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Secfone basic — User Manual

As of: 2026-08-13. For users of the mobile app (Android/iOS) and the Office client. Technical background: Architecture.

1. What is Secfone basic?

Secfone basic is an app for eavesdrop-proof communication — calls, conferences, video, chat, voice messages, files/photos, secured email and contacts. Everything is end-to-end encrypted: only the participants can read/hear the content, never the server. During a call, the keys are automatically renewed every 60–120 seconds, and the encryption is already designed to withstand future quantum computers ("PQC").

2. Getting Started

  1. Install the app and open it.
  2. Choose a language — the first, mandatory step (default English; 12 languages including Arabic with right-to-left support). The selection is applied immediately to the sign-up flow (Welcome, Code, Attestation, Alias, Done — including RTL for Arabic) and is saved for later. Use the language chip at the top to change it at any time.
  3. Accept the invitation: Scan the QR code or enter the code, or paste it from the clipboard (the format SEC-INV-XXXX-XXXX is checked for plausibility). You received the invitation from whoever invited you (e.g. by email/WhatsApp) — Secfone never learns who you are in the process.
  4. Secure the device (Attestation): The app generates hardware-bound keys in the Secure Enclave / StrongBox and checks your device (self-test).
  5. Alias & number: Enter your name as an alias — this is how others see you in the address book. You receive your Secfone number.
  6. Set up app lock: PIN and, if available, Face ID / fingerprint; a duress PIN (an emergency PIN that wipes the data vault under coercion — see section 7) is also recommended.

Use "Back" (the arrow at the top left or the system back gesture) to go back one step at any point during sign-up.

Your Secfone number (e.g. SEC · 4021 884) is your phone number within Secfone — it has nothing to do with your mobile phone number.

3. Contacts & Contact Directory

  • The Contact Directory lists the contacts released by your group/tenant — marked with a green ✓ "verified". New members automatically receive the contact directory when they join.
  • Joining as a new member: A new participant posts a brief introduction/communication request in the group chat. Only once the four-eyes principle is satisfied (1 admin + at least 2 users or 2 admins confirm) does the person receive the link between name and connection data — and become reachable.
  • Reachability: You are only reachable for permitted contacts (depending on your settings: only your groups, only the contact directory, only approved requests).
  • Groups: Contacts are organized into groups, which you can expand; a contact can belong to multiple groups, while others are individual contacts. Collapsed, you see a member preview (alias + picture) and the person in charge; expanded, you see the member list and — as a group admin — "Invite new member" (QR) and "Edit group".
  • Edit group (as admin): Change the name, add existing contacts or invite new ones via QR, remove members via the ⋮ menu or designate them as deputy (second group admin). The first person added afterward automatically becomes deputy. Only "Save" applies the changes permanently.
  • Multiple devices: A contact can have several devices and phone numbers; you reach the person, not a single device.

3a. Search (Content · Date · Filter)

At the top of the Chats tab, the search bar opens global search. You can search by content (message text), name, and date, and filter using chips:

  • Date: All · Today · This week · Last week.
  • Type: All · Contacts · Messages · Calls · Attachments · Voice.

Results are grouped by Contacts / Messages / Calls and are timestamped; tapping opens the chat or places the call. This lets you find, for example, "all attachments from this week" even without a search term.

4. Messages, Voice Messages, Files & Photos

  • Chatting: as usual, but end-to-end encrypted.
  • Unread counter: In the chat list, a red bubble shows the number of new messages. As soon as you open the chat (read the last message), the counter is reset.
  • Pin important chats: So nothing important gets missed, the list sorts pinned chats to the top, followed by unread ones, then the rest by recency. To pin/unpin, long-press the chat (📌).
  • Voice message: Hold down the microphone button, speak, send. Playback only within the app.
  • Send photo/video: Capture using the in-app camera (does not end up in the device gallery) or choose from the gallery. Location/camera data (EXIF) is automatically removed before sending.
  • Choose attachment: While writing, you can choose attachments — from the in-app camera, your encrypted area, or from the device's files/photos.
  • Receive & decrypt: Received messages/attachments are initially stored in the encrypted area. After decrypting, you can deliberately store or copy normal content into the unprotected area (e.g. to paste it into a regular email). From that point on, it is no longer protected. Self-destructing and "view once" content cannot be exported; your administrator can disable export/forwarding.
  • Self-destruction / "View once": Disabled by default; you enable it per message (timer or "view once"). Afterward, the message and any attached file are removed without a trace from your and all recipients' devices — cryptographically destroyed, not recoverable.

