← Privacy Guides

Communications

Private voice and video calls

An ordinary phone call or SMS is not end-to-end encrypted: your carrier, and anyone who can reach the phone network, can access the content and the record of who called whom. Moving your calls to an end-to-end encrypted app fixes the content; this guide explains what that does and does not hide, and how to reduce what still leaks.

  • Medium threat
  • Time 25 minutes
  • Difficulty Moderate
  • Last verified

What this protects, and what it doesn't

Protects

  • Call and message content: an end-to-end encrypted app (Signal, WhatsApp, FaceTime) means the provider and the network cannot hear your calls or read your messages.
  • Carrier access to content: a conversation moved into an end-to-end encrypted app is no longer handled by the carrier in a readable form (though metadata and your IP exposure remain).
  • With Signal, your IP address from the other party: Signal can route calls through a relay so the person you call does not learn your IP.

Does not protect

  • Metadata is not fully hidden. Even with encryption, providers keep some record — for example Apple says it retains limited FaceTime data (such as who was invited to a call and device network information) for up to 30 days. Who you talk to, and when, is harder to hide than what you say.
  • Regular cellular calls and SMS stay exposed. If either side falls back to a normal call or text, that leg is not end-to-end encrypted and the carrier can access it.
  • Your phone number is an identifier. Number-based apps reveal that you are reachable at that number unless you take extra steps to separate it.
  • The endpoints still matter. A compromised phone, a screen recorder, or someone beside the other person defeats any encryption.
  • Group calls and features vary. Confirm each app's current behaviour for group calls and linked devices rather than assuming.

Prerequisites

  • A smartphone or computer that can run an end-to-end encrypted calling app.
  • Agreement from the people you call to use the same app — encryption only applies when both ends use it.

Step by step

  1. Know what a normal call exposes

    Standard SMS text messages are not end-to-end encrypted: CISA states plainly that “SMS messages are not encrypted” and that someone with access to a carrier’s network can read them. Standard cellular voice calls are likewise handled by the carrier in a form it can access. That is why CISA’s 2025 mobile-communications guidance — written mainly for highly targeted people, but, it says, applicable to everyone — recommends using end-to-end encrypted apps such as Signal for sensitive calls and messages. The fix is not to harden the phone call — it is to move the conversation into an encrypted app.

  2. Choose an end-to-end encrypted app

    Pick based on who you need to reach and which platforms they use:

    • Signal: end-to-end encrypted voice and video, run by a non-profit, open-source, and designed (Signal says) to collect as little metadata as possible. The best default for privacy; see Signal hardening.
    • FaceTime (Apple): Apple states FaceTime calls are end-to-end encrypted and that Apple cannot listen in. Convenient between Apple devices, but Apple keeps limited call metadata for up to 30 days.
    • WhatsApp: calls are end-to-end encrypted and it is widely installed, so it is often the practical choice; note it is owned by Meta and collects more metadata than Signal.

    Whichever you choose, the protection only applies when both people are using the same encrypted app — a call that drops to cellular is back in the clear.

  3. Hide your IP address on Signal calls

    By default Signal routes calls from people who are not in your contacts through a relay server, which hides your IP address from the other party. For calls with contacts, Signal connects more directly for quality unless you turn on Always Relay Calls (Settings → Privacy → Advanced), which sends every call through the relay (this may reduce call quality). Turn it on if you do not want any caller to learn your IP address.

  4. Separate your identity from your phone number

    Number-based apps tie you to your phone number. To reduce that linkage:

    • In Signal, set a username so you can connect with people without giving out your phone number (you still need a phone number to register), and review the phone-number privacy settings (Settings → Privacy → Phone Number) that control who can see it and who can find you by it.
    • Where you need a number you can hand out without exposing your real one, a separate secondary (VoIP) number can act as a buffer — but remember the VoIP provider then sees those call records, so it moves the trust rather than removing it.

    Decide this by your threat model: for most people a username plus sensible number-privacy settings is enough.

  5. Keep the whole call encrypted

    Encryption only helps if the whole conversation stays inside the encrypted app. Agree with the other person to call within the app rather than "just phoning"; do not read sensitive things aloud where they can be overheard or recorded; and keep both devices updated and locked, since the endpoints are where any attacker has the easiest path.

Common mistakes

  • Treating a normal cellular call or SMS as private; neither is end-to-end encrypted.
  • Assuming an encrypted app hides who you called — content is protected, but some metadata is retained by the provider.
  • Letting a call fall back to the carrier network (a dropped app call continued as a normal call) and assuming it is still encrypted.
  • Giving out a number-based identity and expecting anonymity; set a username and number-privacy settings, or use a separate number.
  • Hardening the app but ignoring the phone itself, where a compromised or unlocked device defeats everything.

Going further

Calling privacy sits alongside messaging privacy: see Messaging apps compared and Signal hardening. Because your phone number is the identifier most of these apps use, protect it with Defend against SIM swaps. For the highest-risk situations, read High-risk messaging.