Lecture Notes: Dictionary Attacks What is a Dictionary Attack? A dictionary attack is a type of password cracking technique that involves trying common words, phrases, or patterns to guess a user's password. Attackers use dictionaries or lists of common passwords to systematically try different combinations until they find a match. How Dictionary Attacks Work 1. Obtain a Dictionary: Attackers use dictionaries or lists of common words, phrases, or personal information to create a list of potential passwords. 2. Hashing: The attacker hashes each potential password using the same hashing algorithm as the target system. 3. Comparison: The attacker compares the hashed passwords from the dictionary with the hashed passwords stored on the target system. 4. Match: If a match is found, the attacker has successfully cracked the password. Types of Dictionary Attacks ● Rainbow Table Attacks: Pre-computed tables of hashed passwords are used to quickly crack passwords. ● Hybrid Attacks: Combine dictionary attacks with brute-force attacks to increase the chances of success. ● Rule-Based Attacks: Use rules or patterns to generate potential passwords, such as combining common words and numbers. Mitigating Dictionary Attacks ● Strong Passwords: Use strong, unique passwords that are difficult to guess. ● Password Complexity Requirements: Enforce password policies that require a combination of uppercase and lowercase letters, numbers, and special characters. ● Password Managers: Use password managers to securely store and manage complex passwords. ● Two-Factor Authentication (2FA): Require a second factor of authentication, such as a code sent to a mobile device, in addition to a password. ● Regular Password Changes: Encourage users to change their passwords regularly. ● Password Aging: Set password aging policies to require users to change their passwords after a certain period of time. Conclusion Dictionary attacks are a common password cracking technique that can be used to gain unauthorized access to systems. By implementing strong password policies and using effective security measures, organizations can reduce the risk of successful dictionary attacks.