3.1.10Lock idle screens in Rev. 3
Reworded: 03.01.10 Device Lock. Gains organization-defined parameters.
Status as of 2026-09-08
Rev. 2 is what a contract requires today. DFARS 252.204-7012 and the CMMC rule at 32 CFR 170 point at NIST SP 800-171 Rev. 2, and a standing DoD class deviation keeps it there. NIST has published Rev. 3, but publishing a revision does not change an obligation. A move to Rev. 3 would arrive through the Department's reform process and formal rulemaking, a change to that deviation or an amendment to the rule, not through publication. The Department has published its organization-defined parameter values for Rev. 3 in preparation; that is groundwork, not adoption.
Side by side
Rev. 2 · in force 3.1.10 Session Lock
Assessment objectives · 800-171A
- [a] the period of inactivity after which the system initiates a session lock is defined
- [b] access to the system and viewing of data is prevented by initiating a session lock after the defined period of inactivity
- [c] previously visible information is concealed via a pattern-hiding display after the defined period of inactivity
Rev. 3 · not adopted 03.01.10 Device Lock
a. Prevent access to the system by [Selection (one or more): initiating a device lock after [Assignment: organization-defined time period] of inactivity; requiring the user to initiate a device lock before leaving the system unattended].
b. Retain the device lock until the user reestablishes access using established identification and authentication procedures.
c. Conceal, via the device lock, information previously visible on the display with a publicly viewable image.
Determination statements · 800-171A Rev. 3
- 03.01.10.a access to the system is prevented by <A.03.01.10.ODP[01]: SELECTED PARAMETER VALUES>.
- 03.01.10.b the device lock is retained until the user reestablishes access using established identification and authentication procedures.
- 03.01.10.c information previously visible on the display is concealed via device lock with a publicly viewable image.
Organization-defined parameters
- A.03.01.10.ODP[01] one or more of the following PARAMETER VALUES are selected: {a device lock is initiated after <A.03.01.10.ODP[02]: time period> of inactivity; the user is required to initiate a device lock before leaving the system unattended}.
- A.03.01.10.ODP[02] the time period of inactivity after which a device lock is initiated is defined (if selected).
Draws on Rev. 2 3.1.10.
Left: NIST SP 800-171 Rev. 2 and 800-171A, verbatim. Right: NIST SP 800-171 Rev. 3 and 800-171A Rev. 3, verbatim, with organization-defined blanks highlighted.
Word by word
The Rev. 2 requirement compared with its Rev. 3 successor. A mechanical comparison of the two verbatim texts, not an interpretation.
removed in Rev. 3 added in Rev. 3
Rev. 2 3.1.10 → Rev. 3 03.01.10 Device Lock
6 words kept, 12 removed, 59 added. Rev. 3 statement labels omitted for the comparison.
What NIST says changed
- New security requirement title
- Aligned with SP 800-53, Rev 5 to provide more comprehensive detail on and foundational tasks to implement device lock
- Terminology changed from "session lock" to "device lock"
- Added new ODP: select one or more ways to initiate device lock
- Added new ODP: time period to initiate device lock (if selected)
NIST, SP 800-171 Rev. 2 to Rev. 3 change analysis, class “Minor change”. At adoption, Bedrock files this under “Review”.
NIST's Rev. 3 discussion for 03.01.10
Device locks are temporary actions taken to prevent access to the system when users depart from the immediate vicinity of the system but do not want to log out due to the temporary nature of their absences. Device locks can be implemented at the operating system level or application level. User-initiated device locking is behavior- or policy-based and requires users to take physical action to initiate the device lock. Device locks are not an acceptable substitute for logging out of the system (e.g., when organizations require users to log out at the end of workdays). Publicly viewable images can include static or dynamic images, such as patterns used with screen savers, solid colors, photographic images, a clock, a battery life indicator, or a blank screen with the caveat that controlled unclassified information is not displayed.
What this means for you now
Nothing changes in what you are assessed against until a class deviation or a published rule adopts Rev. 3. Keep meeting 3.1.10 as written in Rev. 2, and if you already choose a value for the parameters above in practice, write it down where your system security plan can find it.
Bedrock CMMC shows this same comparison against your own package, with your current status on the Rev. 2 side, so the day adoption lands the migration is a review, not a rewrite.
Where this page's facts come from
- Rev. 2 text and objectives
- bedrock-cmmc-api@89b8e8e:migrations/004_reference_requirements.sql#Requirement.basicRequirement@rev2; bedrock-cmmc-api@89b8e8e:migrations/005_reference_objectives.sql#AssessmentObjective.description@rev2
- Mapping and change class
- bedrock-cmmc-api@89b8e8e:docs/reference/nist-800-171-rev3/normalized/r2_r3_transition_map.json#r2_to_r3
- Rev. 3 03.01.10
- bedrock-cmmc-api@89b8e8e:docs/reference/nist-800-171-rev3/normalized/rev3.json#requirements[]