment access. AI Agents: Autonomous identities making decisions and accessing production systems without human approval loops.
Notable IAM Breaches
IAM Compliance Requirements
- Unique user identification for all ePHI access
- Identity proofing before credential issuance
- Role-based access controls with minimum necessary
- Tamper-proof audit logs for all identity events
- Phishing-resistant MFA for CDE access
- Unique IDs for all users with system access
- Strict access controls and least privilege
- Regular access reviews and prompt deprovisioning
- Data consent and minimization controls
- Support for data subject access requests
- Privacy-preserving identity verification
- Right to erasure and data portability
IAM & Compliance Controls
Requirement 8: Identify users and authenticate access — MFA required for all access to cardholder data, 12-character minimum passwords, idle timeout.
Requirement 8.3.6: MFA for all non-console administrative access.
Requirement 8.6: System and service account management — applies to NHI controls.
CC6.2: User registration and authorization — identity lifecycle (joiner-mover-leaver).
CC6.3: Role-based access and least privilege — authorization model enforcement.
CC6.8: Restricting access to system components — PAM controls for privileged accounts.
A.5.16: Identity management — identity lifecycle, unique IDs, shared account prohibition.
A.5.17: Authentication information — password policy, MFA, credential management.
A.5.18: Access rights — provisioning, review, revocation. Joiner-mover-leaver process.
AAL2: Two-factor authentication — password + OTP or push notification.
AAL3: Hardware-based authentication — FIDO2/passkeys, phishing-resistant MFA. Required for high-assurance applications.
IAL1-3: Identity proofing levels from self-asserted to in-person verification.
IAM Certifications
IAM Security Articles
Start Securing Your Identity Perimeter
Explore the full IAM ecosystem -- Zero Trust architecture, phishing-resistant authentication, privileged access controls, and non-human identity governance. Practitioner resources, no sales pitch.