A company stores extremely sensitive data on an alt-gapped system. Which of the following can Be Implemented to increase security against a potential insider threat?

An air-gapped system is physically isolated to protect it from external network threats. The primary remaining vulnerability is the insider threat—a malicious or compromised authorized user. Two-person integrity, also known as dual control or the two-person rule, is a procedural control that requires the presence and concurrence of two authorized individuals to perform a sensitive task. This directly mitigates the risk of a single insider acting alone to compromise the system or its data, as it would require collusion, which is significantly more difficult to achieve. This control is specifically designed for high-security environments to protect critical assets from unilateral actions.

B. SSO: Single Sign-On simplifies user access to multiple systems but does not prevent a malicious insider from using their legitimate, authorized credentials to cause harm.
C. SIEM: A Security Information and Event Management system is a detective control that alerts on suspicious activity after it occurs; it does not prevent the initial malicious act.
D. Faraday cage: This protects against electromagnetic eavesdropping (e.g., TEMPEST attacks) from outside the secure area, not against the actions of an authorized insider who is physically present.
E. MFA: Multi-Factor Authentication verifies a single user's identity. It is ineffective against a malicious insider who legitimately possesses all required authentication factors for their own account.

1. National Institute of Standards and Technology (NIST). (2020). Security and Privacy Controls for Information Systems and Organizations (Special Publication 800-53

Revision 5).

Reference: Control AC-3(1) DUAL AUTHORIZATION. The document states

"The information system enforces dual authorization for [Assignment: organization-defined privileged commands and/or other organization-defined actions]." This control is a direct implementation of the two-person integrity principle to prevent unilateral actions.

2. Cappelli

D.

Moore

A.

& Trzeciak

R. (2022). Common Sense Guide to Mitigating Insider Threats (6th ed.). Software Engineering Institute

Carnegie Mellon University.

Reference: Practice 11: "Implement separation of duties and dual control." The guide explains

"Dual control (also known as the two-person rule) requires the approval of at least two authorized individuals to execute a critical task... This practice mitigates the risk of a single insider acting maliciously." (p. 45).

3. Purdue University. (n.d.). Information Security and Privacy Program (S-16).

Reference: Section "Physical and Environmental Security Standard

" Subsection "Facility Access Controls." The standard outlines requirements for securing sensitive areas

stating

"For areas containing Critical IT Resources

implement controls such as... Two-person physical access control." This illustrates the use of this principle in a real-world security policy for critical systems.