Google Drive and Whatsapp I have lost my phone number and there is no way I can get back the same number from the operator.
I want to restore my whatsapp chats which were safely backed up on google drive.
I need those chats as its the matter of my career. Can anyone help to decrypt those backups from the google drive. 
I can't arrange the same phone number to receive backup on my android device because the number has been allotted to someone else.
Whatsapp Backups are stored in your google Drive account, but you cannot download/read those files as they are encrypted. From google Drive, you can only delete them (as shown in picture) or remove them from GDrive account.



Even if you're logged with the Google account where the backup is stored, you cannot restore it if you are not using the same phone number that was used to create the backup. (more info here)

I think the best way to find a solution is contact the Whatsapp support directly. There is no way to download your backup from gdrive right now.