A: 

I found someone who ported to iPhone here: http://www.ugosweb.com/cryptopp.aspx#ip

A few things to keep in mind when using it are to set the preprocessor directive as described, but often being able to see the setting to add that directive requires selecting "Active SDK::Use Base SDK" from the top left drop down of xcode, then going into the target settings (get info). Without these steps, the setting in the target settings just isn't there, at least with some xcode versions.

Further, copying the ported proj files works fine but be sure to leave out of your project the ones he leaves out. The files are still around in his crypto folder so do not do a blanket file add to the project and leave it at that.

Joey