git authentication

[Sreenath Battalahalli]

Hi
I am trying to create a mips build environment on my machine. I am following instructions from
https://github.com/freebsd/freebsd-wifi-build/wiki

The step 
git clone git at github.com:freebsd/freebsd-wifi-build data/freebsd/build
fails with following error:
------
Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.
--------
I have a github account, and I used it instead of "git@" in above command with same result.
I think this is a trivial thing, but can't find an answer.
Do I need to request specific access to freebsd/freebsd-wifi-build  project on Git?

thanks,
Sreenath