To create a public key pair, run ssh-keygen-g3 on Client:

Client$ ssh-keygen-g3
Generating 2048-bit dsa key pair
   9 oOo.oOo.oOo
Key generated.
2048-bit dsa, user@Client, Thu Jun 22 2006 12:09:46 +0200
Passphrase : 
Again :
Private key saved to  /home/user/.ssh2/id_dsa_2048_a
Public key saved to   /home/user/.ssh2/id_dsa_2048_a.pub

ssh-keygen-g3 asks for a passphrase for the new key. Enter a sufficiently long (20 characters or so) sequence of any characters (spaces are OK).

The new authentication key pair consists of two separate files. One of the keys is your private key which must never be made available to anyone but yourself. The private key can only be used together with the passphrase.

On Unix, the key pair is by default stored in your $HOME/.ssh2 directory (created by ssh-keygen-g3 if it does not exist previously). On Windows, the key pair is by default stored in your "%USERPROFILE%\Application Data\SSH\UserKeys" directory.

In the example above, the private key file is id_dsa_2048_a. The other file id_dsa_2048_a.pub is your public key, which can be distributed to other computers.

By default, ssh-keygen-g3 creates a DSA key pair. RSA keys can be generated by specifying the -t option with ssh-keygen-g3. Key length can be specified with the -b option. For automated jobs, the key can be generated without a passphrase with the -P option.:

Client$ ssh-keygen-g3 -t rsa -b 1536 -P   

For more information on the ssh-keygen-g3 options, see ssh-keygen-g3(1).