Generate a secure SSH key

Fri, 10 Aug 2018 14:42:19 +0000

In Fedora, CentOS and probably many other Linux distros ssh-keygen; still defaults to RSA 2048.
People have not yet realized that the newer, and also faster, elliptic curve cryptography is available; even between my peers I still see that many of them are using old and insecure RSA based keys. Since SSH clients support multiple keys transitioning to newer keys can be painless:

create a new elliptic curve key;
do not delete the old RSA key;
once you login into a server swap the old key with the new one.
Generating a new secure SSH key is pretty simple, just open a terminal and run:

ssh-keygen -o -a 256 -t ed25519

Cryptography on nagg.eu

Generate a secure SSH key