Privacy Messenger Comparison
An honest look at how ZChat compares with Signal, Session, and SimpleX across 16 axes. We believe transparency builds trust.
| Feature | ZChat | Signal | Session | SimpleX |
|---|---|---|---|---|
| Identity requirement | None (Zcash address from seed phrase) | Phone number | None (Session ID) | None |
| Message transport | Three per-conversation modes: Zcash shielded memos, or NOSTR relays (Tunnel is the default) | Signal servers (centralized) | Lokinet (decentralized onion routing) | SimpleX relays (federated) |
| Message storage | On device; on-chain permanently in Shielded mode, otherwise relay queues (30 days on ours) | Device only (ephemeral on server) | Swarm nodes (temporary) | Relay queues (temporary) |
| On-chain metadata hidden | Yes (Orchard shielded pool; timing and size still public) | N/A (no blockchain) | N/A | N/A |
| Server sees metadata | Relays see recipient key + timing (30 days on ours); TURN sees call metadata; backend and lightwalletd see IP (7-day logs). Never content or sender. Two third-party relays on by default | Minimal (sealed sender) | Minimal (onion routing) | No user identifiers |
| Forward secrecy | No (persistent ratchet root; double ratchet designed, not shipped) | Yes (Double Ratchet) | No | Yes (Double Ratchet) |
| E2E encryption | ECDH P-256 + HKDF + AES-256-GCM | Signal Protocol | Session Protocol | Double Ratchet |
| Third-party audit | None ever (audit planned for Q4 2026) | Yes (multiple) | Yes (Quarkslab 2024) | Yes (Trail of Bits 2024) |
| Open source | Yes (MIT) | Yes (AGPLv3) | Yes (GPLv3) | Yes (AGPLv3) |
| Group messaging | Yes (signed admin controls) | Yes | Yes | Yes |
| File sharing | Yes | Yes | Yes | Yes |
| Voice / video calls | Yes (WebRTC, DTLS-SRTP) | Yes | Yes (voice) | Yes |
| Platforms | Android only (direct signed APK, not in app stores) | Android, iOS, Desktop | Android, iOS, Desktop | Android, iOS, Desktop |
| Payments built-in | Yes (ZEC) | Previously (MobileCoin, removed) | No | No |
| Dead Man's Switch | No | No | No | No |
| Remote data wipe | Yes (opt-in duress wipe, off by default) | No | No | No |
Who should choose what?
Every messenger makes trade-offs. Here is our honest take on who each option serves best.
Signal
Recommended for most people. Battle-tested, widely adopted, supports all platforms. If you need a secure messenger today, use Signal.
Session
Best for users who want decentralized messaging without phone numbers and don’t need forward secrecy. More mature than ZChat.
SimpleX
Best for maximum server-side privacy. No user identifiers at all, even at the protocol level.
ZChat
Best for Zcash users who want messaging integrated with ZEC payments, or anyone who wants the option of carrying a conversation as shielded on-chain transactions. Android only, no third-party audit yet, and no per-message forward secrecy.
This comparison was last updated in September 2026. We are committed to keeping it accurate. If you spot an error, please open an issue on GitHub.