WhatsApp is joining Google and Apple in offering better security for their software and end-to-end encryption for all messages sent by Android users.
WhatsApp also said that it will not be able to help law enforcement decrypt the messages, essentially putting its users' privacy at the top of its priority list.
"WhatsApp is integrating TextSecure into the most popular messaging app in the world, where people exchange billions of messages a day," said well-known cryptography expert and Open Whisper System's creator Moxie Marlinspike. "I do think this is the largest deployment of end-to-end encryption ever."
Currently the encryption only applies to messages sent between Android phones, with the latest version of the Android app automatically encrypting messages without the need for users to enable the feature. The feature does not apply to group messages or media messages.
WhatsApp co-founder Jan Koum, who grew up in Ukraine when it was still a part of the Soviet Union, has long been a proponent of privacy.
A number of other messaging services use end-to-end encryption, but they are not all as secure as WhatsApp. Apple's iMessage uses encryption, but that data is stored on Apple's servers, meaning law enforcement can request the data from Apple if it needs to.
TextSecure has been encrypting messages sent from WhatsApp between Android devices for a week. Starting now, WhatsApp messages will travel to a recipient's device before being encrypted. Before, messages were only encrypted when they reached WhatsApp's servers, after which they were sent, decrypted, to the recipient's device.
The change is invisible to users, and will not affect speed of messages sent or received. The average user will not notice a difference, however those more interested in tech will likely appreciate the move by WhatsApp.
While the new security features are only available on Android devices right now, the company plans on bringing the improved encryption to iOS users in the near future. Encryption of WhatsApp messages has reportedly been in the works for six months.
"WhatsApp deserves enormous praise for devoting considerable time and effort to this project," continued Open Whisper Systems. "Even though we're still at the beginning of the rollout, we believe this already represents the largest deployment of end-to-end encrypted communication in history."
WhatsApp was acquired by Facebook earlier this year, but the company has remained insistent that it operates independently. In this move, the company has stressed its independence from Facebook and that it is very committed to privacy.