How to fix the electromagnetic information leakage vulnerability?

To fix the electromagnetic information leakage vulnerability, you need to understand that this type of vulnerability occurs when sensitive data is unintentionally emitted through electromagnetic radiation (EMR) from electronic devices—such as monitors, keyboards, or processors—and can be captured and reconstructed by attackers using specialized equipment (a type of side-channel attack known as Van Eck phreaking or TEMPEST).

Explanation:

Electromagnetic (EM) leakage happens because all electrical circuits emit some level of electromagnetic radiation during operation. If not properly shielded or suppressed, these signals can carry enough information about the data being processed—like screen content or keystrokes—for an attacker to decode it remotely.

This type of vulnerability is particularly critical in environments requiring high security, such as military, government, or financial institutions.

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Fixing Methods:

1. Proper Shielding:

   • Use TEMPEST-certified or Faraday cage-like enclosures for sensitive equipment.
   • Ensure that computer monitors, CPUs, and other hardware are housed within materials that block or significantly reduce electromagnetic emissions.
   • Example: A TEMPEST-shielded room prevents external monitoring of internal electromagnetic signals.

2. Signal Suppression:

   • Implement EMI (Electromagnetic Interference) filters on power and signal lines.
   • Use spread spectrum clocking techniques to make intentional electromagnetic emissions less predictable and harder to decode.
   • Reduce unnecessary high-frequency clock signals that may emit stronger EM fields.

3. Physical Security:

   • Place sensitive systems in secure, controlled-access areas where electromagnetic eavesdropping is physically difficult.
   • Maintain minimum distances between sensitive equipment and potential eavesdropping points.

4. Monitor and Audit Emissions:

   • Conduct regular electromagnetic emission testing to detect unexpected signal leakage.
   • Use spectrum analyzers to identify abnormal frequency patterns that might indicate data leakage.

5. Software-Level Mitigations (Limited Effectiveness):

   • While software alone cannot fully prevent EM leakage, reducing the amount of sensitive data displayed or processed at any given time can help minimize risk.
   • For example, avoid displaying full sensitive documents on-screen unnecessarily.

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Example Scenario:

Imagine a banking system where a user enters their PIN on a keyboard. If the keyboard or connected system emits detectable electromagnetic patterns corresponding to each keypress, an attacker with the right equipment sitting nearby could reconstruct the entered PIN. To mitigate this:

• The keyboard and system could be enclosed in a shielded casing.
• Signal filtering could suppress unnecessary emissions.
• The system could be located in a room designed to contain electromagnetic signals.

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Recommended Tencent Cloud Services (if applicable):

If you're deploying secure computing environments in the cloud, Tencent Cloud's Virtual Private Cloud (VPC) and dedicated secure hosts can help isolate sensitive workloads. Additionally, Tencent Cloud Security Center provides continuous monitoring and compliance checks that can include aspects of physical and environmental security guidance. For highly sensitive applications, consider using Tencent Cloud's BM (Black Metal) servers, which offer dedicated physical resources with enhanced control over the hosting environment, aiding in implementing proper shielding and access controls.