[onion2k]

Encryption, so you learn something about how it works.

I would actively discourage developers from writing their own encryption software, in case they're tempted to use their work in a production app. Encryption is sufficiently complicated that you will get it wrong, and sufficiently important that getting it wrong will be very bad. Leave encryption to cryptographers.

[Zekio]

I didn't think about that they might use the one they make.

That would be bad, so maybe an obfuscator instead?