Create a Strong SSH Key in Linux

SSH is a client/server protocol used for remote logins. Using cryptography for authentication, ssh provides an encrypted method to access your server. The two of the most popular methods of authentication are passwords based and public-key-based authentication. Public key authentication uses the cryptography system of key pairs that allows you to authenticate to your server without sending your password over the network.

This article will walk you through the steps of creating a public and private key pair on your local machine using the ssh-keygen tool.

Creating SSH Keys

Creating ssh key pairs using different encryption algorithms.

• RSA – This algorithm uses the difficulty of factoring large numbers. A minimum of 2048 bits is recommended, but 4096 is considered significantly better.

ssh-keygen -t rsa -b 4096

• ECDSA – Stands for Elliptic Curve Digital Signature Algorithm, which uses elliptic-curve cryptography

ssh-keygen -t ecdsa -b 521

• ed25519 – Fairly new algorithm which is intended to provide attack resistance comparable to quality 128-bit symmetric ciphers.

ssh-keygen -t ed25519

Once your key is created, you can upload your Public Key to our Cloud Control panel as detailed in the SSH-Key Management article below.