Don't link back to them and you will be safe however, it would be better to elaborate your question a little to make more sense
Please explain l'll bit, to solve your query. If you are asking to make secure your site from hackers and phishers than you need to go for SSL certificates, which encrypts your data and make it more secure.
If you are running your own server, install a firewall, make sure no files are writable, and use SSL.