How Can I Protect My C# Code From Being Decompiled?

Question

Possible Duplicate:
.Net Obfuscation
Alternative for Obfuscation in the .NET world

Just a few minutes ago, I read that there are a number of tools, many free, that allow you to convert a C# .exe back to a VB solution. This means that my proprietary code can be viewed, edited, and recompiled/redistributed. Is there a way to prevent this?

score 2 · Accepted Answer · edited Mar 12 '12 at 16:57

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In short you need to use Obfuscation. To name a few.

Dotfuscator
Obfuscator
Skater (Freeware)
DeployLX CodeVeil
Plus Visual Studio comes with a light version of Dotfuscator.

You can read this MSDN article that has advice on how to obfuscate your code.

edited Mar 12 '12 at 16:57

Paul Alexander

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answered Sep 06 '11 at 03:52

Mark Hall

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Thanks for the answer. I will look into both. (Edit: I will look into all 4.) – Matt Sep 06 '11 at 03:59

score 1 · Answer 2 · answered Sep 06 '11 at 03:51

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You can use an Obfuscator.. Salamander is one such tool for .NET...

Confuser is another free obfuscator for .NET. It is developed in C# and using Mono

answered Sep 06 '11 at 03:51

Prabath Siriwardena

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score 0 · Answer 3 · answered Sep 06 '11 at 03:50

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You can use mono to compile it to a native binary, just google it up.

answered Sep 06 '11 at 03:50

Daniel

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score 0 · Answer 4 · answered Sep 06 '11 at 03:55

You could also code the sensitive functions/components into native C++, wrap it in C++/CLI and use with .NET in addition to obfuscating your .NET assemblies.

Even with obfuscation the JIT compiler will need to see the IL code eventually, you are just making it more difficult to decompile.

score 0 · Answer 5 · edited May 23 '17 at 12:29

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An obfuscator is a good bet, as it increases a person's effort to view, edit, redistribute, etc. the code.

While these don't protect your code physically they could prevent the behavior of decompiling your code: legal mechanisms such as patents, copyrights, and licenses.

Decompiling or reverse engineering is a battle of economic efforts. Is it worth it for you to obfuscate your code (potentially running afoul of reflection "gotchas") vs. is it worth it for someone to reverse engineer (with little context) instead of emulating or rewriting?

A comment on this answer, https://stackoverflow.com/a/1988467/64348, with which several agree, indicates that obfuscation does not prevent getting back to the original (or some close enough version of the original) code. Obfuscation is just a stand-in to a reversible translation with no real key needed except some useful context.

edited May 23 '17 at 12:29

Community

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answered Sep 06 '11 at 03:55

Kit

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Don't you mean it *increases* the effort required? – Ben Voigt Sep 06 '11 at 03:56
@Ben, oops yes. Maximizes the other party's effort, minimizing their gain by decompiling. – Kit Sep 06 '11 at 04:02
@Matt - np. I used to worry about this a little too much, but the legal folks are way more versed than us techies! – Kit Sep 06 '11 at 04:06

How Can I Protect My C# Code From Being Decompiled?

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