The popular messaging application WhatsApp has recently alienated many users with its new terms of service and privacy policy. It's a situation that once again illustrates that when you put yourself in the hands of a proprietary service, you put yourself at the mercy of the operator. If you are dissatisfied with a change, either you grudgingly continue using the service, or you move to a different application with similar features.

In the case of WhatsApp, there are quite a few alternatives, and many were suddenly overrun with WhatsApp users looking for another option. This article looks at the different categories of messaging services, and then delves into one particular option – using peer-to-peer messaging apps based on the Tox protocol.

Open Source Clients

Signal [1], Threema [2], and Telegram [3] are widely regarded as good alternatives to WhatsApp, partly on the grounds that they operate more freely and openly than the Facebook service. This typically means releasing the app source code under open source licenses and disclosing the underlying protocol so that other app developers can develop alternative clients (see Table 1).

However, discussions of social media alternatives often leave out one very important component: the server. All providers keep a watchful eye on the server and therefore on the data. Telegram and Threema do not disclose the source code for the server. Signal does provide the source code for the server under a free license, so users could theoretically build their own Signal servers. However, the software is designed in such a way that the different instances cannot talk to each other. If the same principle applied to email, then users of one service (such as Yahoo Mail) would not be able to send messages to those of another service (e.g., Gmail).

Federated Systems

True freedom exists only if the service discloses the source code of the server and client(s) and the underlying protocols. In addition, the network systems must operate in a federated manner, that is, in a distributed manner (federation). However, this kind of freedom goes against the business interests of commercial providers. Therefore, none of the major providers offer this level of freedom. What remains are services and programs such as Dino [4] and Quicksy [5], which are based on the classic XMPP (formerly Jabber) [6], and applications such as Element, which is based on the Matrix [7] open communications protocol.

Peer-to-Peer Networks

Instant messengers can do without any kind of a central authority. They work in a similar way to file-sharing programs like eDonkey or BitTorrent. Messages or voice and video chats travel directly from computer to computer (peer-to-peer) over the network. The contacts are organized with the help of a distributed hash table (DHT). End-to-end encryption ensures that privacy is maintained and that only the sender and the recipient can read the messages.

In this category, the selection of programs is thinned out even further. The last tools standing are Briar [8], Jami [9], and Tox [10]. Briar is available exclusively for Android-based smartphones and tablets. I have already covered Jami in detail in a previous issue [11], so now it is time for a closer look at Tox.