What Are SSH Keys?

SSH keys are cryptographic key pairs used to authenticate users and systems when accessing remote machines through Secure Shell (SSH). They provide a more secure alternative to password-based authentication.

SSH uses a client–server model. The client initiates a connection, and the server establishes an encrypted communication channel. Authentication then occurs using an SSH key pair instead of a password.

The private key remains securely stored on the client system, while the public key is placed on the server. During authentication, the server verifies that the client possesses the correct private key without the key ever being transmitted.

SSH keys are commonly used for administrative access, automated system communication, and DevOps workflows. While they enhance security, unmanaged SSH keys can accumulate quickly, making governance and visibility essential.