Working with a radio chip we selected because it had built-in encryption. Cannot make the encryption work, thus in contact with the manufacturer:
"- I cannot make the encryption work, it's like the chip doesn't want to take a key.
- which key do you use?
- does it matter?
- well yes, you can't just use any key!
- why not?
- you need to get an approved key from us.
- why is that?
- so that your competitors can't read your data!
- ...
- ...
- so the way to get working keys is to get them from you?
- of course!
- keys are 256 bits. Can we potentially use all of them?
- OF COURSE NOT!
- how many can we get from you?
- one! We reserve it from your company.
- are you telling me that all units within a company will need to have the exact same encryption key?
- yes!
- so anyone with our product could eavesdrop another same product?
- well yes, but it's all within your own products.
- ...
- ...
- that's not how encryption is supposed to work.
- but it's safe, your competitors cannot eavesdrop!
- I'm out of here."
(We finally found a satisfactory work-around, but i am still pissed at them)