Phil Zimmermann’s Silent Circle builds a secure, seductive fortress around your smartphone

October 10, 2012

(Credit: Silent Circle)

The cryptography legend Phil Zimmermann is teaming up with two ex-Navy SEALs to offer encrypted phone calls, video conferencing, and text messages with no learning curve whatsoever.

The target market? Businesspeople and government employees traveling abroad, Fast Company reports.

Silent Circle, which launches on October 15, is a secure communications product for Android and iOS that works on a paid subscription model. Users will have access to encrypted phone calls, emails, VoIP videoconferencing, SMS text messages, and MMS multimedia messages.

Security varies depending on whether communications are made to another user on Silent Circle’s closed network, or to an outside user. Text and multimedia messages are wiped from a phone’s registry after a pre-determined amount of time, and communications within the network are allegedly completely secure.

Subscribers will pay $20 a month, which includes unlimited subscriber-to-subscriber conversations, encrypted video conferencing, encrypted text messaging, encrypted email, and storage. Text messages will only be encrypted when sent to other Silent Circle subscribers. Outdialing to public telephone networks (in which Silent Circle users’ ends are secure but the other end is insecure) will be optional with an additional fee. For an additional $39 a month, Silent Circle is offering 3000 calling minutes for the United States, Canada, and Puerto Rico.

The startup’s secret sauce is the dead-simple interface of their secure communications products. Both the iOS and Android versions are skinned to look like their respective systems’ dialing/text message systems. Video conferencing strongly resembles Skype. Subscribers will have ten-digit identification numbers which resemble phone numbers (and which, Silent Circle claims, will become phone numbers at a later date).

According to Zimmermann and Janke, all products use device-to-device encryption. PGP RSA public key encryption will be used for emails, ZRTP for video and voice, and a custom instant message protocol called SCimp, which, Silent Circle says, is currently in the peer review process, will be open sourced with white papers to follow.

The email product will be a Sparrow-like app with 100% peer-to-peer encryption. Text messages will be encrypted device-to-device with a special option to set a timer that will erase them from the registry.

Silent Circle stresses that their product offers secure communications within the networks and only uses Canadian servers that are outside of U.S. government control. Canada has far more stringent data privacy regulations than either the United Stations or the European Union, meaning that users’ encrypted communications are less likely to be intercepted by American authorities.