SC-37 Out-of-band channels: requirements and evidence

What SC-37 out-of-band channels requires and when it applies

An authorizing official or a contract clause has asked you to address SC-37, and you have checked the baselines and found it in none of them. That is expected. SC-37 is not selected by the SP 800-53B low, moderate, high or privacy baseline, so it reaches your system only when your organization chooses it through tailoring or an overlay. Your first task is to confirm who asked for it, which system it must cover, and whether the request comes from a baseline, a contract or an agency-specific overlay. Only then does the control become a requirement you must design for.

In plain terms, an *out-of-band channel* is a route for delivering something that is kept separate from the normal network the system uses for everyday traffic. The control asks you to define those channels and then use them for defined information, components or devices sent to defined individuals or systems. Examples include a sealed courier delivering a cryptographic key, a separately administered portal for a patch or a dedicated phone verification for a credential reset. The risk it addresses is simple: if an attacker controls or can observe the ordinary network, a key, password or update delivered over that network can be intercepted or replaced. A separate path makes that interception much harder.

Defining the channels and their parameters is usually the hard part. SC-37 has three organization-defined parameters, and each must be filled with specific content: which channels exist, what information or components travel over each, and to whom. Expect the assessor to ask for the list of channels, the physical delivery and electronic transmission records and the system design documentation that shows the channels are used. Start by listing every item the system receives through an out-of-band path today, including ones handled informally. Then confirm with the control owner that each channel is independent of the network it protects. Your implementation partner can help prepare that inventory and the records, but the organization must decide what counts as out-of-band for its own risk.

Which systems, keys and third parties SC-37 scopes in

SC-37 leaves most of its substance to the organization: it has defined parameters for what travels out of band, to whom, and through which channels. The cards below cover the decisions that shape the control's scope, and each one should be settled and documented before anyone designs a delivery process.

Cryptographic keys and certificates

Decide whether root keys, signing keys, key-encryption keys or initial enrollment secrets must move outside the production network. Each key class carries a different blast radius if intercepted. For each one, record who generates it, which channel carries it, and who is authorized to receive it. Confirm that the key management design in SC-12 matches this list, so the same key is not defined two different ways in two control records.

Administrative and privileged credentials

Bootstrap passwords, break-glass accounts and recovery codes for administrative consoles are common candidates for an out-of-band channel. The scope question is which credentials cannot safely travel over the network they protect. Map each one to the systems it unlocks, then check whether the same channel also serves the identity controls in IA, so credentials are not delivered through a path the identity system itself depends on.

Patches, firmware and hardware components

Decide which software updates, firmware images and hardware components need separate delivery. Firmware and boot components are the usual cases, because a compromised update channel can alter the device before any endpoint control runs. For each item, define the target devices, the integrity check performed on arrival, and the record that shows the component reached the intended system unchanged.

Receiving systems and individuals

Define the systems and named individuals who may receive each category of item. A parameter that says only "authorized personnel" will be hard to test. List the receiving roles, the systems they can receive material for, and how receipt is confirmed. Assessors look for a list that matches the people and hosts that actually take delivery, so keep it aligned with the access records maintained under AC-2.

Couriers, suppliers and delivery agents

Physical delivery of media, tokens or hardware often passes through couriers, freight forwarders or a vendor's own logistics team. Each external party becomes part of the control's scope. Identify who handles the item between sender and recipient, what contractual terms cover their handling, and how tampering or loss is detected. Supplier obligations should be reflected in the SR and SA records for the same relationship.

Channel and transmission records

Once the items are chosen, document the channels themselves: physical courier routes, separate network paths, or dedicated telephone or in-person verification. Assessors examine the list of out-of-band channels and the delivery records together. Confirm that every channel in the list is actually used, and that every item in the scope has a documented channel, because gaps between the two lists are a common finding.

How an assessor tests SC-37 under SP 800-53A

This table breaks down the single SP 800-53A determination statement for SC-37 by assessment method and object. Use it to see what an assessor asks to examine, whom they interview and where out-of-band delivery programs most often fail the test.

