# System and Communications Protection Policy

**Template version:** 1.0.0 · **Baseline:** Moderate · **Edition:** Ready to adopt · **NIST basis:** SP 800-53 Rev. 5, release 5.2.0

*Tailor this template before adoption; it is not legal advice.* Latest version: <https://kston83.github.io/nist-guide/templates/policies/sc/>. Dedicated to the public domain under CC0 1.0 (<https://creativecommons.org/publicdomain/zero/1.0/>): adopt and change it without attribution.

## Purpose

This policy states what [Organization name] requires for System and Communications Protection, and who is accountable for meeting those requirements. (SC-1a.1(a))

## Scope

This policy applies at the [Select one or more: organization-level; mission/business-process-level; system-level. Typical: organization-level] to every system that [Organization name] owns or operates, or that is operated on its behalf, and to every person with access to those systems, including employees, contractors and partners. (SC-1a.1(a))

## Roles and responsibilities

- The [Chief Information Security Officer] is accountable for this policy and shall approve exceptions to it. (SC-1a.1(a))
- The [Fill in: an official to manage the system and communications protection policy and procedures. Typical: Chief Information Security Officer] shall manage the development, documentation and dissemination of this policy and its procedures. (SC-1b)
- Each [System owner] shall implement this policy for their system and document how in the system security plan. (SC-1a.1(a))
- Each person within scope shall follow this policy and report suspected violations to the [Chief Information Security Officer]. (SC-1a.1(a))

## Management commitment

The [Senior leader] approves this policy and shall provide the resources needed to implement it. (SC-1a.1(a))

## Coordination

The [Chief Information Security Officer] shall coordinate this policy with the legal, privacy, human resources and procurement functions, and with the owners of related policies, before each approval. (SC-1a.1(a))

## Compliance

- This policy shall be consistent with the laws, executive orders, directives, regulations, policies, standards and guidelines that apply to [Organization name], including [Fill in: laws, regulations and standards that apply to the organization]. (SC-1a.1(b))
- The [Chief Information Security Officer] shall review compliance with this policy through the organization's assessment and continuous monitoring activities. (SC-1a.1(a))
- An exception to this policy shall be requested in writing, approved by the [Chief Information Security Officer], time-limited and recorded with its compensating measures. (SC-1a.1(a))
- Violations of this policy shall be handled through the organization's sanctions process. (SC-1a.1(a))

## Procedures

The [Fill in: an official to manage the system and communications protection policy and procedures. Typical: Chief Information Security Officer] shall ensure that documented procedures exist to implement this policy and its associated controls. (SC-1a.2)

## Dissemination

- The [Fill in: an official to manage the system and communications protection policy and procedures. Typical: Chief Information Security Officer] shall disseminate this policy to [Fill in: personnel or roles to whom the system and communications protection policy is to be disseminated. Typical: everyone within its scope, through the policy library]. (SC-1a)
- The [Fill in: an official to manage the system and communications protection policy and procedures. Typical: Chief Information Security Officer] shall disseminate the procedures that implement this policy to [Fill in: personnel or roles to whom the system and communications protection procedures are to be disseminated. Typical: the people who carry them out, and the system owners]. (SC-1a)

## Policy statements

### Separation of system and user functionality (SC-2)

- The [System owner] shall ensure the system separates user functionality, including user interface services, from system management functionality. (SC-2)

### Information in shared system resources (SC-4)

- The [System owner] shall ensure the system prevents unauthorized and unintended information transfer through shared system resources. (SC-4)

### Denial-of-service protection (SC-5)

- The [System owner] shall ensure the system can [Select one: protect against; limit. Typical: protect against] the effects of the following types of denial-of-service events: [Fill in: types of denial-of-service events to be protected against or limited. Typical: network floods, protocol attacks and application-layer floods against internet-facing services]. (SC-5a)
- The [System owner] shall employ the following controls to achieve the denial-of-service objective: [Fill in: controls to achieve the denial-of-service objective by type of denial-of-service event. Typical: an upstream or cloud denial-of-service protection service for internet-facing services, rate limiting at load balancers and application gateways, and capacity that scales automatically]. (SC-5b)

### Boundary protection (SC-7)

- The [System owner] shall monitor and control communications at the external managed interfaces to the system and at key internal managed interfaces within the system. (SC-7a)
- The [System owner] shall implement subnetworks for publicly accessible system components that are [Select one: physically; logically. Typical: logically] separated from internal organizational networks. (SC-7b)
- The [System owner] shall connect the system to external networks or systems only through managed interfaces consisting of boundary protection devices arranged in accordance with the organization's security and privacy architecture. (SC-7c)

#### Federal systems

Federal civilian agencies secure their network connections under CISA's [Trusted Internet Connections (TIC) 3.0](https://www.cisa.gov/resources-tools/programs/trusted-internet-connections-tic) program, which implements OMB M-19-26, Update to the Trusted Internet Connections (TIC) Initiative (September 12, 2019). TIC 3.0 is set out in CISA's core guidance documents and use cases (as of September 2026).

