How to do SFTP in iPhone?

I have checked the SimpleFTPSample from apple. It works fine. My question is how to do sec开发者_开发技巧ured FTP in iPhone? Is the any samples available?

Start with GCDAsyncSocket to give yourself a sockets layer; grab the Putty source code and get porting.

Putty is very well written but you are going to need to be able to read ANSI C and to be able to convert to objects if you are going to use it.