How do you 'design' a byte code?

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interpreters

I've been created an interpreter for an scripting engine for my games, and I've created it. But the problem is that I don't want to others to be able to see the code (script), for that, I need to create a compiler that compiles the script to a byte code. But how do you 'design' a byte code? How I do it is try to make it as hard as possible for a human to understand it, while making it easier to interpret it for the interpreter.

What I have tried:

I've designed a byte code that is harder for the user to understand, and is very fast for the interpreter to execute. But the problem is that although a human cannot understand the byte code, a decompiler can be made for the current byte code I have, with a bit of difficult. This is how I my current compiler results:

<br />
QWriteLn('Hello')<br />
<br />
Results in:<br />
<br />
'ex<br />
QWriteLn<br />
's1<br />
Hello<br />
'e1<br />

This is what it means:

<br />
'ex           Execute the function below<br />
QWriteLn      This is the function<br />
's1           it's a string argument to the function which is on line 1<br />
Hello         This is what 's1 is referring to<br />
'e1           This marks the end for the function<br />

As you can see, this byte code can be understood (even if I hadn't explained it). How do I design a byte code that's hard to understand/decompile?