- The [System owner] shall implement the system's external connections in accordance with the agency's TIC 3.0 architecture and the TIC 3.0 use cases that apply to the system. (SC-7c)

### Access points (SC-7(3))

- The [System owner] shall limit the number of external network connections to the system. (SC-7(3))

### External telecommunications services (SC-7(4))

- The [System owner] shall implement a managed interface for each external telecommunication service. (SC-7(4)(a))
- The [System owner] shall establish a traffic flow policy for each managed interface. (SC-7(4)(b))
- The [System owner] shall protect the confidentiality and integrity of the information transmitted across each interface. (SC-7(4)(c))
- The [System owner] shall document each exception to the traffic flow policy with the mission or business need that supports it and the duration of that need. (SC-7(4)(d))
- The [System owner] shall review exceptions to the traffic flow policy [Fill in: the frequency at which to review exceptions to traffic flow policy. Typical: at least annually, and when the system changes], and remove exceptions that an explicit mission or business need no longer supports. (SC-7(4)(e))
- The [System owner] shall prevent unauthorized exchange of control plane traffic with external networks. (SC-7(4)(f))
- The [System owner] shall publish information that enables remote networks to detect unauthorized control plane traffic from internal networks. (SC-7(4)(g))
- The [System owner] shall filter unauthorized control plane traffic from external networks. (SC-7(4)(h))

### Deny by default, allow by exception (SC-7(5))

- The [System owner] shall ensure network communications traffic is denied by default and allowed by exception [Select one or more: at managed interfaces; for [Assignment: organization-defined systems]. Typical: at managed interfaces]. (SC-7(5))

### Split tunneling for remote devices (SC-7(7))

- The [System owner] shall prevent split tunneling for remote devices connecting to organizational systems, except where the split tunnel is securely provisioned using these safeguards: [Fill in: safeguards to securely provision split tunneling. Typical: none; split tunneling is disabled for organization-managed remote devices]. (SC-7(7))

### Route traffic to authenticated proxy servers (SC-7(8))

- The [System owner] shall route [Fill in: internal communications traffic to be routed to external networks. Typical: outbound web traffic from internal users] to [Fill in: external networks to which internal communications traffic is to be routed. Typical: the internet] through authenticated proxy servers at managed interfaces. (SC-7(8))

### Transmission confidentiality and integrity (SC-8)

- The [System owner] shall ensure the system protects the [Select one or more: confidentiality; integrity. Typical: confidentiality and integrity] of transmitted information. (SC-8)

#### Federal systems

CISA [Binding Operational Directive 18-01](https://www.cisa.gov/news-events/directives/bod-18-01-enhance-email-and-web-security), Enhance Email and Web Security (October 16, 2017), requires that "All publicly accessible Federal websites and web services provide service through a secure connection (HTTPS-only, with HSTS)", that internet-facing mail servers offer STARTTLS, and that SSLv2, SSLv3, 3DES and RC4 are disabled on mail servers. CISA's directive page does not mark it revoked (as of September 2026).

- The [System owner] shall ensure each publicly accessible website and web service of the system provides service only through HTTPS, with HTTP Strict Transport Security. (SC-8)
- The [System owner] shall ensure each internet-facing mail server of the system offers STARTTLS. (SC-8)
- The [System owner] shall ensure SSLv2, SSLv3 and the 3DES and RC4 ciphers are disabled on the system's mail servers. (SC-8)

### Cryptographic protection (SC-8(1))

- The [System owner] shall implement cryptographic mechanisms to [Select one or more: prevent unauthorized disclosure of information; detect changes to information. Typical: prevent unauthorized disclosure of information and detect changes to information] during transmission. (SC-8(1))

### Network disconnect (SC-10)

- The [System owner] shall ensure the system terminates the network connection associated with a communications session at the end of the session or after [Fill in: a time period of inactivity after which the system terminates a network connection associated with a communication session. Typical: 30 minutes] of inactivity. (SC-10)

### Cryptographic key establishment and management (SC-12)

- The [System owner] shall establish and manage cryptographic keys, wherever the system employs cryptography, in accordance with [Fill in: requirements for key generation, distribution, storage, access, and destruction. Typical: the requirements for key generation, distribution, storage, access and destruction in the encryption and key management standard]. (SC-12)

### Cryptographic protection (SC-13)

- The [Chief Information Security Officer] shall determine the cryptographic uses for the organization's systems, which include [Fill in: cryptographic uses. Typical: encryption in transit and at rest, digital signatures and authentication]. (SC-13a)
- The [System owner] shall implement the following types of cryptography for each cryptographic use: [Fill in: types of cryptography for each specified cryptographic use. Typical: NIST-approved algorithms in cryptographic modules validated under FIPS 140-3 (or FIPS 140-2 for existing systems)]. (SC-13b)

#### Federal systems

[FIPS 140-3](https://csrc.nist.gov/pubs/fips/140-3/final) (March 22, 2019) "is applicable to all Federal agencies that use cryptography-based security systems to protect sensitive information", and modules validated under NIST's Cryptographic Module Validation Program (CMVP) are considered to conform to it (sections 6 and 9). The CMVP's [FIPS 140-3 transition page](https://csrc.nist.gov/projects/fips-140-3-transition-effort) sets the schedule for moving FIPS 140-2 validations to the Historical List in September 2026; modules on the Historical List remain supported for existing systems, but the standard notes that the Historical List "should not be used for procurement decisions" (as of September 2026).

