StickerDocs is a secure, fun and affordable file and photo organisation and sharing, for people. This is the core on which the (closed-source) StickerDocs App runs.
We use the established, popular Libsodim library for all data encryption. We make use of both public-key and secret-key as well as the hashing and key derivation features from this library.
When you register an account with StickerDocs, your password never leaves your device. We generate a new cryptographic key for encrypting all your data, and we encrypt that key with a derived key from your password.
To mitigate against theft of login material from intercepting SSL devices/Man-in-the Middle, we use public key cryptograph, and requests are signed and unique to prevent tampering.
Since there is no centralised database each client has their own SQLite database and these databases are kept in sync through the use of Conflict-free Replicated Data Types (CRDTs).
StickerDocs is distributed under AGPL-3.0 license.
We are not making the app open source at this time to prevent unauthorised clones. You will have to take our word when we say all communications from the app go via this component.