chmod 700 Explained — Owner-Only Full Access

What Does chmod 700 Mean?

Permission 700 grants the owner full access while completely blocking everyone else:

Role	Octal	Symbolic	Permissions
Owner	7	rwx	Read + Write + Execute
Group	0	---	No access
Others	0	---	No access

Where to Use 700

# SSH directory (required by SSH)
chmod 700 ~/.ssh

# Private home directory
chmod 700 ~

# Application data directories
chmod 700 /opt/myapp/data

# Backup directories
chmod 700 /var/backups/private

700 for Directories

For directories, 700 means only the owner can:

• Read (r): List the directory contents with ls
• Write (w): Create, rename, or delete files within
• Execute (x): Enter the directory with cd and access files inside

Other users cannot even see what files exist in the directory.

700 vs 600

• 700 is for directories and executable files (the owner needs execute)
• 600 is for regular files (read+write without execute)

Using 600 on a directory would prevent even the owner from entering it, since directories require execute permission for traversal.

SSH Directory Requirements

SSH enforces strict permission checks:

• ~/.ssh must be 700
• Files inside must be 600 (private keys, authorized_keys)
• If permissions are too open, SSH silently ignores the configuration