What can help mitigate brute-force attacks effectively?

Mitigating brute-force attacks requires strategies that make it significantly more difficult for attackers to gain unauthorized access through guessing or systematically trying various passwords. Implementing two-factor authentication is particularly effective because it adds an additional layer of security beyond just the password. Even if an attacker successfully guesses or cracks a password, they would still need the second factor, often something physical like a smartphone app or hardware token, to gain access.

Tightening password complexity requirements helps ensure that passwords are more complex and harder to guess, which does indeed make brute-force attacks less effective. However, it does not directly prevent them; it merely increases the difficulty level for the attacker.

Increasing session expiration and conducting regular security assessments are also beneficial practices but do not specifically target or significantly mitigate the risk of brute-force attacks. Session expiration helps manage user sessions but is more about session management than password security. Regular security assessments help identify vulnerabilities but do not actively prevent brute-force attempts at the point of access. Thus, while tightening password complexity is important, it alone is not the most effective strategy compared to implementing two-factor authentication.