312-50v13 Exam Dumps : Certified Ethical Hacker Exam (CEHv13)

A low-and-slow scanning technique spreads probe attempts over long intervals, reducing the chance of triggering IDS signatures that rely on detecting rapid or high-volume scans. CEH highlights timing-based evasion as an effective method for reconnaissance against networks with strict perimeter controls.

The correct answer is D. Brute force. A brute-force attack is a password-cracking method that systematically attempts every possible combination of characters until the correct password is discovered. Because it does not rely on precompiled wordlists, common passwords, or previously generated hash databases, it is considered the most exhaustive and time-consuming password-cracking technique.

In CEH password-attacking concepts, a dictionary attack is generally faster because it uses a predefined list of commonly used passwords and words. Rainbow tables are even faster in many situations because they rely on precomputed hash values that can be matched against captured password hashes. Shoulder surfing is not a technical password-cracking method; it involves directly observing a user entering credentials.

The effectiveness and duration of a brute-force attack depend on password complexity, length, character set, account lockout policies, and available computing power. Strong passwords containing uppercase letters, lowercase letters, numbers, and special characters significantly increase the number of possible combinations, making brute-force attacks far more difficult and time-consuming.

CEH Exam Tip:

Dictionary Attack = Faster, wordlist-based.

Rainbow Tables = Precomputed hash lookup.

Brute Force = Tries every possibility; most time and effort required.

Shoulder Surfing = Social engineering observation technique.

Therefore, Brute Force is the correct answer.

The correct answer is C. S/MIME.

S/MIME, or Secure/Multipurpose Internet Mail Extensions, is the email security standard used to provide encryption and digital signing for MIME-based email messages. The CEH cryptography reference describes S/MIME as a standard for public-key encryption and signing of MIME data . It is also defined as a standard for encrypting and authenticating MIME data, primarily used for Internet email .

This directly matches the scenario because the organization requires:

Confidentiality through email encryption.

Authentication through digital signatures.

PKI-based trust using certificates.

Compatibility with Microsoft Outlook environments.

Option A. FlowCrypt is incorrect because it is an email encryption tool/service, mainly associated with OpenPGP-based email encryption, not the standard being asked for.

Option B. RMail is incorrect because it is a secure email service/platform, not the core standardized PKI-based email encryption framework.

Option D. OpenPGP is incorrect because OpenPGP supports encryption and signatures, but it is not the best match where the requirement specifically emphasizes certificate authority-based PKI trust and Outlook-style enterprise certificate validation.

Therefore, the best answer is C. S/MIME.