5. Calls, Conferences, Push-to-Talk & Video

  • Secure call: Tap a contact → "Call". In the dial screen, start the call with the green call button; use ✕ at the top to cancel. At the top you see "Secure call" and the call duration.
  • Hang up without returning: After hanging up, you stay in the dial screen (standby) — you can call again immediately or go back with ✕.
  • Visible key renewal: During an ongoing call, the green badge shows "Key renewed · X s ago" as well as round N · initiated by your device / the other party — participants alternate in triggering the new key round.
  • Two calls / switching: If you start a second call, the first one is held. At the top, "Switch to … · held" appears — a tap toggles between the two.
  • Request callback when free: If the person you're calling is busy, tap "Request callback when free" in the dial screen — you'll be notified as soon as the person is reachable again.
  • Verify (SAS): On first contact, you can briefly compare the displayed security code ("SAS 47 · 12") out loud — if it matches, there is guaranteed to be no eavesdropper in between.
  • Conference: multiple participants; for larger groups this is handled automatically via a relay that still cannot read anything.
  • Return (minimize call): Use the arrow at the top left (˅) to jump back into the app while the call continues — the call keeps running in the background. A green bar with the duration appears at the top; tapping it takes you back into the call. You can only end it via Hang up.
  • Push-to-Talk (PTT) in a group: Contacts → expand group → "Push-to-Talk (group)". Walkie-talkie mode: hold the large button, speak, release. Only one person can speak at a time — if the channel is free, you get it immediately (vibration); if it's busy, you see "X is speaking" and can join the queue by holding the button. With Priority (dispatch) you can take over the channel even while it's busy.
  • Video conference: Contacts → expand group → "Video conference". You see the participants as tiles (active speaker highlighted), your own picture small on the right, and Mic/Camera/Share/Invite/Leave at the bottom. Use the arrow at the top to jump back into the app (the conference keeps running).
  • Push-to-Video: In the PTT channel, you can enable "Send with video" — then your picture is also transmitted while you speak (still only one person at a time).
  • Video & screen sharing: like a call, with camera or shared screen.

5.2 Call History

In the Calls tab, you see your calls with a full timestamp — grouped by date ("Today", "Yesterday", "This week", "Last week", "Older") and shown per entry as Today 09:32 / Yesterday 14:10 / Tue 08:12 / Aug 12, 09:00. Each entry shows direction (outgoing/incoming/missed), video, and duration. At the top, you can search by contact and filter with the chips All / Missed / Video; missed calls are shown in red and summarized as a counter at the top. Tapping calls the contact back directly.

5.1 Incoming Call While Already on a Call

If a Secfone call reaches you while a WhatsApp or regular mobile call is already in progress, by default:

  • The caller hears a busy signal ("participant busy").
  • You see an on-screen notice: "Incoming Secfone call while a call is in progress", and find the call marked as missed in the call list; after hanging up, the app offers you a callback.
  • Optionally, you can enable "Call waiting" in settings — then the Secfone call is offered as a second call instead of "busy".

5a. Documents / Data Vault (Protected Area)

The Documents tab is your encrypted data vault on the device:

  • Folders & files: Navigate into folders (back arrow at the top), search within the current folder. Folders are shown at the top, then files with size and date.
  • Add (＋): New folder, New note (text), in-app camera, or import file — everything is stored encrypted.
  • View: Tapping opens the protected in-app viewer (no handoff to third-party apps, no OS backup, app switcher preview blurred).
  • Edit: Text notes can be edited and saved directly in the in-app editor (encrypted).
  • File menu (⋮): Open, Edit, Rename, Export to unprotected area, Copy (e.g. for email), or Delete. Export/copy deliberately leave the protected area — from that point on, the responsibility is yours.

6. Secured Email (Proxy for Outlook/Thunderbird)

Secfone can route your regular email through the closed, encrypted channel. To do this, your usual program (Outlook/Thunderbird) is configured once to use special local ports — the app helps with the setup. Note: for external recipients, protection only extends to the exit point; for full end-to-end security, use Secfone's internal messaging.

7. Everyday Security

  • Security profile (Settings): "Maximum / High / Standard" controls how strongly network traffic is disguised (more protection = more battery/data usage).
  • Screenshot protection: On Android, screenshots/recordings are blocked; on iOS you are warned and content is blurred.
  • App lock & duress PIN: In case of loss or coercion, the app protects your data. After several failed attempts, it can wipe itself.
  • Loss/theft: Report it to your administrator — your data vault can be wiped remotely.

8. New Phone (Device Change)

During a switch, your old device shows an export screen with a QR code; the new device scans it, you both confirm a comparison code, and your data moves across directly and encrypted. Only after a successful transfer is the old device wiped. No old device anymore? Then you'll need the optional recovery backup or a new activation by your administrator.

9. Changing the Language

Settings → 🌐 Language → select the desired language. Arabic is displayed right-to-left.

10. Frequently Asked Questions

  • Why doesn't it ring when I'm already on a call? For security reasons, Secfone reports "busy" (see 5.1); enable "Call waiting" if you'd prefer it handled differently.
  • Can the server see my calls? No — only operational data (that/when a connection exists), never content or keys.
  • Is my name stored? Names are kept separate from the numbers and are only linked on authorized devices.