The act of obscuring something to make it more difficult to understand is called obfuscation. Lawyers are sometimes accused of obfuscation, since legal contracts can be so difficult to understand.
The word obfuscation is from the verb obfuscate, which itself comes from the Latin word obfuscare, meaning "to darken." The confusion that results when something is muddled or obfuscated is also called obfuscation. If you intentionally make something more complex or more difficult to see or understand, then you are guilty of obfuscation.