3 Last Password Change Date of last change, counted in days since Jan 1, 1970. These files, typically found at /etc/shadow on Unix-like systems, store the most sensitive authentication data.
Shadow File Format Algorithm Identifier
Historically, password hashes were world-readable in the main password file, allowing any user to run brute-force attacks. File permissions are usually set to -rw-r----- , owned by root with group ownership of shadow or shadow-t.
Regular audits of these permissions are necessary to prevent privilege escalation. 7 Password Inactivity Period Number of days after expiration before the account is disabled.
Shadow File Format Algorithm Identifier Explained
4 Minimum Password Age Number of days a user must wait before changing the password again. Instead, formats like $6$ (SHA-512), $5$ (SHA-256), and $y$ (Yescrypt) are standard.
More About Shadow file format
Looking at Shadow file format from another angle can help expand the discussion and give readers a second clear paragraph under the same section.
More perspective on Shadow file format can make the topic easier to follow by connecting earlier points with a few simple takeaways.
