Agencies should treat flexibility as an access option, not a relaxation of control. In practice, that means preserving strong authentication, device trust, and authorization checks while allowing multiple approved credentials such as mobile-derived credentials or FIDO2. The goal is to improve user convenience and deployment options while still enforcing who can enter, what they can reach, and under what conditions.
Why flexibility should change the credential options, not the rule set
Agencies can add flexibility by broadening how a user proves access, but the authorization decision itself should stay strict and explicit. That means the control objective remains the same: verify the person or device, evaluate trust, and then decide whether entry is allowed under the current policy. Flexibility is about supported methods, not about softening approval.
In practice, the best design is to separate authentication from authorization. A mobile-derived credential or FIDO2 token can improve usability, but it should still feed the same access policy, not bypass it. That distinction matters when agencies want multiple approved pathways while preserving consistent enforcement for doors, zones, schedules, and escalation conditions.
That approach also aligns with modern access models that distinguish who is presenting a credential from what that credential is allowed to do. Authorisation Models Guide is useful here because the agency question is ultimately about preserving policy decisions while widening the set of acceptable inputs.
How to support multiple approved credentials without weakening control
A flexible physical access programme should define approved credential types, assurance levels, and fallback rules before rollout. If the new method is meant to replace a badge, then the replacement must meet the same or stronger trust bar, including strong authentication, device trust, revocation handling, and clear recovery procedures when a phone is lost or a token is unavailable.
The practical design point is that convenience should be introduced at the edge of the control, not at the point of authorization. Agencies can allow different user experiences, but the backend decision should still answer the same questions: is the credential valid, is the device trusted, is the user entitled to this area, and does the current context permit entry?
For agencies managing both human and machine access patterns, foundational IAM thinking helps keep that separation clear. IAM and IGA Basics supports the wider discipline of keeping identity proofing, entitlement decisions, and lifecycle control distinct even when the front-end access experience becomes more flexible.
Where flexibility includes mobile credentials, agencies should also plan for device compromise, remote wipe, reassignment, and rapid deprovisioning. Those are not edge cases in practice, they are part of making the control durable at scale.
What strong physical access authorization looks like in practice
Good physical access control is policy driven, not credential driven. The organization should be able to accept more than one credential format while still enforcing role, location, time, and exception rules consistently. That usually means central policy, a reliable identity source, and logging that makes each access event attributable enough to investigate later.
When agencies want multiple approved credentials, the important test is whether the access decision remains explainable after the fact. If a user entered because “the app worked,” the program is too loose. If they entered because a valid credential met a defined policy for a specific zone at a specific time, the flexibility has been implemented correctly.
That is also why access review and lifecycle discipline matter even for physical systems. NHI Lifecycle Management Guide is relevant as a lifecycle reference because the same operational problem appears whenever credentials must be issued, rotated, revoked, and monitored without losing control of access.
Risk and Threat Considerations
Flexibility becomes a security problem when it is implemented as a parallel trust path instead of a controlled alternative. The main risk is policy drift: one credential type gets stronger checks, another quietly becomes easier to misuse, revoke more slowly, or share more easily across users and devices.
Failure mechanism: Weak onboarding, poor revocation, or inconsistent device trust can let an approved credential outlive the person or device it was issued to, turning convenience into unauthorized entry risk.
Impact: That can produce access bypass, orphaned access, delayed detection of misuse, and broader physical exposure if a compromised credential works in high-value zones or after the original user should no longer be able to enter.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
NIST SP 800-53 Rev 5, CIS Controls v8 and OWASP ASVS set the technical controls, while ISO/IEC 27001:2022 defines the regulatory obligations.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST SP 800-53 Rev 5 | IA-2 — Identification and Authentication (Organizational Users) | Physical access still depends on proving the user or device before entry. |
| AC-6 — Least Privilege | Flexible access must not broaden who can enter which areas or under what conditions. | |
| IA-5 — Authenticator Management | Multiple approved credentials need issuance, rotation, and revocation discipline. | |
| Recommendation — Require strong authentication before any physical access decision is made. Limit each credential to the minimum zones and actions needed. Manage credential lifecycle so approved methods stay current and revocable. | ||
| ISO/IEC 27001:2022 | A.5.15 — Access control | The question is about preserving authorization requirements while broadening access methods. |
| A.5.16 — Identity management | Flexible physical access still requires reliable identity binding behind each credential. | |
| Recommendation — Define access rules that stay consistent across all approved credential types. Bind each credential option to a verified identity and ownership process. | ||
| CIS Controls v8 | CIS-6 — Access Control Management | Agencies need a prescriptive access-control baseline for multiple credential types. |
| Recommendation — Standardise access approval, enforcement, and revocation across credential options. | ||
| OWASP ASVS | V6 — Authentication | Approved credentials must still provide strong authentication before access is granted. |
| V8 — Authorization | The core problem is preserving authorization while adding flexibility. | |
| V13 — Configuration | Credential choice must be backed by correct policy and deployment configuration. | |
| Recommendation — Enforce strong authentication requirements for every accepted credential method. Keep authorization checks unchanged when introducing new access methods. Configure each access method so policy enforcement remains consistent. | ||
Practitioner Guidance
What to verify: Confirm that every credential type, including mobile and FIDO2 options, is bound to the same policy engine, the same revocation process, and the same audit trail. If one path cannot be disabled or reviewed as quickly as the others, it is not an equivalent control.
Decision rule: If the new credential method improves convenience but weakens identity assurance, device binding, or exception handling, treat it as a pilot only. If it preserves those controls and simply changes the user experience, it can be adopted as an approved option.
Common mistake: Agencies often validate the new credential method but forget to test the operational failure cases, such as lost phones, stale enrolments, shared devices, and emergency access. Those cases are where flexible access usually fails first.
Practitioner takeaway: The right design adds choice at the credential layer while keeping authorization decisions centralized, explicit, and revocable, so flexibility expands usability without expanding privilege.
Related resources from NHI Mgmt Group
- How should security teams reduce authorization latency without weakening access control?
- How should organisations use AI in access request approval without weakening control?
- How should organisations automate user access reviews without weakening control quality?
- How should security teams reduce MFA fatigue risk without weakening access control?
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on September 28, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
