Which of the following is NOT a common social engineering technique?

The correct answer is encryption, as it is a technical measure used to secure data by converting it into a code to prevent unauthorized access. Encryption protects information while it is stored or transmitted, ensuring confidentiality and integrity. It is not a social engineering technique, which typically involves manipulating individuals into providing sensitive information or access to secure locations through psychological tactics.

In contrast, phishing, pretexting, and tailgating are all recognized social engineering techniques. Phishing involves sending fraudulent communications that appear to come from reputable sources to trick individuals into revealing personal information. Pretexting refers to creating a fabricated scenario to obtain confidential information from the target. Tailgating is a physical social engineering attack where an unauthorized person follows an authorized individual into a secure area. These methods rely on exploiting human trust rather than technical vulnerabilities.