Android smartphone owners who care about privacy in messaging have a new app available to them that will allow them to communicate securely with iPhone users.
Open Whisper Systems, the company behind Signal, has finally released a version of the private messaging app for Android. As former CIA hand Edward Snowden attested yesterday, he regularly uses Signal, which until Monday was only available for the iPhone.
Android users keen on private messaging and encrypted calling will probably be familiar with Open Whisper Systems, which had previously released TextSecure and RedPhone for Android, offering the respective functionality across two separate apps. They've now been unified into one Signal app, matching up with the iPhone version.
TextSecure users should receive an update that brings the combined functionality in the next few days, Open Whisper Systems' founder Moxie Marlinspike said in a blog post on Monday.
When Signal 2.0 was released for iPhone earlier this year, it supported encrypted messaging with TextSecure on Android, however encrypted calls were restricted to devices, namely iPhones, with Signal installed.
Meanwhile, Android users with RedPhone installed will be prompted to install Signal instead.
"As always, Signal uses your existing phone number and address book. There are no separate logins, usernames, passwords, or PINs to manage or lose," noted Marlinspike.
"We cannot hear your conversations or see your messages, and no one else can either. Everything in Signal is always end-to-end encrypted, and painstakingly engineered in order to keep your communication safe."
Open Whisper Systems earlier this year phased out encrypted SMS in TextSecure, partly in response to the Signal app for iPhone since it wasn't possible to send encrypted SMS to an iPhone.
Another reason is that SMS, regardless of its content being encrypted, leaked metadata to mobile operators in countries where governments might become aware of people who are using TextSecure.
There are dozens of secure messaging apps that claim to offer private messaging. But only a handful, including Signal and Text Secure, have passed all marks in the Electronic Frontier Foundation's secure messaging scorecard.
TextSecure only had up to five million installs from Google Play. However, WhatsApp has integrated the TextSecure protocol in the app to provide end-to-end encryption as did Cyanogen before that.