Device Lock is the requirement behind the screen that locks itself and hides what was on it. It prevents access to a system when a user steps away without logging out, holds that lock until the user re-authenticates, and hides whatever was on the display behind a publicly viewable image. In R2 this was called "session lock." R3 renamed it to Device Lock and, importantly, added a new obligation: the lock has to be retained until the user reestablishes access using identification and authentication procedures. It sits alongside Session Termination (03.01.11), but the two are different. A device lock is a temporary hold for a user who intends to return, while session termination ends the session entirely.
A common difficulty with this requirement is treating it as a single screen-saver setting. It is three separate obligations: the trigger that engages the lock, the requirement that the lock stays until re-authentication, and the concealment of on-screen information. A screen saver that dims the display but does not require re-authentication, or that does not hide the previous content, fails part of the requirement even though something is happening after inactivity.
Where things stand for companies facing the transition from NIST 800-171 R2 to R3:
The following is reproduced verbatim from NIST 800-171 R3, requirement 03.01.10 Device Lock. Only the formatting has been adjusted for readability. This requirement has three (3) lettered parts:
The source controls are AC-11 and AC-11(01) from NIST 800-53. Part a is a Selection, so you choose automatic inactivity locking, user-initiated locking, or both. Per the NIST discussion, device locks are temporary actions taken when a user departs the immediate vicinity but does not want to log out, and they are not an acceptable substitute for logging out when policy requires it. Publicly viewable images can include a screen saver pattern, a solid color, a photo, a clock, a battery indicator, or a blank screen, as long as Controlled Unclassified Information (CUI) is not displayed. You can read the requirement directly at NIST 800-171 R3, 03.01.10 (p. 13).
One (1) value sits inside this requirement. Depending on your contract, your organization may be permitted to define it. Organizations in the DIB subject to CMMC are not, because the DoD has defined it as policy.
The value below comes from Attachment A of the DoD Chief Information Officer (CIO) memorandum dated 10 April 2025 (signed David W. McKeown). The memo identifies each parameter by requirement sub-part, while NIST 800-171A R3 identifies the same parameter by ODP number. Both identifiers appear below so you can match your System Security Plan (SSP) language to either document.
Note the asymmetry: NIST 800-171A R3 decomposes this requirement into two (2) Organization-Defined Parameters, while the DoD memorandum addresses them with one (1) entry, because a single bracketed assignment in the requirement text covers more than one parameter under assessment. Each ODP still needs its own answer in the System Security Plan (SSP).
The memo states that its values "will be updated as necessary," so confirm against the current version before writing them into policy.
NIST 800-171A R3 breaks 03.01.10 into five (5) assessment objectives: two (2) Organization-Defined Parameters (ODPs) and three (3) determination statements. These AOs are:
The two (2) ODPs cover the selection of the locking method and the inactivity timeout. If you are a DoD contractor, they are not open questions. Per the DoD-specified ODP value in ComplianceForge's NIST 800-171 R3 Transition Guide, the timeout is set to initiating a device lock after at most fifteen (15) minutes of inactivity and requiring the user to initiate a device lock before leaving the system unattended, which selects both parameter values. The full guidance on assessment methods and objects, is in NIST 800-171A R3, 03.01.10 (p. 15).
Examine: access control policy and procedures; procedures for session lock and identification and authentication; system design documentation; system configuration settings; display screen with session lock activated; system security plan.
Interview: personnel with information security responsibilities; system developers; system administrators.
Test: mechanisms for implementing the access control policy for session lock; session lock mechanisms.
03.01.10 maps from NIST 800-171 R2 requirement 3.1.10 (use session lock with pattern-hiding displays to prevent access and viewing of data after a period of inactivity):
Mapped against the five (5) AOs, four (4) are direct (minimal effort) and one (1) is net new (significant effort), with none indirect and none with no mapping. The renamed control carries forward cleanly except for the new re-authentication objective. R2 required the lock and the pattern-hiding display but did not separately assess that the lock is retained until the user reestablishes access. A.03.01.10.b makes that explicit, so a lock that clears on any keypress rather than requiring re-authentication is now a gap.
Source Controls in NIST 800-53 R5:
Secure Controls Framework (SCF) Crosswalk
Organizations running a single control set across multiple frameworks can satisfy 03.01.10 through the following SCF controls:
The crosswalks from NIST 800-171 R3 and NIST 800-171A R3 to the SCF are available at no cost through the SCF Set Theory Relationship Mapping (STRM): https://securecontrolsframework.com/start-here/set-theory-relationship-mapping-strm. The STRM also carries the relationship type for each mapping (Equal, Subset Of, Intersects With), which tells you whether an SCF control fully satisfies the requirement or only part of it. Mapping above taken from SCF 2026.3.
The following are issues teams may encounter rather than certainties. They are about the new objective and the three-part structure, each of which needs documented evidence of due diligence and due care such as policies, standards, procedures, and configuration screenshots:
Reasonable objective evidence for an assessment is often subjective. The following examples of evidence to address NIST 800-171 R3 03.01.10 are sourced from the SCF Evidence Request List (ERL), available at https://securecontrolsframework.com/free-content/scf-download. These ERL artifacts are mapped to NIST 800-171 R3 03.01.10 through SCF controls. They establish a starting point for discussions on what an organization needs to have for evidence of due diligence and due care to withstand external scrutiny by an assessor or regulator.
Alongside these, keep the System Security Plan (SSP) narrative for 03.01.10 recording the ODP values you adopted.
With four (4) AOs mapping directly and one net new, 03.01.10 is a light lift with a single new obligation to close. A realistic sequence:
What value does the DoD require for the organization-defined parameter in NIST 800-171 R3 03.01.10? R3 leaves the value to the organization. For the DIB, the DoD set it in the 10 April 2025 memorandum under ODP identifier 03.01.10.a: initiating a device lock after “at most 15 minutes” of inactivity and requiring the user to initiate a device lock before leaving the system unattended.
How many assessment objectives does NIST 800-171 R3 03.01.10 have? NIST 800-171A R3 breaks 03.01.10 into five (5) assessment objectives: two (2) Organization-Defined Parameters (ODPs) and three (3) determination statements. An assessor works through each one separately, so each needs its own evidence.
Which NIST 800-53 R5 controls does NIST 800-171 R3 03.01.10 come from? AC-11, AC-11(01).
Where does NIST 800-171 R3 03.01.10 sit in the NIST 800-171 R3 Kill Chain? Phase 12, Secure Baseline Configurations (SBC). The Kill Chain is a phased model for sequencing R3 implementation, and it assigns this requirement to that phase.
03.01.10 Device Lock prevents access after inactivity or on demand, holds the lock until the user re-authenticates, and hides what was on the screen. It maps from R2 3.1.10 (session lock) with four (4) assessment objectives transitioning directly and one net new, the requirement that the lock be retained until re-authentication. The recurring problem is treating it as a single screen-saver setting. Set the timeout and method, require re-authentication to clear the lock, conceal the display, and keep screen shots as evidence.
Authoritative sources:
Authoritative sources:
This guide reproduces U.S. Government text from NIST 800-171 R3 and NIST 800-171A R3 and references the DoD ODP memorandum of 10 April 2025. It is educational, not legal or assessment advice. Last reviewed: 2026-09-22.
