Ed25519 Ssh Key

Posted : admin On 1/2/2022

Could not load host key: /etc/ssh/sshhosted25519key - ssh-ed25519-freebsd.md. Ed25519 key pairs can be generated with: $ ssh-keygen -t ed25519 There is no need to set the key size, as all Ed25519 keys are 256 bits. Keep in mind that older SSH clients and servers may not support these keys.

The Ed25519 was introduced on OpenSSH version 6.5. It’s the EdDSA implementation using the Twisted Edwards curve. It offers a better security with faster performance compared to DSA or ECDSA. Some benefits are that its faster, and compact – it only contains 68 characters, compared to RSA 3072 that has 544 characters. Generating the key is fast! It’s also fast to perform batch signature verification with Ed25519.

To test, you will need a client and test server. The client server is where we generate the keys. When we generate keys, there will be a private key and a public key. Then we copy the public key to the test server. When we ssh to the test server, the private key we have on the client server matches the public key that we copied to the test server. To generate a new pair of SSH keys that uses Ed25519 algorithm on the client server, run:

Ed25519 Ssh Keygen

Specifies filename of the keyfile, used for specifying other than default name
number of primality test while screening DH-GEX candidates
type of key (RSA, ED25519, DSA, etc)
Comment (not used in algorithm, only used in public key)
openSSH key format instead of older PEM (needs OpenSSH 6.5+)

On the server, check for the .ssh direstory. If it is not there , you will need to create it.
On Server, make directory and set permissions


On Client, Copy Public SSH Key to Server
Using the command “ssh-copy-id” is the preferred way. You will need to have ssh access to the server to copy the key.
Here is the command:

If you want to just login to the server with the hostname vs the full domain like:

Ed25519 Ssh Key

Ed25519 Ssh Key


ssh “server1” vs “ssh -p ’22’ ‘[email protected]'”, then add a hostname entry to the client with the following:


Github Ed25519 Ssh Key


Now try the short ssh: