What is the recommended bit length for password protection against brute force attacks?

The recommended bit length for password protection against brute force attacks centers around the trade-off between security and usability. A password with a length of 128 bits provides a substantial level of security. This is because each additional bit in a password doubles the number of possible combinations, making it exponentially harder for an attacker to successfully guess the password through brute force methods.

With a 128-bit password, the total number of combinations is 2^128, which is an astronomically large number, approximately 3.4 x 10^38. This sheer scale means that even the most powerful computers would take an impractically long time to attempt every possible combination. Consequently, this level of complexity is considered secure against brute force attacks for the foreseeable future, providing a robust level of protection for sensitive information.

While higher bit lengths can enhance security even further, such as with 256 or 512 bits, these are often unnecessary for most applications and could lead to performance issues or user fatigue regarding password management, as they can be harder to create and remember. Therefore, 128 bits strikes a balance between strong security and practical usability.