Silentel is a scalable suite for secure communications, it can be used in mobile devices and desktop computers. The program provides a software based solution to protect your voice calls, secure chat, file transfer and text messages from wire tapping
Data is secured with end to end encryption, there is a central server redirecting traffic to the intended receiver but everything is encrypted on the client site, it is not possible for a third party to access plain text on the server, there isn’t any text to find, only metadata would be visible to a rogue observer, like timestamps and who is communicating with who. Metadata information that is hidden from your mobile network operator, Silentel protects you from well known spy agencies backdoors on mobile networks.
Data transmission is secured with public key encryption managed by Silentel in the hosted plan (enterprises can have their own infrastructure), voice calls are authenticated with the RSA algorithm and encrypted with AES256-bit one time keys. Phone calls employ a unique key that is never reused and destroyed as soon as somebody hangs up, this guarantees that if one of the keys falls in the wrong hands it won’t be of use to decrypt more than a single call. SMS text messages will also be encrypted and they can be set with an expiration date after which the message is wiped.
This is a very simple to use secure voice calling software, once you have it installed you should add contacts of other people who are also Silentel users, when you want to place an encrypted call or establish a secure chat select the person from your contact list and choose “Make a call” from the menu, Silentel will automatically create the ephemeral encryption keys, and once the call has finished it will delete those keys. Text messages, files and contacts are not kept in your smartphone, if you lose the phone you will not have to worry about anybody finding them
This product can be used by individuals, corporations and governments, Silentel is included in NATO Information Assurance Products Catalogue and it has a NATO confidential certification as well as a National Security Authority and Ministry of Defence certificates of the Slovak Republic.
This product is not cheap but the kind of customer they are targeting, government employees and CEOs will risk much more by placing insecure calls and sending plain text messages containing trade secrets or compromising details. Furthermore, if you are on Wifi, Silentel calls will be free and you won’t have to pay any charges for placing them.
Silentel security model is satisfying and the security certificates they hold are reassuring, not being a USA company is of great advantage to avoid invasive NSA spying orders, that is perhaps one of the main reasons to choose them over similar services like Silent Circle. I did not like that there is no Linux or Mac version of their software but on the mobile front they cover iPhone, Windows and Android devices.
Just remember that the receiver will have to be using the same software to be able to communicate securely, that is perhaps the hardest part, to convince colleagues of the need to secure against spying but once you achieve that, the learning curve for Silentel is very very low, if you know how to use a smartphone, you will know how to use Silentel out of the box.