Question

I have an iPhone app that communicates with a server (both of which I own and wrote the code for). I need to way to determine if a request on my server came from an iPhone (or any mobile device running the app I wrote for that matter). Basically, I only want to allow apps that I wrote to communicate with the server and need a way to verify that. Since I’m writing the apps, I can modify the headers and what not any way I need to.

I read up a little on Public Key Encryption, but I don’t think it’d work. If I sent some sort of secret hashed word in my headers to verify it, couldn’t some outside party simply get those headers and use the same ones in their request?

Answer 1

You can use a checksum. Let’s say that you have something like:
date
subject

and calculate the checksum by using, let’s say MD5 of (date + “string” + subject),
and you calculate the MD5 in the very same way on the server. If they match, they are from the mobile client.

This will work until someone figures out your algorithm.