Pickbox is a client-server suite that provides directory syncing across computers. It utilizes convergent encryption to achieve security and file de-duplication.
Both user account name and password are stored locally and remotely, though there are some slight differences.
User account name is stored in plain-text format locally, while the password is encrypted in AES-256-CBC with user account name as encryption key. Both are saved into .pickbox.yaml located in user's home directory.
On the other hand, PBKDF-256 algorithm is used to generate content hash of user account name and password during registration, then the results are tranferred to remote server. Remote Pickbox server will stored them in a SQLite database as authentication tokens for future API usage.
During syncing, Pickbox will use AES-256-CBC algorithm to encrypt each file. The SHA-256 hash of the content of each file will be used as encryption key. Such method can eliminate file duplications on server since identical files would share exactly same cipher. Then the SHA-256 hash will be encrypted in AES-256-CBC while using user's password as encryption key and stored locally.
The encrypted cipher would be uploaded to server and stored as individual file while using another SHA-256 hash of cipher itself as filename.