There are sharing and instant messaging software that are used all over the world, but if you want to be sure that the connection is secure, then you can use RetroShare
What is Retroshare
Retroshare is software that allows you to securely chat and share files with friends using a P2P and OpenSSL system to encrypt all communications.
You do not need to register or fill out custom forms with all kinds of data. No one is interested in your data, RetroShare
for Linux offers privacy even in front of Internet service companies (ISPs). No one will be able to see the files you are sharing.
Sharing services offered
To access RetroShare
for Linux services, you only need to create a user account with your credentials, username, and password. Retroshare also has the option of instant messaging and offers the possibility to connected users to discuss in private or in a group. You can also share files with other users on your local network.
The level of encryption may vary depending on your needs.
To avoid forms of electronic hacking during sending, you can encrypt the shared data. Use encrypted communication and the shared information remains with you and your friends.
for Linux creates encrypted connections with your friends and is totally decentralized, no one can spy on you, it is also completely open-source and free and there are no costs, no advertising and no terms of service.Documentation / Demo
* Chat : Send text and images. Discuss with various people in decentralized chat rooms (like IRC). Express your emotions with the rich smiley set. Use distant chat to securely chat with friends-of-friends.
* Mail : Send encrypted messages to other members of the network. Retroshare securely stores messages on friends nodes to deliver messages while youre offline.
* File sharing : Share files with your friends or with the whole network. Use the search to find files. Retroshare uses swarming similar to BitTorrent, to accelerate transfers. This makes it possible to share large files. Your privacy and anonymity is guaranteed beyond direct friends with anonymous tunnels.
* Forums : You can read and write forum posts offline. This is perfect while youre on the go. When you have an Internet connection, Retroshare will automatically sync forums with your friends. Decentralized forums are censorship resistant by design.
* Links : Share your favorite links. See which links others like. Vote and discuss them using the built-in commenting system.
* Channels : Channels allow you to publish your files. You may subscribe to channels and automatically download the latest files; comment on files and spread them to your friends.
* Protect your IP with Tor/I2P : Retroshare can optionally be used over the Tor and I2P networks. Doing so, even friend nodes cannot see your IP, which allows to safely and anonymously connect to unknown people.