Code:
 ika-engine_0.63.737~0maverick1~ppa1.dsc: Permission denied (publickey).

Unable to connect to SSH host ppa.launchpad.net; EOF during negotiation
E: Error uploading file.
I reinstalled my computer and you know how it is, so not everything has been backed-up. Now I get the feeling I'm missing some sort of public key?

I'll bet I need two keys:
One secret key for the ppa repository.
One public key for uploading to the sftp and

I have my secret key, but I'm missing the public one. Is there any way to get that one back?