There's not a lot of entropy in your obfuscation process, so it can be brute-forced.
Okay. Can you explain in a few more sentences exactly what this means? I am genuinely interested to know if this system can be broken easily. We all think we're very clever at coming up with unique ways to obscure our data.
We are wrong.
We tend to think alike, so pretty much any process you can think up is likely very similar to a process somebody else will think up.
In short: humans are really bad at creating randomness (aka entropy). And we're even meta-bad, because we THINK we're good at it.