Why should I use SSH keys instead of passwords?

SSH keys are significantly more secure than passwords. They are nearly impossible to brute-force, they are not transmitted over the network (preventing sniffing), and they allow for automated, passwordless logins, which is essential for scripting and deployment pipelines.

What is the difference between RSA, ECDSA, and Ed25519?

These are different cryptographic algorithms. RSA is the oldest and most widely supported. ECDSA is newer and provides similar security to RSA with smaller key sizes. Ed25519 is the most modern, offering excellent security and performance. For new systems, Ed25519 is often recommended, but RSA (2048-bit or higher) remains a very safe and compatible choice.

How do I use the generated keys?

After generating, you need to copy the public key (the one starting with `ssh-rsa`, `ecdsa-...`, or `ssh-ed25519`) and paste it into the `~/.ssh/authorized_keys` file on the server you want to connect to. The private key should be saved on your local machine (usually at `~/.ssh/id_rsa` or a similar name) with strict file permissions (readable only by you).

SSH Key Generator

What is an SSH Key?

An SSH key pair provides a secure way of logging into a remote server or system without needing a password. It utilizes public-key cryptography to authenticate a user. The pair consists of a private key, which you keep secret on your local machine, and a public key, which you place on the server.

How It Works

You attempt to connect to a server.
The server has your public key and sends a challenge, encrypted with that key.
Only your corresponding private key can decrypt this challenge.
Your local SSH client decrypts the challenge, solves it, and sends the correct response back to the server.
The server verifies your response and grants you access, all without a password ever being transmitted over the network.

Frequently Asked Questions (FAQs)

What is an SSH Key?

How It Works

You attempt to connect to a server.
The server has your public key and sends a challenge, encrypted with that key.
Only your corresponding private key can decrypt this challenge.
Your local SSH client decrypts the challenge, solves it, and sends the correct response back to the server.
The server verifies your response and grants you access, all without a password ever being transmitted over the network.

SSH Key Generator