Question

About to complete a wp7 application, which uses bing map services for locations etc. I need to know if obfuscation will hamper its performance.

There are some tools available like Dotfuscator etc, but concerned about the performance of the app. Please give your suggestions

Answer 1

I do not have much experience with obfuscation, however what I do know is there are two methods.

1. Simply renaming of variables and functions to make it difficult to read the logic when decompiled using Reflector; and
2. The other where program flow is be rearranged.

With name obfuscation the IL code and runtime performance is the same. There is apparently a difference in performance with the second method, however the only benchmarks/articles I can find are for Java.

You are deploying to a secure device and file system so there is no need to obfuscate a WP7 application. As Chris pointed out, you can actually get the application package file by intercepting the HTTP request from the marketplace and extracting the GUID as detailed in a blog post by Marius Gheorghe. As Marius explains this is because the XML stream is not encrypted and that the assembly package can be retrieved using a simple request. I would expect Microsoft to patch/fix this soon (and I will mention it to our Microsoft account manager).

As for WP7 obfuscation there is a detailed blog post here that should help.

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If you want to secure your application, I would spent the time encrypting your persisted data (i.e. save files) so that your users data is secure. That is what did for the WP7 Full House Poker game.