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Signal – iPhone Encrypted Messenger and Voice

Signal – iPhone Encrypted Messenger and Voice


Signal is an end-to-end encryption messaging and voice app for the iPhone

Signal is a messaging and secure voice app for the iPhone, created by Open Whisper Systems. Signal is open source which means the code is available for security auditors, developers  and anyone to look at and verify it is doing what it is suppose to do and without “backdoors“. Signal is also available for Android and announced in December 2015, Signal will soon be available for desktop computers for cross platform secure voice and text communications. So your friends & family who use android, will still be able to communicate with you securely.

Signal provides end-to-end encryption for the phone calls you receive or place so nobody can listen in. The app uses your normal phone number to make and receive calls, so the user doesn’t need a different identifier or number, they just need the Signal app.

An extra layer of security is provided end-to-end so it looks like you are calling from your phone just like you are used to.Use your iPhone to scan the QR code to download the Signal app. The app is free and there are no in-app purchases.

Signal uses  3G/4G or Wi-Fi data, so there is no need for a monthly subscription or pre-paid plan for voice minutes.

As soon as you install the app, Signal asks you to enable access to the microphone, contacts, and push notifications. These are pretty basic permissions for an app to do what Signal does. You can proceed to choose the country code and enter your phone number. The app interface is basic and mostly designed in black and white. There are five menus on the bottom of the screen: Call Log, Favorites, Inbox, Contacts, and the dialer. You will only be able to make end-to-end encrypted phone calls if both parties use Signal.

Open Whisper Systems has created a reliable way for the user to place a phone call or send a private text message. It took nearly a year to code this app for the iPhone which was originally created for Android devices.

Open Whisper Systems pride themselves in creating an app that doesn’t need a password or any other complicated systems to preserve your privacy. When someone calls you, you will see the contact information like you would on your regular “Phone” app from iOS. Signal uses the well-tested ZRTP protocol, for secure voice communication. ZRTP was developed by Phil Zimmermann, the creator of PGP.

There’s no need to keep the app open all day. You will know when someone calls you via push notifications, just like Skype does.

Signal should take the place of your default messenger. If someone does not have Signal, messages will still be sent as normal in clear text. Some highlights include:

  • Easy to use – Send high-quality group, text, picture, and video messages, all without SMS and MMS fees, completelysignal-messenger encrypted.
  • Speak Freely – Make crystal-clear phone calls to people who live across town, or across the ocean, with no long-distance charges.
  • Nothing to forget – Signal uses your existing phone number and address book. There are no separate logins, usernames, passwords, or PINs to manage or lose.
  • You are in control – Even Open Whisper Systems or their servers cannot hear your conversations or see your messages, and no one else can either. No exceptions. You can even tap and hold on a contact’s name to see advanced identity verification options. Everything in Signal is always end-to-end encrypted and painstakingly engineered in order to keep your communication safe.
  • Fast – Signal is optimized for speed without compromise. Our state-of-the-art Axolotl protocol is unmatched in its performance, strength, and reliability.
  • Remain Connected – Push notifications let you know when new messages have arrived, and they’ll be waiting for you even if your battery dies or you temporarily lose service.
  • Get Organized – Unique archive functionality makes it easy to keep track of the conversations that matter to you right now.signal-contacts
  • Pay Nothing – Signal is supported by a team of dedicated developers, community donations, and grants. There are no advertisements, and it doesn’t cost anything to use.
  • View Source – All of the code is free, open, and available on GitHub.
  • Join Movements – Technology developed by Open Whisper Systems is trusted and used by millions of people around the world every day.
  • Include Everyone – Signal is fully compatible with Android users if they have Signal too.

Download Signal    Sign up for Signal Desktop

Signal News and Reading:

Copperhead announces a Fork of Signal for their Android OS

Signal uses domain fronting to bypass censhorship – Dec 23, 2016

Feds tried to inflict year-long gag over data request from Signal chat app – 5 Oct, 2016

Signal Threat Modeling

Create an anonymous Signal phone number w/ Android




  1. Signal is certainly a good choice. I still prefer Threema, though. In terms of being updated, Signal lags a bit (while Threema is updated regularly). And Threema also sports some unique features (e.g., you can create polls). Anyway, since both offer end-to-end encryption, either is fine.