https://en.wikipedia.org/wiki/Private_Use_Areas
I came across a Python library that passed the ASCII range into one of these non printable character ranges and then into a database. If someone was doing that manually with a hex table, how is that detected and mitigated?
Not necessarily. Turn this around. Let’s say I am working at somewhere like a chip foundry with tons of IP. I have no access to encryption tools, but I can easily shift characters to a hex range in bash and send emails.
These characters can use the control glyph, and so do not print or show up in any physical way except in hex.
This technique must be obfuscated at every serious organization from governments to industry.
Encryption exists manually. This isn’t the problem you appear to imagine it is