Which Language to choose for business application?
I am curious which programming language one would choose to create two kinds of applications:

 - Encryption of a Folder/HardDrive 
 - Data Leakage Prevention Software   
   (Persistent Control of Documents + Control of Network Activity)

The main goal is to make it fast, even on older hardware and to protect against reverse engineering. Also to have a rapid development. The platform it will be used on should be Windows.

Any suggestions? I thought about C as a quite system-close language. Programming skills do not matter at this moment.
Which Language to choose for business application?
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I am curious which programming language one would choose to create two kinds of applications:

 - Encryption of a Folder/HardDrive 
 - Data Leakage Prevention Software   
   (Persistent Control of Documents + Control of Network Activity)

The main goal is to make it fast, even on older hardware and to protect against reverse engineering. Also to have a rapid development. The platform it will be used on should be Windows.

Any suggestions? I thought about C as a quite system-close language. Programming skills do not matter at this moment.