Does IE10 Enforce Credential Expiration for Zone-Based Integrated Authentication?

Direct Answer

No. IE10 does not enforce credential expiration at the browser or zone level. Credential lifetime is managed entirely by the Windows security subsystem (LSASS, Kerberos, NTLM), not by IE zone settings. Zone configuration only controls whether automatic logon is attempted — it does not limit caching scope or impose expiration.

What Happens When Cached Credentials Expire

Behavior depends on the authentication protocol in use:

• Kerberos (default for domain-joined Local Intranet): Tickets expire per domain policy (default 10-hour TGT, 10-hour service tickets). On expiry, IE10 transparently renews the ticket on the next request — the user is not re-prompted unless the TGT itself is expired or the user has no valid ticket.
• NTLM (fallback or non-domain environments): Credentials are cached in memory by LSASS until logoff, explicit credential purge (rundll32.exe keymgr.dll,KRShowKeyMgr), or net session /delete. No automatic expiration occurs.

When expired or invalid credentials are presented to a Local Intranet site, IE10 either silently retries with a renewed Kerberos ticket or falls back to NTLM/anonymous access based on the zone's "User Authentication" setting. It does not fail silently, and it does not prompt the user unless the zone is explicitly set to "Prompt for user name and password."

Zone Settings and Their Actual Effect

The "User Authentication" setting for each zone (found in Internet Options → Security → Custom Level) offers three options:

• Automatic logon with current user name and password — sends credentials silently (default for Local Intranet).
• Prompt for user name and password — forces a credential dialog on each new session (not per request).
• Anonymous logon — sends no credentials.

None of these options limit how long credentials are cached or enforce expiration. They only gate the initial decision to send credentials.

Least-Privilege Authentication: Zone Config Is Insufficient

Least-privilege authentication cannot be achieved through IE zone configuration alone. Effective controls require external mechanisms:

• Kerberos policy: Maximum lifetime for service ticket and Maximum lifetime for user ticket via Group Policy.
• Credential Manager policies: disable credential persistence via Network access: Do not allow storage of passwords and credentials for network authentication.
• Application-level token expiration (e.g., short-lived session cookies, OAuth tokens).
• Explicit credential purge scripts at session boundaries.

Verification Steps (If You Need to Confirm on Original Hardware)

1. On a clean Windows 8.1 VM joined to a test domain, configure a Local Intranet site with "Automatic logon with current user name and password."
2. Access the site, then reduce the Kerberos max ticket age via GPO (Maximum lifetime for user ticket = 10 minutes) or wait for natural expiry.
3. Refresh the page and capture a network trace (Wireshark/Kerberos logs) — observe transparent TGT renewal without user prompt.
4. Run klist before and after expiry to confirm ticket renewal.
5. Test NTLM fallback by disabling Kerberos encryption types via GPO and repeat — credentials persist until logoff.
6. Change the zone to "Prompt for user name and password" and verify a re-prompt occurs on each new browser session.

One diagnostic detail that would change the recommendation: Are you observing this behavior on original Windows 8/8.1 hardware/VMs, or on a later OS using IE10 compatibility mode? Compatibility modes alter the auth stack and do not replicate original LSASS/credential manager behavior.