Is it safe to use a hash as a password?

Passwords, as the key to accessing sensitive information, require robust security measures to safeguard them. Hashing and encryption are two common techniques employed to protect passwords, yet their usage differs significantly in specific contexts.

When it comes to protecting passwords, hashing emerges as the preferred method. Hashing involves converting the password into a fixed-length value, known as a hash, which cannot be reversed to obtain the original password. This one-way function ensures that even if the hash is compromised, the attacker cannot retrieve the original password.

In contrast, encryption involves transforming the plaintext password into ciphertext that can be decrypted back to the original plaintext. While encryption offers robust security for data transmission, it is not suitable for password storage due to the potential for decryption, posing a risk if the encryption key is compromised.

Consequently, hashing is the ideal choice for password validation. During user authentication, the system hashes the entered password and compares it with the stored hash value. If they match, the user is granted access, ensuring that the system never needs to store or transmit the actual password.

This approach enhances security as even if an attacker gains access to the hashed passwords, they cannot determine the original passwords without engaging in computationally intensive brute-force attacks, which are often impractical due to the high time and resource costs.