SC-13 Cryptographic Protection

Guidance: draftPolicy clause: draftWhat these mean

Baselines	Implementation level	Enhancements
Low, Moderate, High	System	None

Related controls: AC-2, AC-3, AC-7, AC-17, AC-18, AC-19, AU-9, AU-10, CM-11, CP-9, IA-3, IA-5, IA-7, IA-13, MA-4, MP-2, MP-4, MP-5, SA-4, SA-8, SA-9, SC-8, SC-12, SC-20, SC-23, SC-28, SC-40, SI-3, SI-7

Control statement

• a. Determine the [Assignment: organization-defined cryptographic uses] ; and
• b. Implement the following types of cryptography required for each specified cryptographic use: [Assignment: organization-defined types of cryptography].

NIST discussion

Cryptography can be employed to support a variety of security solutions, including the protection of classified information and controlled unclassified information, the provision and implementation of digital signatures, and the enforcement of information separation when authorized individuals have the necessary clearances but lack the necessary formal access approvals. Cryptography can also be used to support random number and hash generation. Generally applicable cryptographic standards include FIPS-validated cryptography and NSA-approved cryptography. For example, organizations that need to protect classified information may specify the use of NSA-approved cryptography. Organizations that need to provision and implement digital signatures may specify the use of FIPS-validated cryptography. Cryptography is implemented in accordance with applicable laws, executive orders, directives, regulations, policies, standards, and guidelines.

Withdrawn enhancements: SC-13(1), SC-13(2), SC-13(3), SC-13(4).

Assessment objectives (SP 800-53A)

Objectives and methods for SC-13

Determine if:

• SC-13a. [Assignment: organization-defined cryptographic uses] are identified;
• SC-13b. [Assignment: organization-defined types of cryptography] for each specified cryptographic use (defined in SC-13_ODP[01]) are implemented.

Examine: System and communications protection policy; procedures addressing cryptographic protection; system design documentation; system configuration settings and associated documentation; cryptographic module validation certificates; list of FIPS-validated cryptographic modules; system audit records; system security plan; other relevant documents or records.

Interview: System/network administrators; organizational personnel with information security responsibilities; system developer; organizational personnel with responsibilities for cryptographic protection.

Test: Mechanisms supporting and/or implementing cryptographic protection.

Policy statement

• 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 (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 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)

From the System and Communications Protection Policy template (draft). Highlighted fields are values your organization sets.

How to apply it

SC-13 asks you to decide where the system uses cryptography and which kind of cryptography each use requires. It does not require cryptography by itself; controls such as SC-8, SC-28, IA-5 and AC-17 do. SC-13 sets the standard that cryptography must meet wherever those controls call for it.

Common implementations. A cryptography standard listing each use (data in transit, data at rest, digital signatures, hashing, key exchange, authentication) and the approved algorithms, key lengths and modules for each. Validated cryptographic modules, usually the ones built into operating systems, cloud key management services and hardware security modules, run in their approved mode. A cryptographic inventory showing where each algorithm is used, which also prepares the system for the move to post-quantum algorithms such as FIPS 203 (August 13, 2024), with FIPS 204 and FIPS 205.

Organization-defined parameters. Typical values, which your organization may set differently:

Parameter	Typical value
Cryptographic uses (a)	Encryption in transit and at rest, digital signatures and authentication
Types of cryptography for each use (b)	NIST-approved algorithms in cryptographic modules validated under FIPS 140-3 (or FIPS 140-2 for existing systems)

Evidence assessors ask for.

• The cryptography standard naming uses, algorithms and modules
• Validation certificate numbers for the modules in use, from the NIST Cryptographic Module Validation Program
• Configuration showing modules run in their approved mode, where this is a setting
• The cryptographic inventory

Inheritance. Cloud providers and operating system vendors supply the validated modules; confirm the provider’s validation covers the services you use. The system owns its choice of algorithms and any cryptography inside its own code.

Common findings.

• Claims of “FIPS validated” with no certificate number, or a certificate that does not cover the module version in use.
• Application code using its own or an unvalidated cryptographic library.
• Deprecated algorithms (such as MD5, SHA-1 for signatures, or 3DES) still in use.
• No inventory of where cryptography is used.

Enhancements in the Moderate baseline. None; SC-13’s enhancements are all withdrawn.

Federal systems (as of September 2026). Federal systems protecting sensitive information use cryptographic modules validated under FIPS 140. FIPS 140-3 (March 22, 2019) is the current standard, and NIST’s Cryptographic Module Validation Program places new validations on the Active list for five years. Under the program’s FIPS 140-3 transition schedule, FIPS 140-2 modules could be used for new systems until September 21, 2026, and all FIPS 140-2 certificates move to the Historical List on September 22, 2026. The program still supports buying and using Historical List modules for existing systems, and agencies set their own timelines for moving to FIPS 140-3 modules. New systems should use FIPS 140-3 validated modules.

Artifacts

• Encryption and Key Management Standard
• System and Communications Protection Decision Worksheet
• System and Communications Protection Policy