Assessment element	What the assessor does	Evidence the assessor expects	Common finding
Determination statement	Confirms that the organization has defined the out-of-band channels, the information, components or devices sent through them, and the recipients, then checks that the defined channels are used	A written definition of each channel, what it carries and who receives it, approved by the owner of the control	Channels are used in practice but never written down, so there is nothing to test against
Examine: list of out-of-band channels	Reads the channel list and checks that each entry names the channel type, the content it carries and the permitted recipients	Current channel register with owner, approval date and review history	Register is out of date and lists channels that no longer exist
Examine: physical delivery records	Samples shipments or hand-offs of keys, credentials or devices and traces each one to a listed channel	Courier logs, chain-of-custody forms, sealed-package records and recipient signatures	Deliveries go by a route that does not appear in the channel list
Examine: electronic transmission records	Samples electronic deliveries, such as credential or patch distribution, and checks that they used the defined separate path	Transmission logs, channel configuration exports and records of the recipient's confirmation	Credentials are sent through the production network or email, which the channel list does not cover
Examine: system design documentation	Reviews architecture and data flow diagrams to confirm the separate channels exist and are isolated from the normal network	Data flow diagrams, network diagrams and configuration of the separate path	Diagrams omit the out-of-band path, so the design does not match the operating system
Interview	Asks system owners, delivery staff and recipients how they actually send and receive keys, credentials and components	Consistent answers from several roles and a walkthrough of one real delivery	Staff describe informal workarounds that the documents do not mention
Test	Attempts or observes a delivery through a listed channel and checks that the content and recipient match the record	Witnessed delivery, verification of the recipient and comparison with the transmission or shipping log	Records show the delivery, but the recipient cannot be verified against the defined list
Reconciliation across records	Compares the channel list, delivery records and design documents for gaps	Matching identifiers across the three sources	Delivery records do not match the list, so the assessor cannot conclude the control is met

Implementing SC-37 step by step

This sequence turns SC-37 from a control name into a selected, parameterized and documented set of out-of-band delivery paths that an assessor can trace from decision to recorded delivery. Each step produces an artifact the organization owns, so the control can be tested rather than asserted.

Confirm SC-37 is selected through tailoring
Start by checking whether SC-37 is in your system's baseline. SP 800-53B does not assign SC-37 to the low, moderate, high or privacy baseline, so it enters scope only when the system owner selects it during tailoring or an overlay adds it. The system security official, with the authorizing official's input, records the decision and the reason, such as a specific threat to key or patch delivery. Output: a tailoring decision entry in the system security and privacy plan that states SC-37 is selected or deliberately excluded, with its rationale. If an overlay or contractual requirement already names SC-37, record that source instead. Where SC-37 is not selected, the step still closes with a documented exclusion so an assessor sees the decision was made.
Define the organization-defined parameters
SC-37 carries three organization-defined parameters, which the organization must fill in before any assessment can pass. Security architecture and operations staff, working with the system owner, define the information or components or devices to be delivered, the out-of-band channels available, and the defined individuals or systems that receive them. Keep each parameter specific enough to test, for example naming the category of key material or patch bundle rather than saying sensitive items. Output: a parameter table with one row per parameter, its values, the owner who approved it, and the date it was last reviewed. Ask whether the assessment object list matches these values, since SP 800-53A examines the list of out-of-band channels directly.
Inventory the delivery paths in use
Before choosing channels, list every way that keys, credentials, patches or components currently reach the system. Include routine paths such as configuration management tooling, package repositories, email, file shares, ticketing attachments, vendor portals and physical media handling. Operations engineers walk through real delivery events from recent change records rather than relying on memory. Output: a delivery path inventory listing each path, the item types it carries, the systems that send and receive, and whether the path normally shares the production network. This inventory is the baseline that the channel mapping in the next step uses, and it often reveals paths that were never documented.
Map each delivery path to an out-of-band channel
For every item type covered by the parameters, decide which channel delivers it and confirm that channel is separate from the network path the item would otherwise travel. A channel can be physical, such as a sealed courier, a hardware token sent by a separate carrier, or a secure key ceremony with witnesses, or electronic, such as a second network, a separate identity path or a call-back verification over a different medium. Security engineering documents the reason each channel is independent of the compromised path it replaces. Output: a channel mapping matrix that links each item type and recipient to one channel and its independence rationale. Flag any item type with no separate channel as an open gap for the system owner to accept or fix.
Document the delivery and transmission procedure
Write the step-by-step procedure for each mapped channel: who initiates delivery, how the item is packaged or encrypted, how the recipient is verified, what happens when delivery fails, and how an item that arrives unexpectedly is handled. Include verification steps such as confirming the recipient through a previously established contact method, not one that came with the item. The operations team and the security officer both approve the procedure, and the document goes under configuration control. Output: a versioned delivery procedure with an approval record, and a short checklist operators can follow during an actual delivery. Assessors use this document to test the examine objects for documentation, so keep it consistent with the channel matrix.
Train and assign delivery roles
Assign named roles for sending, receiving and verifying each channel, and make sure the people holding those roles have been briefed on the procedure. Separate the sender from the verifier where the organization's risk assessment calls for it. Record training completion and role assignments in the system's records, because interviews during SP 800-53A assessment often test whether personnel know the procedure. Output: a role assignment list and training acknowledgments tied to the procedure version. Confirm with your assessor what evidence of training they will accept, since the expected form varies by organization and by the assessment plan.
Record each delivery and test the channel
Every out-of-band delivery produces a record: item, sender, recipient, channel, date, verification method and outcome. Keep these records in a system that protects their integrity, since they are the physical delivery records and electronic transmission records that assessors examine. Periodically exercise each channel with a test delivery, and review a sample of past deliveries against the procedure to find drift. Output: a delivery log, test results for each channel, and a finding register entry for any delivery that did not follow the procedure. The step closes when a sampled delivery can be traced end to end from the decision in step one to the recorded outcome.