- The [System owner] shall use cryptographic modules validated by the CMVP wherever the system uses cryptography to protect sensitive information. (SC-13b)
- The [System owner] shall select FIPS 140-3 validated modules for new systems and new purchases. (SC-13b)

### Collaborative computing devices and applications (SC-15)

- The [System owner] shall prohibit remote activation of collaborative computing devices and applications, with these exceptions: [Fill in: exceptions where remote activation is to be allowed. Typical: none, except conference room equipment that support staff activate for maintenance with the room owner's approval]. (SC-15a)
- The [System owner] shall ensure collaborative computing devices and applications give an explicit indication of use to users physically present at the devices. (SC-15b)

### Public key infrastructure certificates (SC-17)

- The [Chief Information Security Officer] shall ensure public key certificates are issued under [Fill in: a certificate policy for issuing public key certificates. Typical: the organization's certificate policy], or obtained from an approved service provider. (SC-17a)
- The [System owner] shall include only approved trust anchors in trust stores or certificate stores the organization manages. (SC-17b)

### Mobile code (SC-18)

- The [Chief Information Security Officer] shall define acceptable and unacceptable mobile code and mobile code technologies. (SC-18a)
- The [System owner] shall authorize, monitor and control the use of mobile code within the system. (SC-18b)

### Secure name and address resolution service (authoritative source) (SC-20)

- The [System owner] shall ensure the system provides additional data origin authentication and integrity verification artifacts along with the authoritative name resolution data it returns in response to external name and address resolution queries. (SC-20a)
- When the system operates as part of a distributed, hierarchical namespace, the [System owner] shall ensure it provides the means to indicate the security status of child zones and, if a child supports secure resolution services, to enable verification of a chain of trust among parent and child domains. (SC-20b)

### Secure name and address resolution service (recursive or caching resolver) (SC-21)

- The [System owner] shall ensure the system requests and performs data origin authentication and data integrity verification on the name and address resolution responses it receives from authoritative sources. (SC-21)

### Architecture and provisioning for name and address resolution service (SC-22)

- The [System owner] shall ensure the systems that together provide name and address resolution service for the organization are fault-tolerant and implement internal and external role separation. (SC-22)

### Session authenticity (SC-23)

- The [System owner] shall ensure the system protects the authenticity of communications sessions. (SC-23)

### Protection of information at rest (SC-28)

- The [System owner] shall ensure the system protects the [Select one or more: confidentiality; integrity. Typical: confidentiality and integrity] of [Fill in: information at rest requiring protection. Typical: all information stored by the system, including backups]. (SC-28)

### Cryptographic protection (SC-28(1))

- The [System owner] shall implement cryptographic mechanisms to prevent unauthorized disclosure and modification of [Fill in: information requiring cryptographic protection. Typical: all organizational information] at rest on [Fill in: system components or media requiring cryptographic protection. Typical: servers, databases, storage services, backups, end-user devices and removable media]. (SC-28(1))

### Process isolation (SC-39)

- The [System owner] shall ensure the system maintains a separate execution domain for each executing system process. (SC-39)

## Review and update

- The [Fill in: an official to manage the system and communications protection policy and procedures. Typical: Chief Information Security Officer] shall review and update this policy [Fill in: the frequency at which the current system and communications protection policy is reviewed and updated. Typical: annually] and following [Fill in: events that would require the current system and communications protection policy to be reviewed and updated. Typical: assessment or audit findings, security incidents or breaches, and changes in applicable laws, executive orders, directives, regulations, policies, standards or guidelines]. (SC-1c.1)
- The [Fill in: an official to manage the system and communications protection policy and procedures. Typical: Chief Information Security Officer] shall review and update the procedures that implement this policy [Fill in: the frequency at which the current system and communications protection procedures are reviewed and updated. Typical: annually] and following [Fill in: events that would require the system and communications protection procedures to be reviewed and updated. Typical: the same events as the policy, and changes to the systems, tools or services the procedures describe]. (SC-1c.2)

### Federal systems

For federal information systems, this policy also carries out the agency's information security responsibilities under the Federal Information Security Modernization Act of 2014 ([44 U.S.C. § 3554](https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title44-section3554&num=0&edition=prelim), Federal agency responsibilities) and [OMB Circular A-130](https://www.whitehouse.gov/wp-content/uploads/legacy_drupal_files/omb/circulars/A130/a130revised.pdf), Appendix I, Responsibilities for Protecting and Managing Federal Information Resources.

- Where the agency's organization-wide policy sets a value for a parameter in this policy, each system shall use that value or a stricter one. (SC-1a.1(b))