I'm looking for a client-side encryption implementation that would be able to secure CardDav & CalDav data so that they couldn't be compromised even by the hosting provider.
- Server side: PHP or Python based Web application implementing CardDav & CalDav
- Client side: Desktop E-mail client & mobile client with CardDav & CalDav support
Client 01 --> WRITE data (data encryption)--> CalDav/CardDav Server
Client 01 <-- READ data (data decryption)<-- CalDav/CardDav Server
Client 02 --> WRITE data (data encryption)--> CalDav/CardDav Server
Client 02 <-- READ data (data decryption)<-- CalDav/CardDav Server
The purpose is to ensure confidentiality of the data (contacts, calendar events) on the server in order to keep private information secure from potential eyes-dropping. The goal is also that the data on the server can be accessed by multiple clients AND users.
Do you know if such a thing actually exists & can you provides examples of implementation?