ISC certification Changed CC Questions

Routers control traffic flow between different networks by making routing decisions based on IP addresses. They operate at OSI Layer 3 and determine the optimal path for data packets.

A Virtual Private Network (VPN) creates an encrypted tunnel between a user’s device and a remote network or server. This tunnel protects data confidentiality and integrity by encrypting all traffic passing through it, even when using untrusted networks such as public Wi-Fi.

HTTPS encrypts only web traffic, antivirus detects malware, and IDS monitors for suspicious activity. Only a VPN provides full-tunnel encryption for all network communications. VPNs are commonly implemented using protocols such as IPSec or SSL/TLS and are widely recommended for secure remote access.

Electromagnetic eavesdropping (TEMPEST attacks) exploits signal leakage. EMI shielding blocks emissions, screened rooms prevent signal escape, and white noise generators mask signals. Together, these controls provide comprehensive protection.

A zero-day vulnerability is one that is unknown to the vendor and has no available patch at the time it is exploited. Attackers take advantage of the fact that defenders have “zero days” to fix the issue.

Routine vulnerability scans cannot detect zero-days because scanners rely on known signatures. This is why defense-in-depth, monitoring, and anomaly detection are critical security strategies.