How to change your Whatsapp security code. Whatsapp encrypts chat messages so that no one can have backdoor access to them. It does it through an encryption key which is kept hidden.
For users, this encryption key appears as a security code which can be used to verify that chats are indeed encrypted. Encryption is enabled for all users and there is no deactivate button. You may have noticed that sometimes you get a message in a chat thread telling you that a contact's security code has changed and wondering how you can change your Whatsapp security code.
Change the Whatsapp security code
There is no way to manually change the Whatsapp security code. There are two cases in which Whatsapp will automatically change the security code for you; when you change your phone number or phone or when you delete and reinstall Whatsapp.
Reinstalling Whatsapp is the easy way to change your Whatsapp security code, however, you may lose some of the chat threads. Uninstall it as you would any other app on your phone, then install it again from your respective app store. It is highly recommended that you do the first to uninstall Whatsapp as not all messages may be saved and restored when you install the app again.
Temporarily use another phone
This requires temporary access to another phone. You will only need it for as long as it takes to download and set up Whatsapp.
Download Whatsapp and enter the same phone number you use with it. Do not insert a SIM into the phone. Whatsapp verifies that the phone belongs to you by sending a verification code. When you get the code on your regular phone, enter it on the second temporary device you have. This will activate the security code to be changed. You can then delete the app from the second phone.
Whatsapp security code alert
All your contacts will be notified of the change in your security code. Likewise, you also get a warning within a chat thread when one of your contact's security codes is changed. If you wish, you can disable these alerts. For disable the security code warning you get for your contacts, go to the Settings tab on Whatsapp.
Tap your account at the top. On the Accounts screen, tap Safety. On the Security screen, turn off the option "Show security notifications".
This will prevent notifications from appearing on the device, however your contacts will still know when your security code is changed.