How a separate channel stops a compromised network from intercepting keys

The point of SC-37 is that the channel carrying a sensitive item should not be the same channel an attacker can already see or alter. If the network is compromised, any key, credential, patch or component sent over it can be read, replaced or redirected. An out-of-band channel moves that item through a path the compromised network does not control, such as a physical courier, a separately administered portal or a call-back verification to a known number. The control requires the organization to define which channels exist, what each one carries and to whom, so the design decision is made before an incident rather than during one.

Illustrative example, hypothetical: an administrator needs a new break-glass credential for a self-hosted identity platform. The organization sets the password reset through the normal admin portal, but the initial secret is sent by a sealed letter couriered to the security lead, while the activation code is read back by phone to a number held in a separate directory. An attacker who has taken over the email and VPN path can still see the portal traffic, yet cannot receive the courier package or answer the call-back. The reader should confirm that every out-of-band channel in their design is actually independent of the channel it verifies, since two channels that share an identity provider or mail relay offer little protection.

SC-37 sits next to several related controls in the catalog, and the relationship is one of neighboring design decisions rather than a mapping. SC-12 covers key generation, distribution and destruction, IA-5 covers authenticator management, SI-7 covers integrity verification of software and information, and MA-4 covers nonlocal maintenance. A practical check is to list each key, credential, patch or component that the organization delivers, then note which of these related controls already governs it and where SC-37 would add a separate delivery path. Assessors will expect that list to exist, so confirm with your assessor how they want the defined channels and their records documented.

Evidence that passes an SC-37 assessment

SP 800-53A assesses SC-37 through a single determination statement, and the examine objects point to four artifact types: the list of defined channels, physical delivery records, electronic transmission records and system design documentation. The cards below cover what each artifact must show and how to keep it current between assessments.

Register of defined out-of-band channels

This is the list of channels the organization has defined for delivering information, components or devices, with the parameters set for each. Assessors check that every channel named in the register matches what the system design and delivery records show. For each entry, record the channel type, the sender and recipient roles, the information or components it may carry, and the verification step used on receipt. Confirm that the register is the single source the other artifacts reference.

Physical delivery records

These records show that a defined channel was used for a physical delivery, such as a key fob, hardware token, media or a signed patch package carried by courier. Each record should capture the item, the sending and receiving individuals, the channel used, dates, and the tamper or seal check performed at receipt. Compare records against the register to find deliveries made through channels that were never defined. Illustrative example: a courier log that names a channel not listed in the register is an exception to raise before the assessment.

