ssh keys for server login

factor

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All:
Just wondering if others are still using RSA keys or have you switched to something newer like ecdsa (elliptical curve) for server key login?

Noted: https://www.ssh.com/ssh/keygen/

Choosing an Algorithm and Key Size​

SSH supports several public key algorithms for authentication keys. These include:

  • rsa - an old algorithm based on the difficulty of factoring large numbers. A key size of at least 2048 bits is recommended for RSA; 4096 bits is better. RSA is getting old and significant advances are being made in factoring. Choosing a different algorithm may be advisable. It is quite possible the RSA algorithm will become practically breakable in the foreseeable future. All SSH clients support this algorithm.
  • dsa - an old US government Digital Signature Algorithm. It is based on the difficulty of computing discrete logarithms. A key size of 1024 would normally be used with it. DSA in its original form is no longer recommended.
  • ecdsa - a new Digital Signature Algorithm standardized by the US government, using elliptic curves. This is probably a good algorithm for current applications. Only three key sizes are supported: 256, 384, and 521 (sic!) bits. We would recommend always using it with 521 bits, since the keys are still small and probably more secure than the smaller keys (even though they should be safe as well). Most SSH clients now support this algorithm.
  • ed25519 - this is a new algorithm added in OpenSSH. Support for it in clients is not yet universal. Thus its use in general purpose applications may not yet be advisable.
I ask because the old doc still shows rsa
So does the new doc

So i wonder if there is some reason not to use ecdsa?
 
I'm still using RSA keys with a password. I've seen others, but ed25519 is as you wrote not universal yet. DSA is not safe enough anymore and ecdsa... what does "sic!" means in this context? Isn't 521 too small.

So imho at this moment, rsa is still the preferred way to go.
 
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