Chat with a friend.

Private conversations. Simple controls.

DeXCHAT supports private two-person chats and groups of up to 8 people. Group creators manage membership and must stay online. New participants receive no previous messages. Removing a participant refreshes the group keys and invalidates the old invitation; create a fresh invitation for new members. Create a chat and share an encrypted invitation, or join a friend with a link, ZIP, or full chat code. Invitations from earlier releases are unsupported; update both clients and create a new chat with a fresh invitation. Windows and browser clients support text, images up to 10 MB, and files up to 25 MB. Voice messages use interoperable PCM WAV; microphone recording is available in the Windows app and an HTTPS browser. A local HTTP browser can receive voice messages, but browsers normally refuse microphone recording there.

Both chat modes use wss://chat.duxalife.com automatically. In the Windows app, choose “In the same Wi-Fi” to start a local relay inside the app. A phone on the same network can open the compact LAN link directly to join; Windows Firewall permission may be needed. The link serves an HTTP page with weaker page security and requires an explicit acknowledgement before entering a password. Local WS invitations cannot connect from this HTTPS website.

What protects the chat?

DeXCHAT uses one current protocol with two-person and group modes. In two-person mode, XChaCha20-Poly1305 encrypts and authenticates message payloads; ephemeral X25519 and signed Ed25519 handshakes establish the session. Argon2id protects invitation and profile passwords; HKDF-SHA256 derives session keys. Message chains advance, periodic key refresh exchanges fresh X25519 material, and replay checks reject reused packets. Group mode uses an owner-signed membership roster, pairwise X25519 key envelopes, and per-sender authenticated encryption and Ed25519 signatures. Membership changes create a new symmetric group-key epoch. Removing a person also replaces the admission secret and revokes old invitations. This is not Signal or MLS and does not claim full post-compromise security. Internet connections use WSS/TLS. The relay forwards encrypted packets without their decryption keys or an offline queue.

Invitations pin the creator's identity. Compare the six safety emojis and full fingerprint with your friend through a trusted conversation, then confirm this session. Display names do not prove identity. Both participants must stay online. Closing a session requires a new chat and invitation; this is not multi-device account synchronization.

Files, voice, and real privacy limits.

Senders choose whether the normal Download button is available, whether an attachment may be opened or listened to once, and whether a timer removes it. Photos open in a full-screen viewer. Before sending, choose the default JPEG compression (quality 88%, longest edge up to 2560 pixels) or the original and compare sizes. Conversion stays in memory and accepts decoded images up to 36 megapixels. Original bytes may include camera metadata; unsupported images or originals above 10 MB are sent as files up to 25 MB. Connection, membership, key changes and verification appear in the conversation. Compare keys explicitly; refreshing keys does not verify identity. One-time content is removed from this client's temporary buffers and Blob URLs after opening/closing or playback; the sender receives an encrypted consumption receipt. A hidden Download button, screen-capture protection in supported Windows environments, and cleanup are best-effort client controls. A browser cannot reliably detect or block screenshots, recording, developer tools, another camera, or a recipient who modifies their client. Do not share content on the assumption that it cannot be copied. Arbitrary files are never executed or embedded in the browser; a restricted file with no safe preview shows metadata only.

Your data stays under your control.

Messages are not automatically saved. Browser keys live in a disposable worker; there is no app storage in localStorage or IndexedDB. A compact LAN link downloads only an encrypted invitation ZIP from the same local server; passwords, plaintext, and keys are not sent to the HTTP server. The HTTP acknowledgement and downloaded invitation stay in memory. Desktop profiles and exported files are saved only when you choose a folder. “Erase everything” clears app-managed data in selected export folders and can remove the compiled EXE and its bundled installer/checksum. It preserves unrelated files. Reselect older export folders to include them.

Deletion is not guaranteed forensic erasure. Windows may page memory, the packaged app extracts native libraries to a temporary folder, and backups or copies elsewhere remain outside its cleanup. A compromised device or website frontend can expose plaintext and keys; network participants can observe connection metadata. HTTP allows page tampering that can expose the invitation password, plaintext, and encryption keys despite strong end-to-end algorithms. This risk cannot credibly be expressed as a percentage, and fingerprint comparison alone cannot prove an HTTP page is authentic.

What's in the Windows download?

DeXCHAT.exe, the official Microsoft Visual C++ x64 Runtime installer, checksums, and a short start guide. Extract the ZIP and open DeXCHAT.exe; Python is not needed. Install the included vc_redist.x64.exe if a runtime is missing. Version 0.8.2, Windows 10 / 11 x64, 42.3 MB.

This release is unsigned. The custom protocol uses PyNaCl/libsodium primitives and has not received an independent cryptographic audit. Nuitka compilation and selected constant obfuscation raise inspection effort; they do not make the client impossible to reverse engineer.

ZIP checksum · Microsoft runtime documentation