# SC-20 Secure Name/Address Resolution Service (Authoritative Source) — NIST 800-53 Rev5 control

> FedRAMP Consolidated Rules for 2026 v2026.07.14.01 · updated 2026-07-14
> Canonical page: /control/sc-20

Canonical id: `sc-20` · family `SC`

> a. Provide additional data origin authentication and integrity verification artifacts along with the authoritative name resolution data the system returns in response to external name/address resolution queries; and b. Provide the means to indicate the security status of child zones and (if the child supports secure resolution services) to enable verification of a chain of trust among parent and child domains, when operating as part of a distributed, hierarchical namespace.

_Control title and statement: NIST SP 800-53 Rev5 catalog (the pinned commit is in `/api` under `control_text`). The FedRAMP rules reference these controls by id only; everything below is what FedRAMP says about this id._

## Rev5 baseline membership

- certification class B
- certification class C
- certification class D

## Key Security Indicators that reach it

- `KSI-IAM-ELP` — Ensuring Least Privilege (Identity and Access Management)
  Identity and access management measures are used and persistently reviewed to ensure each user or device can only access the resources they need.
- `KSI-SVC-SIN` — Securing Information (Service Configuration)
  Information is encrypted or otherwise secured from unwanted access or modification.

## FedRAMP guidance

_No FedRAMP-specific guidance attaches to this control._