How to Encrypt Phone Calls on iPhone and Android

By George Mutune   Published: 09/22/23   Updated: 10/09/26   8 min read
Cybersecurity

Short answer: to encrypt phone calls, call through an app with end-to-end encryption, such as Signal (iPhone and Android), FaceTime Audio (Apple to Apple) or WhatsApp. Regular cellular calls are encrypted only between your phone and the cell tower, so they are not end-to-end encrypted and your carrier can still access them.

Updated September 2026. We’ve removed apps and tools that no longer exist, including Skype, and added step-by-step instructions for encrypting calls on iPhone and Android.

Most people assume their phone calls are private. In reality, an ordinary cell phone call is only partly encrypted, and the protection ends inside your carrier’s network. If you want true cell phone call encryption, you need to use an app that offers end-to-end encryption.

This guide explains the difference and shows you how to make encrypted calls on any smartphone.

Are regular cell phone calls encrypted?

Partly. On modern 4G and 5G networks, your call is encrypted over the air between your phone and the cell tower. That stops casual eavesdropping on the radio signal.

But the call is decrypted inside the carrier’s network so it can be routed to the other person. That means it is not end-to-end encrypted. Your carrier, anyone with lawful-intercept access, and any attacker who breaks into the carrier’s systems could potentially access it. The same is true for VoLTE and Wi-Fi Calling: the connection to your carrier is protected, but the carrier can still see the call.

This isn’t just theory. In December 2024, CISA reported that Chinese government-affiliated hackers had targeted commercial telecom infrastructure, stealing customer call records and compromising the private communications of a limited number of targeted people. CISA then published mobile communications guidance. It urges highly targeted people to assume their mobile communications could be intercepted and to “use only end-to-end encrypted communications.”

What end-to-end encryption means

With end-to-end encryption (E2EE), your voice is encrypted on your phone and decrypted only on the other person’s phone. The keys stay on the two devices. The app company, your carrier and your Wi-Fi provider see only scrambled data.

Most secure calling apps use public-key cryptography to set up a fresh key for each call. Our guide to common encryption methods explains how these building blocks work.

Apps that encrypt phone calls end to end

AppWorks onCalls end-to-end encrypted?Notes
SignaliPhone, Android, desktopYes, alwaysOpen-source, nonprofit, collects minimal data. CISA names it as an example.
WhatsAppiPhone, Android, desktopYes, by default for personal callsUses the Signal Protocol. Owned by Meta, which collects more metadata.
FaceTimeApple devices onlyYesAudio and video calls between Apple users are end-to-end encrypted.
Regular phone appAll phonesNoEncrypted to the tower only. The carrier can access calls.

What about Skype? Microsoft retired Skype in May 2025 and moved users to Microsoft Teams. If an older guide recommends it, that advice is out of date.

How to encrypt calls on iPhone

Option 1: FaceTime Audio (Apple to Apple)

  1. Open the Phone or FaceTime app.
  2. Find the contact and tap FaceTime Audio (or the video icon for a video call).
  3. Make sure the call shows as FaceTime, not a regular mobile call.

According to Apple’s platform security guide, FaceTime audio and video are end-to-end encrypted, and Apple can’t decrypt them. This only works when both people use Apple devices. A normal call to an Android phone is not end-to-end encrypted.

Option 2: Signal

  1. Install Signal from the App Store and register with your phone number.
  2. Set a Signal PIN when asked. It helps protect your account.
  3. Open a chat with the person and tap the phone icon for voice or the camera icon for video.
  4. For sensitive conversations, compare your safety numbers in person or over another trusted channel. This confirms that no one is in the middle.

Option 3: WhatsApp

  1. Open a chat and tap the phone or video icon.
  2. The call screen shows it’s end-to-end encrypted.
  3. Turn on two-step verification in Settings > Account to protect your account.

Extra iPhone protections

How to encrypt calls on Android

Option 1: Signal

  1. Install Signal from Google Play and register your number.
  2. Set a Signal PIN.
  3. Open a chat and tap the phone or video icon to call.
  4. Verify safety numbers for your most sensitive contacts.

Signal-to-Signal calls and messages are always end-to-end encrypted.

Option 2: WhatsApp

  1. Open a chat and tap the phone or video icon.
  2. Turn on two-step verification in Settings > Account.

What about Google Messages and the Phone app?

The built-in Phone app places regular carrier calls, which are not end-to-end encrypted.

Google Messages protects texts, not calls. Google says RCS chats are end-to-end encrypted when everyone in the conversation uses Google Messages with RCS turned on. With iOS 26.5, RCS chats with iPhone users can also be encrypted on supported carriers. Look for the lock icon. CISA’s advice is to use RCS only when end-to-end encryption is on.

Tips for encrypted calls

Encrypted calling for businesses

Many business calling and meeting platforms encrypt calls in transit with TLS and SRTP. That protects calls on the network, but the provider may still be able to access them. Check whether your platform offers end-to-end encryption, whether it’s on by default, and which features (such as recording or transcription) turn it off.

For highly sensitive conversations, set a policy that staff use an approved end-to-end encrypted app. Pair it with phishing-resistant MFA and managed devices. Our roundup of cryptography tools covers encryption options for email, files and keys.

Encrypted email: The Enigmail add-on no longer works with Thunderbird. Thunderbird now has OpenPGP encryption built in, and many email providers support S/MIME.

For weekday updates on scams, breaches and new privacy features, sign up for the CyberExperts Daily Brief.

Frequently asked questions

Are cell phone calls encrypted?

Regular cell phone calls on 4G and 5G networks are encrypted between your phone and the cell tower, but not end to end. The call is decrypted inside the carrier’s network, so the carrier can access it. For end-to-end encryption, use an app such as Signal, WhatsApp or FaceTime.

How can I encrypt my phone calls for free?

Install Signal or WhatsApp on both phones and call through the app. On Apple devices, FaceTime Audio is also end-to-end encrypted. All three are free.

Is FaceTime end-to-end encrypted?

Yes. Apple says FaceTime audio and video calls are end-to-end encrypted and that Apple can’t decrypt them. Both people need to use Apple devices.

Are WhatsApp calls encrypted?

Yes. WhatsApp personal calls are end-to-end encrypted by default using the Signal Protocol.

Can the police or my carrier listen to encrypted app calls?

The carrier can see that you’re using data, but it can’t hear an end-to-end encrypted call made through an app like Signal. However, anyone with access to an unlocked phone at either end could still see or hear what’s on the device.

Does Google Messages encrypt phone calls?

No. Google Messages encrypts RCS text chats when everyone uses Google Messages with RCS turned on. Calls from the Phone app are regular carrier calls and aren’t end-to-end encrypted.

Is Skype still available for encrypted calls?

No. Microsoft retired Skype in May 2025 and moved users to Microsoft Teams.

Sources

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George Mutune

I am a cyber security professional with a passion for delivering proactive strategies for day to day operational challenges. I am excited to be working with leading cyber security teams and professionals on projects that involve machine learning & AI solutions to solve the cyberspace menace and cut through inefficiency that plague today's business environments.