Hi everyone, I wanted to just address a few points that arise for decentralized and messaging apps:
How decentralized is Stealthy?
* User identities are stored in the Bitcoin blockchain
* User storage is decentralized away from Stealthy in the user’s own cloud storage
* Stealthy doesn’t require a centralized signalling server for p2p communication (both parties must add each other as contacts, coordinating this outside of Stealthy)
* Conveniently, Stealthy includes a signalling server that can be disabled.
* Push notifications use centralized technology at present.
* Our public discussion channels use centralized notifications to scale at present.
* We build on Blockstack to get decentralized identity and storage (https://blockstack.org/faq/, https://blockstack.org/whitepaper.pdf)
* We have plans to continue decentralizing Stealthy features as time permits and solutions become available, for instance migrating to GUN decentralized database for some features (https://gun.eco)
* We plan to publish more details near the end of this year.
* All data is stored off chain for performance approaching centralized messengers.
* Offline p2p communication is relatively simple and involves polling a contact’s cloud storage for messages.
* Polling scales based on users presently and will see more intelligence in a future release.
* Realtime p2p uses our offline p2p to establish a WebRTC connection (coming later this year to mobile).
* All p2p messages are encrypted client side before transmission.
* Our public channels use a hybrid version of our p2p protocol
* Messages from users use the p2p protocol with a centralized notification for scaling.
* Messages from the channel are written sequentially, unencrypted (it’s a public channel)
* Encryption keys are held by the user
* Stealthy uses Blockstack compatible ECIES for all p2p messaging (SECP256K1 curve, SHA512 MAC, AES 256 CBC cipher, SHA256 HMAC)
* More information here: https://blockstack.org/faq/
Stealthy was not designed to conceal metadata from state-level actors, especially those with a capability of surveilling each node of a network concurrently. There are other protocols with that intent. However, we are looking to improve our protocol in this regard in the near term.
5. Why collect an email?
Stealthy uses Blockstack’s identity solution which collects email in the event that you need to recover your 12-word Blockstack pass phrase. Stealthy does not collect your email.