Operalytix How it works and privacy
How it works, and who learns what.
Operalytix assumes that relays, push services, network observers and Apple may all act against you. This page shows how a message travels, and what each of them can still see.
The path of a message
Five steps, no account anywhere.
Your phone encrypts
MLS encrypts the message for the chat’s members. Keys are agreed with ML-KEM-1024 plus P-384 and signed with ML-DSA-87 plus Ed25519.
A sealed envelope
The result goes into a sealed-sender envelope (HPKE, RFC 9180) of exactly 16 KiB. Attachments travel in 64 KiB chunks.
Through Tor
Each relay request uses its own Tor circuit, and is sealed again to a key the relay’s pinned identity signs.
Held by a relay
The relay keeps the envelope in a mailbox for up to 14 days. Mailbox names change as the group’s keys change.
Opened by the recipient
The recipient’s phone fetches the envelope through Tor, and only it can open it.
The layers
What each layer of encryption is for.
No cryptography is home-made: Operalytix uses established, open-source libraries and documents every choice.
Message encryption (MLS)
OpenMLS with a private hybrid suite: ML-KEM-1024 + P-384 key agreement, AES-256-GCM, SHA-384, and composite Ed25519 + ML-DSA-87 signatures. A one-to-one chat is a two-member group.
Sealed sender
Every message is wrapped in an envelope that only the recipients can open and that is always the same size, so a relay sees neither who sent it nor what kind of message it is.
Relay requests
Requests to relays are sealed with ML-KEM-1024 + P-384 to the relay’s signed key, on top of Tor. Mailboxes are opened with a mailbox key, not an account, and writing to one costs a proof of work.
Transport
Tor runs inside the app. Tor’s own handshakes are classical, not post-quantum.
Storage on your phone
Every database row is sealed with XChaCha20-Poly1305 under a key wrapped by the Secure Enclave, and files use iOS Data Protection Complete.
Who learns what
What each party can and cannot see.
This is the same list the app shows and that our store listing uses. If something here is wrong, it is a security bug.
A relayStores and forwards envelopes
Does not learnMessage content, the sender, any account (there are none) or your IP address.
Can learnWhich of its mailboxes are read and written and when, and how many envelopes a message takes. It can follow a chat’s activity over time, see which mailboxes one device reads together, and drop or delay traffic.
Your network providerWi-Fi, mobile carrier, a local observer
Does not learnWhich relays or contacts you talk to, or what you send.
Can learnThat you use Tor (or a bridge), when, and roughly how much. Cover traffic runs only while the app runs, so when you use the app stays visible.
A call server (TURN)Relays call media
Does not learnWhat is said or shown in a call.
Can learnIn private mode (default): a Tor exit, and the call’s timing, duration and volume. In fast mode (opt-in): also your device’s IP address.
The push gatewayOnly if you turn push on
Does not learnMessage content or senders. Pushes carry neither.
Can learnYour Apple push token, under a random reference, and when it sends pushes. In instant mode, working with a chat member or relay, it can link your token to that chat.
AppleDelivers pushes and crash logs
Does not learnMessage content.
Can learnWith push on, the Apple account behind the push token and when pushes arrive. With “Share With App Developers” on in iOS, crash logs, which it passes to us.
Your contactsThe people you write to
Does not learnAnything you do not send them.
Can learnEverything you send them, with a signature that lets them prove to others that you wrote it.
Us, the developerEvolves EOOD
Does not learnYour messages, calls or contacts.
Can learnWhat the push gateway learns, if you use push; crash logs from Apple if you share them; what you choose to send in a report; and, if you use a call server we run in fast mode, your IP address during the call.
Out of reach
What Operalytix cannot protect against.
- A compromised or unlocked phone, or malware running on it.
- A contact who takes screenshots or forwards your messages.
- Traffic analysis by an observer who watches large parts of the internet at once, beyond what Tor, padding and cover traffic make harder.
- Someone in the middle at first contact, if you never compare safety numbers.
- The prebuilt third-party components in the app (LiveKit WebRTC for calls, IPtProxy for Tor bridges), which are pinned by checksum but not rebuilt from source.