Simple definition
A file that lists public keys that are allowed to connect to an account via SSH.
Technical definition
The file ~/.ssh/authorized_keys is read by OpenSSH to validate public key authentication.
What is it used for ?
Control which keys can log in SSH.
Practical example
The public key of a technician can be added in authorized_keys the administration account.
Common issues
- Bad permissions
- Old key never removed
- Key added to the wrong account
Related terms
Key takeaway: Exact behavior and commands may vary depending on versions, products and architectures.