Private Messaging: Choosing How You Communicate

Private communication starts with an ordinary need: catching up with family, talking without handing out a phone number, or reaching someone nearby when internet access is unavailable. You can choose a useful tool without moving every conversation at once. Where identity checks are part of getting connected, separate what the messaging app needs from what the underlying mobile service requires.

Choose the conversation first, then the identity and connection it needs. Signal, White Noise, SimpleX, Briar and Bitchat offer different routes, not a single privacy league table. Start with one willing person and a non-sensitive test message.

This guide describes the projects' documentation checked on 7 November 2026. It is not an installed-app review; delivery, settings and cross-platform behaviour have not been tested here.

A small map of the options

Download links below lead to official project download pages or repositories linking their releases and stores. Platform listings are not promises of feature parity.

App / official downloads	Platforms documented	Signup identity	Connection	Private conversation versus public space
Signal	Android, iOS; linked Windows, macOS, Linux desktop	Phone number; optional contact username	Internet	Messages and calls end-to-end encrypted
White Noise	iPhone, Android	Nostr key-based identity; no phone/email	Internet relays	Encrypted conversations; public profile
SimpleX	Android, iOS, Windows, macOS, Linux	Local profile; no phone/email or network-wide user ID required	Internet servers	Direct chats/groups end-to-end encrypted; channels are not
Briar	Android mobile	Local nickname/password; no phone/email	Tor internet; nearby Bluetooth/Wi-Fi	Private chats/groups; forums have a wider audience
Bitchat / Android	iOS, macOS; Android implementation	No signup/phone number; device keys still exist	Nearby Bluetooth LE; separate internet Nostr routes	Private mesh messages use Noise; public broadcasts/channels are public

1. “I want everyday private chats”

Signal is an option when phone-number registration suits both people. Per its current support docs, registration still requires a number that can receive verification by SMS or call. A username lets someone initiate contact without you giving them that number; it does not replace registration.

For a first test, install from the official download page, create an optional username, and exchange its link or QR code with your partner. Review Settings → Privacy → Phone Number for visibility and discovery. The username guide explains both controls, including that existing number-based and username-based chats can merge. Hiding a number does not make a previously known relationship disappear.

Signal says messages and calls are always end-to-end encrypted. Compare safety numbers, ideally in person, before relying on a contact's identity. Its privacy policy still describes registration data and technical material such as authentication and push tokens. Content protection is not a claim that no service data exists. Desktop requires Signal on a phone first.

2. “I don't want phone-number signup”

White Noise offers private conversations using Marmot, which applies Messaging Layer Security (MLS) to messaging over Nostr. Per its FAQ, no phone number or email is required. For a first test, create a test profile and exchange a profile link or QR code, not a private key. Start a conversation with your partner rather than publishing a public post in another Nostr app.

Its privacy policy, updated 13 October 2026, distinguishes encrypted conversation messages and media from public profiles and profile pictures. Relays carry encrypted events but can observe IP addresses, timing and event metadata; media servers can see upload/download connections. Optional push notifications add notification-token handling. Decide separately whether to enable telemetry or diagnostic-log sharing; they are not the same thing.

Published independent work exists: a Marmot specification review, an MDK library audit and a whitenoise-rs backend audit. Those are scoped, dated reviews, not blanket certification of every current app build. The FAQ also cautions that importing an identity on another device does not synchronize chat history or encryption state.

SimpleX takes another approach: per its project documentation, delivery uses connection-specific queue addresses rather than a network-wide user identifier. That does not mean there are no identifiers anywhere. Its quick start creates a local profile without phone/email registration. Create a one-time invitation for your partner, exchange the link or scan its QR code, then compare the conversation's security code.

The privacy guide says direct chats and groups are end-to-end encrypted. Channels are different: chat relays can read channel messages, including channel chats with admins. Choose a direct chat for this exercise. Private message routing reduces IP exposure to recipients' servers, but do not assume every feature follows a proxy: the guide explicitly says calls connect without the SOCKS proxy. Start with text; examine call routing separately if IP protection matters.

3. “We need to communicate nearby without internet”

Briar, per its manual, creates an account locally with a nickname and password. On two Android phones, add each other nearby by scanning each other's QR codes. Open the contact's private chat for a non-sensitive exchange, then explore the documented Bluetooth/Wi-Fi connection options together.

Its design synchronizes directly between devices: Tor for internet communication, Bluetooth or Wi-Fi nearby. Tor helps protect network relationships; nearby radios remain a different exposure surface. Briar encrypts device-to-device communication end to end, including forum synchronization. That does not make forums private groups: the manual calls forums public conversations and lets members invite others. Without a reachable local connection, Briar does not become a nationwide offline network.

Bitchat documents Bluetooth Low Energy discovery and multi-hop relaying without signup or internet for the local mesh. Use the official Apple-project README or Android README to reach downloads. With a nearby partner, distinguish a private message from the public mesh conversation before sending even the test text.

Per its security policy, private mesh messages use Noise encryption, while mesh announcements and geohash channels expose public content, nicknames and public keys. Nearby observers can detect Bluetooth presence; the README also documents a persistent device identifier derived from an identity key. Nostr geochannels need internet, and private Nostr fallback uses Bitchat's own envelope format, not ordinary Nostr-DM compatibility.

The Android README additionally lists Wi-Fi Aware on supported hardware and platform-specific permissions. Do not infer identical features from cross-platform mesh compatibility. A current independent audit covering the shipped apps was not established by the sources checked; a security-reporting policy is not an audit.

A few useful words

• End-to-end encryption: content is encrypted for the conversation's participants, not the transport operator. Audience still matters: public channels are not private chats.
• Metadata: information around a message, such as connection addresses and timing. See network privacy and Tor.
• Relay: a server that receives and forwards events. Choosing relays changes delivery dependencies, not the meaning of encryption; see Nostr relay lists.
• Private identity key: the secret controlling a cryptographic identity, not proof of a person's legal identity. See Nostr keys and signers. Never send private keys to a contact.

Identity checks are a separate layer

In Australia, ACMA’s guidance, updated 21 September 2026, describes existing identity checks when activating prepaid mobile service. The enacted determination, compiled on 16 December 2025, provides several verification methods and specific exemptions. This determination concerns prepaid mobile-service identity verification; it does not impose identity checks on every messaging app or a blanket biometric SIM requirement.

South Africa, a dated draft case: its Gazette 55631, Notice 4217, dated 28 October 2026, proposes biometric subscriber verification and a five-number limit per subscriber per operator. This document is a draft, not enacted law. It allows 30 working days for comments; ICASA's announcement abbreviates that to “30 days.” Its records-retention clause mentions 30 days after deactivation with qualifications involving law, contract or consent—not unconditional deletion. The global distinction is useful: an app without phone-number signup changes what the app asks for, not the registration rules of the internet or mobile service carrying it. Wi-Fi internet still relies on an access provider; encrypted chats do not make network or device metadata disappear.

What this is not

This is not an anonymity ranking, legal exemption, security certification or emergency plan. Nearby communication needs working devices, permissions and reachable peers; no range, blackout safety or delivery guarantee is offered. Recipients can retain messages, and compromised devices can expose them. Choose one ordinary conversation, try it together, and use the one-page threat model when your needs become more specific.

Related on CryptoDecentral

• Privacy pillar
• Network privacy: Tor and I2P
• Nostr keys and signers
• Nostr outbox relay lists
• A one-page threat model