Electronic transmission records

For electronic channels, such as a separate management network, a dedicated file transfer path or an out-of-band console, the evidence is the transmission log showing the channel, the endpoints, the time and the item transferred. Logs from the components that carry the traffic are stronger than a manual record. Check that the logs show the channel was separate from the normal production network, and that the transfer was verified, for example by hash comparison against the value the sender published. Confirm which log sources your platform writes to and how long they are retained.

System design documentation

The design documents show where each out-of-band channel sits in the architecture, which network paths and access controls separate it from the normal network, and which systems can use it. Assessors use them to test whether a channel is truly independent. Keep diagrams, network segmentation rules and access lists under version control, and link each channel in the register to the diagram that shows it. A design change that adds a path should trigger an update to both the diagram and the register.

Keeping evidence current between assessments

Evidence goes stale when a channel is added, retired or re-routed without a matching update. Set a recurring review of the register and design documents, and tie any change to the configuration change process so that new channels cannot appear without a register entry. Keep delivery and transmission records for the period the organization's own policy sets and confirm the period with the assessor before the assessment. Review the register against the system's actual routes at least once in each review cycle.

Sign-off and change ownership

Name one owner for the register and assign approval of each change to the system owner and the security function, with the security function holding the final approval for new channels. Record the approver, the date and the reason in the change ticket. Separate the people who request a delivery from the people who approve the channel definition where staffing allows. Confirm with the assessor how sign-off is expected to be documented, since the assessment procedure does not prescribe a format.

What meeting SC-37 costs in money and effort

This table breaks down the cost and effort components of implementing SC-37 Out-of-band channels, showing who is paid for each, whether it is one-time or recurring, and what drives it. No price figures are supplied for these items, so use the right-hand column to decide what to request in a written scope or quote from each party.

Cost component	One-time or recurring	What drives it, and what to request in a quote
Engineering time to define channels and parameters	One-time, revisited on change	Number of out-of-band channels and the three organization-defined parameters. Request a named list of channels, the information or components each carries, and the recipients.
Procedure and delivery record upkeep	Recurring	Frequency of out-of-band deliveries and how many systems are involved. Ask who maintains the procedures and records, and in what system they are kept.
Courier or secure physical delivery services	Recurring, per delivery	Whether any channel is physical, its geography and the delivery volume. Ask the provider for its written service terms and what evidence of handover it returns.
Channel design review by an outside party	One-time, repeated on material change	Complexity of the channel design and independence required by your assessor. Confirm with the assessor whether they expect an external review and what it must cover.
Secondary channel infrastructure and verification tooling	One-time build, recurring operation	Whether a separate network path or verification method (such as confirmation by a second channel) must be stood up and maintained. Confirm the technical design with your architects before scoping.
Auditor sampling and evidence preparation	Recurring, each assessment cycle	Number of deliveries the assessor samples and how easily records can be retrieved. Ask the assessor how many samples they will take and which evidence they will request.
Implementation partner support	One-time, with optional retainer	Fixed-scope work to design, document and test channels, plus any ongoing support. Ask for written deliverables, timelines and what is excluded from scope.

Who owns SC-37, who helps and what the auditor checks

Your organization owns SC-37. The control requires you to define the out-of-band channels, define what information, components or devices move through them, and define the individuals or systems that receive them. Those are management decisions, and an assessor will expect to see them recorded as the organization's own decisions rather than as vendor defaults. Because the control is organization-defined, the parameter choices are where most of the real work sits.

Channel definitions: Name each out-of-band channel (for example, a separate phone verification path, a courier process or a separate management network) and state its purpose.
Delivery decisions: Decide which keys, credentials, patches or components use which channel, and who authorizes each delivery.
Recipient lists: Maintain the defined individuals or systems allowed to receive each item.
Delivery records: Keep physical delivery records and electronic transmission records that show what was sent, when, by which channel and to whom.
Tailoring rationale: Document why SC-37 is selected for your system, since it is not in a baseline.

Confirm with your own assessor which parameter values they will accept before you finalize the channel list.

