How to prevent an applications DLL to be decompiled?

Question

As I know there are some applications that decompile DLLs to get source codes from application files.

Not only I don't want others to have the sources but also I don't want others to use them, I mean the DLL files. so how should i lock the DLLs and how safe they are ?

possible duplicate of [Protect .NET code from reverse engineering?](http://stackoverflow.com/questions/506282/protect-net-code-from-reverse-engineering) — Carbine, Oct 13 '14 at 12:07
Short answer is you _can't_. You can make some obfuscation on your DLL to make the decompiled source harder to read/compile. — kennyzx, Oct 13 '14 at 12:09
Host it on a server and have client connect through a remote desktop client. — Emond, Oct 13 '14 at 12:11
Erno its a good idea , may be i use SMS validation using Online SMS panels — Majid khalili, Oct 13 '14 at 12:18

score 2 · Accepted Answer · edited May 23 '17 at 11:45

Before I get into anything else, I will state that it is impossible to protect your application entirely.

That being said, you can still make things more difficult. There are many obfuscators out there that will help you make it more difficult for someone to decompile your application and understand it.

That's truly the best you can hope for.

Personally, I really wouldn't bother going too deep, if at all. You'll find that you are either spending too much money or time (or both) trying to protect your application from no-gooders. These are the same people who, no matter what barriers you throw up at them, will continue to try and given the nature of managed languages, they will most likely succeed. In fact, most obfuscators can be deobfuscated with simple tools... In the meantime, you've let other important features and bug fixes slip by because you spent more time and effort on security measures.

so i really shouldn't bother spending time on that other than usual ways ?!! — Majid khalili, Oct 13 '14 at 12:35
It's mostly opinion based, but pretty much I think exactly that. — myermian, Oct 13 '14 at 12:44

score 1 · Answer 2 · answered Nov 13 '14 at 11:14

1

Obfuscation is one way to protect your code. Again, the solution is relative as per your needs. If you have a super secretive program, then you would want to explore more expensive and in-dept strategies.

However, if you are developing a business application or such thing which would not be worth a lot of any hacker's time to reverse engineer, minimal to normal obfuscation strategies are good enough. As the main answer suggests, look at those links.

Recently, I came upon ConfuseEx, a free open-source obfuscator that does the job for WPF apps and more. It seems to be very powerful, effective and customizable.

ConfuseEx on Github

answered Nov 13 '14 at 11:14

dotnetzen

166
1
9

and do u know anything about the confuseEx providers ? – Majid khalili Nov 19 '14 at 14:17
Hi Majid, no I don't personally know. It is an open source project on Github, and was initially on codeplex. Check the link I provided for more info. – dotnetzen Nov 19 '14 at 23:37
i just wanted to know that if they are pro or not , but thanks , ill check and let u know about it too . – Majid khalili Nov 20 '14 at 06:59

score 0 · Answer 3 · answered Sep 20 '15 at 07:16

For DLLs there is almost nothing we can do , confusing the files is the best way , but public member will remain in the way they were before , but if you pack them in your exe file , and confuse them , no one can use them easily . I used ConfuserEX and it was very easy to use and effective .

How to prevent an applications DLL to be decompiled?

3 Answers3

Linked