DS Talk - direct secure calls for PC

Do you respect freedom and privacy during phone calls? In this case this application for making free secure voice calls in a trusted private group will be definitely interesting for you. Communicate with friends and relatives all over the world via the Internet wherever you are. No Internet? No problems! Enable WiFi hotspot on one device, connect to it from other devices and communicate anywhere as if using a walkie-talkie!

Usage of this program is very simple:
1. Choose your own user name.
2. Add user names of people with whom you wish to communicate into the application's contacts list by using "+" button. On-line contacts available for calling are being marked by the green mark to the left of the user name.
3. For creating of the private group you need to set the group password which should be the same for all members of the group. In this case only people with the same password will be able to communicate.

A quick test: Connect two devices to the same Wi-Fi network. On the "Settings" page of the first device set the user name to Alice and set the group password to 12345, and on the "Contacts" page add the user Bob to the contacts of the program. On the second device, similarly set the user name to Bob and set the group password to 12345, add the user Alice to the contacts of the program. Please note: the user name on one device must exactly match the name added to contacts on the other device (the case of characters is important, all entered characters are important, including spaces, punctuation marks, etc.). The group password must be the same on both devices.

And now about how freedom, independence and privacy of your conversations are ensured:

True freedom and independence. It's a completely decentralized communication system. It does not depend on any Internet servers and services which could stop working due to crashes, hackers activities, sanctions and for other reasons. A direct connection (peer-to-peer, P2P) is established between two devices during a call. Calls with HD voice quality are possible as in high-speed mobile 3G/4G/LTE or Wi-Fi networks and also through a slow 2G GPRS/EDGE connection. This application works even in a pure AOSP without GAPPS (for true adherents of freedom and independence).

Protection of your privacy. Absolutely no information about you is required! Neither the phone number, nor e-mail, nor IMEI, nor something else is necessary. You just choose your user name (nickname) which can be changed at any time. This application does not store the call history and any activity logs. Your location information is not required. Therefore, only a minimum of permissions is required for this application, and it is quite sufficient for voice calls! All calls are encrypted using the AES algorithm with a 256-bit key, and a new random encryption key is generated for each communication session. A group password is used to access a private group and to securely exchange encryption keys between members of this private group, therefore choose a complex password and change it periodically if necessary. Each network packet of the communication session is completely encrypted and absolutely unique, which makes useless any network traffic analysis systems usually used to detect, wiretap and block IP telephony protocols such as SIP, IAX, RTP, ZRTP and SRTP.