Trusted connection between windows and linux

Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted!

I neeed to establish a trusted connection b/w windows and unix.
Are there any links which guides me to do that.

I know that we should have a public key. Did this b/w unix 2 unix.

Did a ftp to windows client and transferrred my file which contains public key but unable to find that file. ?

Are there any threads to achieve this ?

Please fill out the complete template (school/university, course number, professor, ...).