2.2.1 Shadow Passwords and Hashing Algorithms

By default, an Oracle Linux system is configured to use password hashes that are stored in the /etc/shadow file rather than in the world-readable /etc/passwd file. If shadow passwords were not used, an attacker is much more likely to be able to discover a password by applying cracking software to the hashes. Similarly, using a password-hashing algorithm that is weaker than SHA-512 would make it much easier to find likely candidates that match a hash value.