CAS-005 Questions Bank

Homomorphic encryption allows computations to be performed on encrypted data without decrypting it, providing strong privacy guarantees. However, the adoption of homomorphic encryption is challenging due to several factors:

A. Incomplete mathematical primitives: This is not the primary barrier as the theoretical foundations of homomorphic encryption are well-developed.

B. No use cases to drive adoption: There are several compelling use cases for homomorphic encryption, especially in privacy-sensitive fields like healthcare and finance.

C. Quantum computers not yet capable: Quantum computing is not directly related to the challenges of adopting homomorphic encryption.

D. Insufficient coprocessor support: The computational overhead of homomorphic encryption is significant, requiring substantial processing power. Current general-purpose processors are not optimized for the intensive computations required by homomorphic encryption, limiting its practical deployment. Specialized hardware or coprocessors designed to handle these computations more efficiently are not yet widely available.

References:

CompTIA Security+ Study Guide

"Homomorphic Encryption: Applications and Challenges" by Rivest et al.

NIST, "Report on Post-Quantum Cryptography"

The best action to address the requirement of accessing the historian server within a SCADA system is to isolate the historian server for connections only from the SCADA environment. Here’s why:

Security and Isolation: Isolating the historian server ensures that only authorized devices within the SCADA environment can connect to it. This minimizes the attack surface and protects sensitive data from unauthorized access.

Access Control: By restricting access to the historian server to only SCADA devices, the organization can better control and monitor interactions, ensuring that only legitimate queries and data retrievals occur.

Best Practices for Critical Infrastructure: Following the principle of least privilege, isolating critical components like the historian server is a standard practice in securing SCADA systems, reducing the risk of cyberattacks.

References:

CompTIA Security+ SY0-601 Study Guide by Mike Chapple and David Seidl

NIST Special Publication 800-82: Guide to Industrial Control Systems (ICS) Security

ISA/IEC 62443 Standards: Security for Industrial Automation and Control Systems

Based on the provided logs, the user has accessed various applications from different geographic locations within a very short timeframe. This pattern is indicative of the "impossible travel" security rule, a common feature in Single Sign-On (SSO) systems designed to detect and prevent fraudulent access attempts.

Analysis of Logs:

At 8:47 p.m., the user accessed a VPN from Toronto.

At 8:48 p.m., the user accessed email from Los Angeles.

At 8:48 p.m., the user accessed the human resources system from Los Angeles.

At 8:49 p.m., the user accessed email again from Los Angeles.

At 8:52 p.m., the user attempted to access the human resources system from Toronto, which was denied.

These rapid changes in location are physically impossible and typically trigger security measures to prevent unauthorized access. The SSO system detected these inconsistencies and likely flagged the activity as suspicious, resulting in access denial.

References:

CompTIA SecurityX Study Guide

NIST Special Publication 800-63B, "Digital Identity Guidelines"

"Impossible Travel Detection," Microsoft Documentation

A proxy-based Cloud Access Security Broker (CASB) is chosen primarily for its ability to block unapproved applications and services. Here’s why:

Application and Service Control: Proxy-based CASBs can monitor and control the use of applications and services by inspecting traffic as it passes through the proxy. This allows the organization to enforce policies that block unapproved applications and services, ensuring compliance with security policies.

Visibility and Monitoring: By routing traffic through the proxy, the CASB can provide detailed visibility into user activities and data flows, enabling better monitoring and threat detection.

Real-Time Protection: Proxy-based CASBs can provide real-time protection against threats by analyzing and controlling traffic before it reaches the end user, thus preventing the use of risky applications and services.

References:

CompTIA Security+ SY0-601 Study Guide by Mike Chapple and David Seidl

NIST Special Publication 800-125: Guide to Security for Full Virtualization Technologies

Gartner CASB Market Guide