Well-known instant messengers include WhatsApp, Threema, Telegram, iMessage, Signal and Facebook Messenger. Closed systems like these allow people who use the same messenger system to chat. Closed messengers mostly use similar encryption methods, with not all providers using full end-to-end encryption for all of their functions.

There are also open systems that are not specific to a particular provider and that are based, for example, on the XMPP or Matrix communication protocols. The main difference between these and the closed systems mentioned above is that you can choose your preferred provider from the large number of options but still chat across different messengers with anyone that uses the same protocol. In addition, no telephone number is required for these chat systems. However, with these types of free messengers, users must check for themselves whether their provider actually supports the desired encryption technology.

The messages that can be sent via messengers consist of the text of the message, any file attachments, such as photos, and what is referred to as metadata. The metadata includes the identifier of the sender, often in the form of their telephone number, the identifier of the intended recipient, the date and the time. Other information can also be included. This sort of data is not just used to correctly direct the message but can also be used to analyse preferences and for similar purposes. This allows profiles to be created that can be used for the purposes of personalised advertising.

The General Terms and Conditions (GTCs) or the Privacy Policy lay out what the provider does with its customers' data. These sorts of documents are generally long and complicated. In addition, in Germany, according to statements made by Peter Schaar, the (now former) Federal Commissioner for Data Protection and Freedom of Information, it has not been fully clarified at what age children are even legally competent to consent to data processing (Peter Schaar in: Chatten ohne Risiko? [Risk-free chatting?] (2009), available (in German) at: www.chatten-ohne-risiko.net)

What to bear in mind when using messengers

1. Keep your messenger app up-to-date by installing updates immediately.
2. Consider how reliable the provider is. Also bear in mind what country the provider is based in. Privacy laws vary from country to country.
3. Messengers are constantly tested and retested for encryption and compliance with data protection. Take the results of such tests into account when choosing a service.
4. Bear in mind that messengers on mobile devices typically request extensive authorisations and therefore have significant access to the resources of your device, such as to your complete contact list. Try to restrict these rights wherever possible.
5. To prevent any third parties from accessing the content of your communications, the messages should be exchanged in encrypted form. We have explained what this means and how it works here.
6. Block contacts if you are unsure who the person is or if someone is hassling you. Report any insulting behaviour, sexual harassment, coercion, blackmail attempts or threats to the police.
7. Read the GTCs and the Privacy Policy, focussing particularly on what happens to your data and information. Is the data sold, stored or encrypted? Are you willing to accept the contents of these documents?
8. There are messengers that are connected to social networks. Such connections are dubious from a privacy perspective. You can quickly lose sight of who you have authorised to access what content.
9. Support your children. Child protection laws cannot take the place of parental responsibility. Take an interest in your children's online activities, what they are doing, what they are interested in, and who they are talking to.

Using videocalling securely

Digital services can be helpful to prevent loneliness these days. One practical and simple solution is videocalling. From a technical point of view, all you need is a smartphone, tablet or computer. Many of these devices have microphones and cameras built in. If in doubt, those who have an older PC may need to upgrade and order a microphone or camera. One important requirement for videocalling is that your device is connected to the internet. Finally you need an application that allows you to make video calls. Agree with your family what service provider you will all install, because the different services are not compatible with each other.

If you have an internet tariff for your smartphone, or your device is connected to your home WLAN, the methods for making video calls listed here are free of charge. There is one exception: Do not call any landlines using any of the applications. This may incur charges.

What applications are there?

There is a huge range for anyone interested. The best-known services are WhatsApp, Zoom, Signal, Webex, Teams, Skype, Wire, Facetime and Google Duo. These applications all enable video calling and only vary in the detail of how they do it. Some have better image quality, others allow entire groups to videocall, and others again require you to create a user account.

This, however, raises the fundamental question of whether you want to use the service on a computer, laptop, smartphone or tablet. For example, Google Duo, Wire, Zoom, Signal, Webex, Teams and Skype are available on both computers and on mobile devices, whilst WhatsApp only works on smartphones. One exception is Facetime. This application works on Apple mobiles, tablets and computers, but not on devices from other manufacturers. For further information about how you can install various applications or apps, please see below.

Our tip: Ask your family which applications they already have available. For example, if everyone owns an iPhone, then Facetime comes preinstalled on the device. WhatsApp and Zoom or Signal, on the other hand, are widely used across different devices. At the same time, all of the services mentioned provide the functionality for group chats and therefore video conversations between multiple people.

How can you make phone calls securely?

Applications for videocalling are subject to the same risks as most other apps or programs on the internet. However, by following just a few tips you can configure these applications to be as secure as possible:

• Only download applications and programs from reputable sources, e.g. the Appstore from Apple or the Playstore on Android devices.
• If you have to create a user account, use secure passwords following the recommendations of the BSI. Do not use the same password more than once. Solutions known as password managers (additional applications) or password books (traditional notebooks) are recommended to help you manage your passwords.
• Use video calling on your home WLAN or LAN wherever possible. Secure your network with a particularly strong password.
• Only accept calls from contacts that you know, and ideally that you are expecting a call from.
• Always keep your videocalling software and the operating system up-to-date by installing updates.

Additional tips and guides

The Digital Compass website provides comprehensive brochures on Skype and WhatsApp (in German, see below). This video explains how you can set up the program Skype on an iPad. There is also comprehensive assistance available. The Digital Compass is a joint project between the German National Association of Senior Citizens' Organisations (Bundesarbeitsgemeinschaft der Seniorenorganisationen; BAGSO) and Germany Safely Online (Deutschland sicher im Netz; DsiN).