WhatsApp: “Your security number has changed” – what’s going on?

If you open a chat in WhatsApp, it can happen that the message “Your security number has changed” stands. The message has been appearing more and more among users since Thursday evening for no apparent reason. What does that mean?

In many cases, this notification is of minor importance, but sometimes it can be a serious security issue. GIGA explains what you should pay attention to when reporting the changed security number.

What is the “security number” in WhatsApp?

Update from November 5th, 2021: Many users are currently unsettled because the message about the changed security number suddenly appeared in all chats without changing the number or smartphone or reinstalling WhatsApp. WhatsApp has not yet provided any information about why the message appears with so many users. There is no known hack or other security vulnerability. According to rumors, it could be a bug related to the playout of the multi-device function. GIGA keeps you up to date. There are currently no signs of a hack or the like.

The background to the security number is WhatsApp’s end-to-end encryption. That means news can read only on the devices of the sender and recipient and not be intercepted. Every chat on every device with WhatsApp installed is a unique security key assigned. This is a QR code or a 60-digit sequence of digits. The numbers can be matched between the chat participants to ensure that the encryption works. If the above message appears in a WhatsApp chat, it can have various causes:

The chat participant has reinstalled WhatsApp on their device. The contact installed WhatsApp on a new device and took their old account with them. A new phone number has been linked to this WhatsApp contact.

To be on the safe side, you can ask the relevant contact whether one of the reasons for a changed security number is present.

WhatsApp: “Your security number has changed” – what does that mean?

You should prefer the question but not via WhatsApp, but ask another messenger or in person. The security number also changes if you have a WhatsApp account taken over by strangers and was set up, for example, on a third-party device. If you write to the relevant contact via WhatsApp, you will not know who is actually reading your message.

The most important data protection settings for WhatsApp in the video:

If the other person has not done anything to their WhatsApp account or smartphone, their account may have been hacked. In this you should make sure not to pass on any sensitive, private information via chat. Your contact should contact WhatsApp support directly to get their account back.

If the security of the chat is not so important to you and you no longer want to be disturbed by the mentioned message, you can deactivate it as follows:

Opens the settings from WhatsApp. Select the section “Account” the end. Here you will find the area “safety“. Set whether you continue Security notifications want to receive or not if the keys are changed.