Z-TEXT goes public on October 5, 2026 . Before launch, here's how it works under the hood, and where its limits are.
No phone. No email. No SIM. Zero metadata.
## Identity: a seed, not a phone number
There is no signup. Your identity is a shielded address derived from a 24-word seed. The same seed unlocks five tools: a messenger, a BTCZ wallet, an on-chain password manager, Channels (on-chain broadcast) and disposable identities.
Lose the phone, restore the seed on any device, and your messages, contacts and vault rescan from the chain.
## The message path
1. The message is encrypted on-device with AES-256-GCM .
2. The key exchange is hybrid: X25519 + ML-KEM-768 (NIST FIPS 203), live since version 3.7.0, so traffic recorded today resists a future quantum computer. Signatures are still classical Ed25519.
3. The ciphertext is sent as the memo of a Sapling shielded transaction on BitcoinZ. zk-SNARKs prove the transaction is valid without revealing sender, recipient or amount.
4. It is pushed through the mempool for delivery in about 1–5 seconds, then settles on-chain.
No central message server holds the conversation. What exists on-chain is an encrypted, shielded transaction, not a readable transcript.
## Spam resistance through a micro-fee
Each message costs 0.0002 BTCZ : a 0.0001 network fee plus 0.0001 delivered to the recipient. In a normal back-and-forth that 0.0001 comes back with each reply. Negligible for people, expensive for bots at scale.
## Choose your trust tier
- Default: connect to the official lightwalletd. It sees that a shielded transaction was submitted, not who, to whom or what.
- Tor: the same, but the operator no longer sees your IP.
- Self-hosted: run your own lightwalletd or full BitcoinZ node. No third party in the loop.
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## Honest limits
- Text only: no files, pictures or video.
- No independent audit of the app yet. There is an active, paid bug bounty instead, but a bounty is not an audit.
- Permanence is a feature and a responsibility: messages settle on a blockchain.
## The chain
BitcoinZ launched on September 10, 2017, with no premine and no ICO. It is community-run and GPU-mineable. Z-TEXT does not issue or control BTCZ.
Launch day is October 5. Follow along at [ z-text.com ]( https://z-text.com ), and read about the chain at [ getbtcz.com ]( https://getbtcz.com ).
Questions about the design are welcome in the comments. 👇