"The Guardian's story on an alleged 'backdoor' in WhatsApp is false. WhatsApp does not give governments a 'backdoor' into its systems. WhatsApp would fight any government request to create a backdoor," said Brian Acton, Co-founder WhatsApp, in a Reddit post.
WhatsApp has published a technical white paper explaining its implementation of end-to-end encryption.
The security issue was detected by Tobias Boelter, a cryptography and security researcher.
"If WhatsApp is asked by a government agency to disclose its messaging records, it can effectively grant access due to the change in keys," The Guardian quoted Boelter as saying.
"The fact that WhatsApp handles key changes is not a 'backdoor', it is how cryptography works. Any attempt to intercept messages in transmit by the server is detectable by the sender, just like with signal, PGP, or any other end-to-end encrypted communication system," said Moxie Marlinspike, who designed WhatsApp's encryption, in a blog.