chmod 600 — what rw------- means
600
rw-------
The owner can read and write; group and others have no access whatsoever.
Permission breakdown
When to use 600
Sensitive files only the owner should see — SSH private keys, password files, .env secrets, API tokens. Many tools (like SSH) refuse to use a key file unless it is 600.
Set it with chmod
Apply this permission to a file:
chmod 600 filenameOr apply it recursively to a directory and everything inside it:
chmod -R 600 directory/Other common permissions
Or build any permission with the interactive chmod calculator.