Where organizations fall short on out-of-band delivery

Most SC-37 gaps are documentation gaps rather than engineering gaps. The channels exist in practice, but nobody has listed them, tied them to specific information or components, or kept records that an assessor can sample. The cards below cover the failure points we see most often and how to close each one.

Channels never listed

SC-37 requires the organization to define its out-of-band channels, so an undocumented courier, sealed-envelope process or separate maintenance network does not count. Start by inventorying every route used to hand keys, credentials, patches or hardware to people or systems outside the normal network. For each route, record the channel type, the owner, the approved senders and recipients, and the information classes it may carry. Assessors will compare this list against what staff describe in interviews, so gaps show up quickly.

Delivery records absent

The examine methods for SC-37 look for physical delivery records and electronic transmission records. When a key or patch goes out by courier, a sealed envelope or a separate channel, the sender and receiver should each leave a record of what was sent, when, to whom and how it was verified on receipt. Many teams keep these in email threads or personal notes. Set up a delivery log, with a ticket or form per transfer, and confirm that its retention meets your own policy.

Same path for normal and out-of-band traffic

An out-of-band channel only protects against interception if it is actually separate from the path that carries routine traffic. Teams sometimes send an emergency credential through the same corporate email, the same VPN or the same file share used for everyday work, which defeats the purpose. Map each channel to the network, identity provider and mail system it depends on, and confirm that a compromise of the production path cannot reach it. Where a dependency is shared, document the residual risk and the compensating checks.

SC-37 selected without documented parameters

SC-37 has organization-defined parameters, so selecting the control without filling them in leaves it untestable. The parameters name the channels, the information, components or devices, and the recipients. An assessor who finds a selected control with blank parameters will usually record it as not implemented. Before the next assessment, confirm the values in the system security plan, check that each one matches the channel inventory, and record who approved them and when they were last reviewed.

Verification of received items skipped

A channel only helps if the recipient can confirm that what arrived is what was sent. Common gaps include accepting a key or patch without checking its hash or signature, and accepting a call from someone claiming to be the sender without a callback to a known number. Define the verification step for each channel, such as comparing a fingerprint through a second channel or confirming a shared phrase in person, and record the result alongside the delivery entry.

Related controls left out of scope

The catalog links SC-37 to controls such as SC-12 on key management, SI-7 on integrity verification and IA-5 on authenticator management. Organizations that treat SC-37 as a standalone procedure often miss that these controls define what the out-of-band channel carries and how the item is protected once received. Review the twelve related controls listed for SC-37, identify which ones apply to your channels, and make sure the same evidence supports both.

Questions buyers ask about SC-37

Is SC-37 required in a moderate baseline or a FedRAMP baseline?

No. SP 800-53B does not assign SC-37 to the low, moderate, high or privacy baseline, so it applies only when your organization selects it through tailoring or an overlay. FedRAMP's Rev5 baselines do not require SC-37 at Class B, C or D, according to the FedRAMP Rev5 control reference for the System and Communications Protection family. Appendix C of SP 800-53 Rev. 5 still lists it as an organization-implemented, assurance-related control, so a contract or internal policy can pull it in. Check the baseline your system is authorized against and any overlay your contract cites before assuming it is out of scope. Your assessor will expect a documented decision either way.

What does SC-37 actually ask an organization to have in place?

SC-37 asks you to define the out-of-band channels you use to physically deliver or electronically transmit defined information, components or devices to defined individuals or systems. In practice, that means naming each channel (for example, a separate courier process for hardware tokens or a dedicated path for emergency credential release), stating what travels through it, and naming who may send and receive. The control has three organization-defined parameters and one enhancement in Release 5.2.0. Your team owns those definitions and the process behind them. Nothing in the control requires a specific product.

Can our own team implement SC-37 without outside help?

Usually yes, because the control is mostly documentation, process design and records rather than engineering. Your security, operations and facilities staff can define the channels, write the procedures and keep delivery logs. Outside help is most useful when channels touch identity systems, key management or automated patch delivery, where the design needs to be tested against real failure modes. An implementation partner such as DeployOpen can prepare systems and evidence for your assessment, but the organization owns the control and only an independent assessor can issue findings or a report.

What evidence will an assessor ask to see for SC-37?

