Privacy Blog

"Friends don’t let friends get spied on.' – Richard Stallman, President of the Free Software Foundation and longtime advocate of privacy in technology.

Silent Circle Provides Encrypted Voice Calls from your Cell Phone

When a Silent Circle subscriber makes a phone call, sends a text or video chats with another Silent Circle member, that transmission is secured and encrypted end-to-end from their iOS, Android or Windows PC device and is transmitted via Silent Circle’s crystal-clear, secure network.

Silent Circle provides an encrypted communications service with easy-to-use tools available to all who appreciate a little control over who has access to their conversations. The service is billed as “50 percent less expensive” and, of course, appeals to the security-conscious. Indeed, Silent Circle has become a trusted solution for mobile privacy serving individuals, businesses, and governments in over 130 countries. The company is headquartered in Switzerland with employees in eight countries. Being based in Switzerland means the company is bound by Swiss privacy laws and is less subject to policies and legal demands of other, less-privacy-minded governments.

Silent Phone is a secure mobile voice and video calling solution. It is an easy-to-use app that provides you with HD-quality calling over 3G/4G and WiFi networks using the ZRTP encryption protocol invented by Silent Circle’s co-founder Phil Zimmermann. The ZRTP protocol detects when the call starts, initiates a cryptographic key agreement between the two callers, and then proceeds to encrypt and decrypt the voice and data packets on the fly. Key negotiations are purely peer-to-peer through the media stream. Keys are destroyed at the end of each call.

The secure communications software is available for iPhone and for Android phones. The company also sells a $629 “Blackphone” that is a high-end an Android phone with the Silent Circle software already installed. The Blackphone also has numerous modifications to keep all information stored within the phone secure. Even if your Blackphone is seized by a law enforcement agency or at Customs when entering a country or is stolen at any time, nobody else can see the information stored within your Blackphone.

Silent Circle provides the following on all Android phones, iPhones, and Blackphones:

  • International Encrypted Calling Unlimited member to member calling AND … you can even use Silent Phone to make encrypted calls Outside the Circle.
  • Escape From Roaming Charges – Save big on your monthly bills with Out-Circle Calling to more countries than any other service. You’re still encrypted from wherever you are to Silent Circle’s proprietary network.
  • Ultimate Flexibility – Choose your new secure number so non-subscribers can call you directly anywhere. Make calls to 120 destinations around the world or down the street.
  • HD Voice & VideoSecure Video Chat
  • Conference Calls
  • Silent (encrypted) text messages to other Silent Circle members

Out Circle Calling begins at $12.95 for 100 minutes per month as well as unlimited member-to-member voice calls and texts. If you need more minutes you can sign up for 250 monthly minutes at a cost of $19.95, and $39.95 per month for 1,000 minutes. The service will be available in 79 countries. Pricing details may be found at

In addition, the company also offers Silent Phone For Desktop, a similar service designed for desktop and laptop Windows computers.

Whether you are across the globe or down the street, the Silent Circle network offers industry leading encrypted communication and secure access with no contract. The service is low-cost, so low that it is cheaper to call someone in a foreign country via Silent Circle’s secure network than it calling via the normal cell phone network. In fact, Silent Circle subscribers can also make non-secure calls to both cell phone and landline phones in almost all other countries at similar, low-cost rates.

Silent Circle also offers servies for corporations with one bill for all phones and a management console to assign user controls.

You can learn more at

Categories: Cell Phones

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