Requirement
Employ cryptographic mechanisms to protect the confidentiality of remote access sessions.
Assessment Objectives
- Cryptographic mechanisms to protect the confidentiality of remote access sessions are identified
- Cryptographic mechanisms to protect the confidentiality of remote access sessions are implemented
Potential Assessment Methods and Objects [NIST SP 800-171A]
Examine
- Access control policy
- Procedures addressing remote access to the system
- System security plan
- System design documentation
- System configuration settings and associated documentation
- Cryptographic mechanisms and associated configuration documentation
- System audit logs and records
- Other relevant documents or records
Interview
- System or network administrators
- Personnel with information security responsibilities
- System developers
Test
- Cryptographic mechanisms protecting remote access sessions
Discussion [NIST SP 800-171 REV. 2]
Cryptographic standards include FIPS-validated cryptography and NSA-approved cryptography.
Further Discussion
A remote access session involves logging into the organization's systems such as its internal network or a cloud service provider from a remote location such as home or an alternate work site. Because the use of cryptography in this requirement is to protect the confidentiality of CUI, the cryptography used must meet the criteria specified in requirement SC.L2-3.13.11. Although not explicitly required to meet AC.L2-3.1.13 requirements, this remote access session must be secured using FIPS-validated cryptography to provide confidentiality and prevent anyone from deciphering session information exchanges. This requirement, AC.L2-3.1.13, requires the use of cryptographic mechanisms when enabling remote sessions and complements five other requirements dealing with remote access (AC.L2-3.1.12, AC.L2-3.1.14, AC.L2-3.1.15, IA.L2-3.5.3, and MA.L2-3.7.5).
Examples
Example 1
You are responsible for implementing a remote network access capability for users who access CUI remotely. In order to provide session confidentiality, you decide to implement a VPN mechanism and select a product that has completed FIPS 140 validation [a,b].
Potential Assessment Considerations
- Are cryptographic mechanisms used for remote access sessions (e.g., Transport Layer Security (TLS) and Internet Protocol Security (IPSec) using FIPS-validated encryption algorithms) defined and implemented [a,b]?
References
- NIST SP 800-171 Rev. 2 3.1.13
