Strategies for Encryption with Django + Postgres?
I agree that first you need to consider your overall security model and what threat avenues might be the most risk, a la this article:
but also take a look at these for encrypted fields in Django:
encrypted fields: https://github.com/svetlyak40wt/django-fields
more encrypted fields:
https://github.com/defrex/django-encrypted-fields,https://github.com/django-extensions/django-extensions
What are you protecting against? If attacker would get access to your DB/filesystem, he would find how you decrypt data & keys. Hiding your encription key is not an easy task (and rarely implemented in "usual" applications).
I would spend more time on protecting the server and fixing all general security issues.