Reading your post and I had come up with something similar a few years back. Adding my notes below but I dont have the skills to put it together. Kind of wish there was a commercially available system with the same security measures.
There is a huge demand for devices like this in some places. I dont condone it but in South Korea these are very often used in womens bathrooms (so much so that in Seoul, there are teams that check the bathrooms daily).
This would also be good for deployment as a trail cam or security cam. In any role I can see a benefit in separating the device from the owner. If found even a thorough forensic analysis should not provide any useful information that would aid in identifying whomever placed it.
Hardware:
- Raspberry Pi or Arduino
- Camera module
- Cellular data module
- IR motion sensor (or software based?)
- Tamper-resistant self-destruct module (simple, voltage/current driven, massive power surge)
- Power source and backup battery
- Enclosure
Software:
- Base OS
- Tor or similar?
> Need to upload images / video files to secure location (Tor?)
> Files uploaded should be encrypted regardless of storage site
- Camera control
- Encrypted storage (how to unencrypt device in case of reboot once deployed)
- File management
- Communications management
This is pretty much an uneducated sketch of a system but I sure as fuck dont have the skills to put this together. If I were to try it would be by hacking together the hardware, and then combing through Github and other sites to find packages that might work and trying to make them work together.
If I were to attempt something like this the outcome would be horrifically unsecure I'm sure.