After enabling CSFLE for my python application, how do i encrypt the older data<data before the implementation of CSFLE>

Hi All,

I have been trying to implement CSFLE for my python application using the Flask framework. After going through Client-Side Field Level Encryption — PyMongo 3.12.0 documentation I was able to successfully implement CSFLE for my application using two approaches:

  1. Providing Local Automatic Encryption Rules: Using this I was able to encrypt new data that was being added and the older data is also rendering for the same collection but the older is not encrypted, I looked into the internet for the answer and this topic was nowhere to be found at least up to my knowledge, so if there is some documentation on how we can encrypt older application data after enabling CSFLE it would be really great.
  2. Server-Side Field Level Encryption Enforcement: As server-side schema is more secure thus I tried this approach as well and was able to achieve CSFLE but during the initialization in this approach as per the doc, the collection is deleted and created again thus the older data is getting deleted.

Is there a way to not delete the data in the first place and then again like in point no 1, is there a way to encrypt older data after enabling CSFLE.

Any help or pointer to any documentation that can be useful would be greatly appreciated.

Thank you.
Deependra Thagunna