What characteristic of cryptographic hashing functions makes them secure for passwords?

The characteristic that makes cryptographic hashing functions secure for passwords is that they are one-way functions. This means that once data has been transformed into a hash value, it is virtually impossible to revert that hash back to the original data. This property is crucial for password storage because it adds a layer of security; even if an attacker gains access to the hashed passwords, they cannot easily retrieve the original plaintext passwords.

The one-way nature of hashing protects user credentials by ensuring that the transformation preserves the uniqueness of the input while making it computationally infeasible to derive the input from its hash. This characteristic is essential for safeguarding against various types of attacks, such as brute-force attacks, where an attacker tries to guess the password combinations.

Other aspects of cryptographic hashing, such as generating consistent output for the same input, while important for validating passwords, do not directly contribute to the security of the hashing method itself. Furthermore, the ability to reverse a hash or decrypt it is contrary to the core purpose of a cryptographic hash function. Hence, the one-way function property is what fundamentally underpins the security feature of cryptographic hashing in the context of password protection.