What evidence do auditors commonly ask for on SC-20 Secure Name/Address Resolution Service (Authoritative)?

SSP SC-20 statement confirming DNSSEC signing of authoritative zones and provision of chain of trust for child zones; DNSSEC validation test results and DS records for each authoritative zone; Denial of service protection configuration and capacity test results; Boundary protection architecture with firewall and proxy rule documentation; Cryptographic standards specifying approved algorithms and key lengths; Key management procedures including rotation and escrow.

What is the most common gap auditors find on SC-20?

Cryptographic keys stored alongside the data they protect

FedRAMP Moderate (NIST SP 800-53 Rev 5 baseline) · SC - System and Communications Protection

`SC-20` Secure Name/Address Resolution Service (Authoritative)

Provide artifacts for additional data origin authentication and integrity verification (DNSSEC) for child zones; FedRAMP requires DNSSEC.

Source: FedRAMP Moderate (NIST SP 800-53 Rev 5 baseline), SC-20. The statement above is our statement of the clause, read from the published text and cited so you can check it against the official text, not the instrument verbatim. Open FedRAMP Moderate (NIST SP 800-53 Rev 5 baseline) in the compliance library.

A FedRAMP baseline is a subset of NIST SP 800-53 Rev 5, enhancements included.

artefacts

held by a system

at each review

moderate

to go live

Source control / CI pipeline

where the evidence lives

teal = a system already holds it · olive = produced at each review. To go live: easy when half or more of the artefacts are already held by a system, moderate from a quarter to a half, hard below a quarter.

These are the artefacts auditors commonly ask for on this requirement, our guidance rather than text from the standard. Your assessor decides what is sufficient in your context, and asks for samples across the period when a report covers one.

system holds itEvidence a system already holds

Denial of service protection configuration and capacity test results · Source control / CI pipeline
TLS configuration scan results across in scope endpoints · Vulnerability scanner / patch tooling

periodic reviewEvidence produced at each review

DNSSEC validation test results and DS records for each authoritative zone · Source control / CI pipeline

governing documentDocuments that govern the control

SSP SC-20 statement confirming DNSSEC signing of authoritative zones and provision of chain of trust for child zones · Document repository
Boundary protection architecture with firewall and proxy rule documentation · Policy repository / GRC workspace
Cryptographic standards specifying approved algorithms and key lengths · Policy repository / GRC workspace
Key management procedures including rotation and escrow · Policy repository / GRC workspace

First move

Start with the 2 of 7 artefacts that already live in a system (Source control / CI pipeline); keep the periodic reviews but log each one as a dated record with a named reviewer.

Common gaps auditors find

Cryptographic keys stored alongside the data they protect
Firewall rule base contains stale allow any entries
Internal traffic between services unencrypted within trusted zones
Legacy TLS versions remain enabled on external services

Do this for your whole sheet

Paste the rows you run your controls from and get this mapping for every control at once, with the periodic-review ones flagged and a first move per row. No account for the first run.

Build my evidence sheet

SC-18 Mobile Code · SC-21 Secure Name/Address Resolution Service (Recursive or Caching Resolver)