Have you lost your public SSH key? If the answer is yes, this article is for you because I explain how to regenerate your public key from an existing private key.
This is really easy to do, so I'll keep this short. Here is the terminal command:
ssh-keygen -t dsa -y > ~/.ssh/id_dsa.pub
The public key will appear in your .ssh folder. Remember: it doesn't matter who has your public key, but never give out your private key.