Upgrade your old RSA SSH key to Ed25519
The RSA algorithm has some problems and you should update to Ed25519
If you work regularly with remote machines or use online services like Gitlab, you are probably using an SSH key. And if you have not updated it recently, chances are you are using an RSA key, or, god forbid, an ECDSA or DSA key. Well, bad news: in order to be on the safe side, you should probably upgrade. A presentation at BlackHat 2013 reported significant advances in solving the problems on which DSA and some other key types are based. The presentation suggested that keys based on elliptic curve cryptography (ECC) should be used instead: ECDSA or Ed25519. Additionally, ECDSA and DSA have nasty additional issues, so you should probably just stick to Ed25519. Here’s how to upgrade.