SP 800-53A Release 5.2.0 assesses SC-37 through one determination statement, using examine, interview and test methods. The suggested examine objects include the list of out-of-band channels, physical delivery records, electronic transmission records and system design documentation. Expect to show the channel register with its parameters filled in, the procedures for each channel, sample delivery and receipt records, and diagrams showing how each channel sits apart from the normal network. Interviews will check that the people who send and receive know the procedure. Keep these records current, because an assessor will sample across a period rather than accept a single snapshot.

How long does it take to prepare SC-37 evidence?

No duration is set by NIST for this control, and the answer depends on how many channels you use and how well delivery is already logged. Teams with a single documented courier or break-glass process usually need less time than teams that run several channels with no records. Ask any partner to break the work into channel inventory, procedure writing, record design, a sample run and evidence collection, and to tie each phase to a written scope. Treat any single duration offered without that breakdown as a sales estimate rather than a plan.

What drives the effort and cost of meeting SC-37?

The biggest driver is the number of channels and the number of defined parameters, since each channel needs its own definition, owner, procedure and records. Effort also rises when channels cross facilities, vendors or cloud accounts, and when they carry high-impact items such as root credentials or firmware. Costs are split between internal staff time, which recurs as deliveries happen, and any external work, which is usually one-time for design and may recur if you retain support. NIST does not estimate compliance costs, so ask any provider to price the channel count, record keeping and assessor support separately in a written quote.

Which parts of SC-37 are usually outsourced, and which should stay in-house?

Keep ownership of the channel register, the decision on which channels are trusted, and the approval of who may send and receive sensitive items. These are accountability decisions that an assessor will attribute to your organization. Outsourcing is common for the technical build, such as configuring a separate administrative network, a hardened delivery host or a signed-package workflow, and for drafting procedures and evidence packs. Any external party can prepare materials, but only an independent assessor or certification body issues an assessment outcome.

Where self-hosted open-source platforms help with SC-37

Self-hosted open-source platforms help most with the records an assessor will ask for under SC-37: the list of defined out-of-band channels, the physical delivery records and the electronic transmission records. The platforms do not make a channel out of band. Your organization decides which channels qualify, which keys, credentials, patches or components use them, and which individuals or systems receive them. A platform can then hold the inventory of those decisions and the logs that show each delivery followed them. In practice, configuration management and version-controlled repositories can store the channel list, the approved recipients and the rules for each channel as reviewed files, so every change carries an author, a reviewer and a date. Configuration records of the systems that receive out-of-band material, such as the hosts that accept a key or a patch, can be exported on a schedule and compared against the defined baseline. Ask your team which of these records already exist, who owns each one, and whether they can be produced without manual reconstruction during an assessment. The weakest point is usually the link between a delivery and the channel it used. Confirm with your engineers whether your ticketing, artifact or secrets tooling records the channel, the sender, the recipient and the hash or identifier of what was delivered, and whether those entries are retained and protected from editing. Check the tooling against the specific examine objects in SP 800-53A rather than assuming a generic audit log covers them, and confirm every capability with the vendor or project in your own environment before you rely on it.

Where to read the SC-37 text and assessment procedure

This sequence takes you from the official SC-37 control text to its baseline status and assessment procedure, so you know exactly what an assessor will check before you scope any out-of-band work. Each step ends with a specific check you can record in your own scoping notes.

Open the Release 5.2.0 OSCAL catalog for SC-37
Start with the NIST OSCAL catalog for SP 800-53 Rev. 5 in the usnistgov/oscal-content repository, which holds the current Release 5.2.0 controls in machine-readable form. Locate the SC family and find SC-37 Out-of-band channels. Read the control statement and note its three organization-defined parameters and its single control enhancement, because each parameter must be filled in by your organization before the control can be tested. The step is complete when you have copied the control ID, title and parameter list into your scoping notes with the release number beside them.
Check the SP 800-53B baseline profiles
Open the SP 800-53B profiles for the low, moderate, high and privacy baselines in the same OSCAL repository, and search each one for SC-37. SP 800-53B does not assign SC-37 to any security or privacy baseline, so it will not appear in those profiles. Record that result, because it means SC-37 applies only if your organization selects it through tailoring or an overlay, or if a contract or authorizing body names it. The step is complete when you have a written note confirming the baseline status for each profile you checked.
Confirm the FedRAMP Rev5 position
Open the FedRAMP Full Rev5 control reference for the System and Communications Protection family to confirm how FedRAMP treats SC-37 in its Rev5 baselines. If you operate a cloud service or serve federal customers, this reference is the authority your sponsor or assessor will rely on. Compare its entry with the SP 800-53B result from the previous step. The step is complete when you have recorded whether SC-37 is required for your FedRAMP impact level, or confirmed that it is not, and noted the reference date.
Read the SP 800-53A assessment procedure
Open SP 800-53A Release 5.2.0 and find the SC-37 assessment procedure, which is published alongside the control in the OSCAL content. The procedure contains one determination statement and lists examine, interview and test methods with suggested assessment objects. Read the examine objects closely, since they name the evidence an assessor expects, including the list of out-of-band channels, physical delivery records, electronic transmission records and system design documentation. The step is complete when you have mapped each examine object to a document or system record your organization can produce.
Review the related controls in the catalog
In the SC-37 entry of the Release 5.2.0 catalog, review the twelve related controls, which include access, configuration, identification and authentication, maintenance, key management, system integrity and monitoring controls. Each related control indicates where an out-of-band delivery path touches an existing control that an assessor may also test. Mark the related controls that already have owners and evidence in your program. The step is complete when you have a list of related controls, each assigned to a control owner or flagged as a gap.
Confirm scope and ownership with your assessor
Take your notes from the previous steps to your authorizing official, compliance lead or independent assessor, and confirm whether SC-37 is in scope and which parameter values they expect. Ask them to confirm the release of SP 800-53 they will use, since the catalog has been revised over time. Only the organization can decide scope and accept the risk, and only an independent assessor issues the finding. The step is complete when the scope decision and the parameter values are recorded in writing with the date of the decision.

How DeployOpen scopes SC-37 for self-hosted platforms

SC-37 is not in any SP 800-53B baseline, so it usually enters a program only through tailoring or an overlay. DeployOpen's role is to plan and document the delivery paths for self-hosted platforms in your own infrastructure, then prepare the procedures and evidence an assessor will ask to see.

Confirm whether SC-37 applies

Start by checking whether SC-37 is in your selected baseline or overlay, since SP 800-53B does not assign it to any baseline. If it is not selected, the scoping decision should be recorded with its rationale. If it is selected, the organization must define which information, components or devices move out of band, and to whom. DeployOpen can document that decision as part of a fixed-scope plan, but the decision and its risk acceptance remain with your organization.

Map delivery paths for self-hosted platforms

For each item in scope, such as a key ceremony, a credential handoff, a patch bundle or an offline component, document the sender, receiver, channel and verification step. Separate paths are typically defined for physical media and for electronic transmission. DeployOpen maps these paths against your own cloud accounts, data centers or air-gapped networks, so the documented route matches what the platform actually uses.

Define the out-of-band channel register

The examine objects for SC-37 include a list of out-of-band channels, so assessors expect a written register. It should name each channel, its owner, the data classes it carries and the controls protecting it. Keep the register under change control with the rest of the system documentation so that a new delivery path cannot appear without review.

Prepare transmission and delivery records

Physical delivery records and electronic transmission records are named evidence for SC-37. Design the logging so each out-of-band delivery captures the item, the recipient, the time, the channel used and the verification performed. Confirm with your assessor which record format they accept and where those records must be retained.

Test the independence of each channel

The purpose of an out-of-band channel is that a compromise of the normal network cannot intercept the item. Test whether each alternate path shares identity providers, DNS, certificate authorities or jump hosts with the production network. Where it does, record the shared dependency as a risk and decide with the control owner whether it is acceptable.

Hand over evidence and assessment limits

DeployOpen prepares procedures, configurations and evidence packages, but does not issue assessment results. Only an independent assessor or auditor can test SC-37 and report on it. Before work starts, ask for the written scope, deliverables and the timeline agreed in it, since a quote follows from that scope and retainers can cover later changes.