Signal, the state-of-the-art open source encryption app for mobile, came to the desktop late last year, but only through an invitation system. The desktop app (which is still in beta) is now available for anyone who wants to download it from the Chrome web store.
Whatsapp and its billion users recently started enjoying the same kind of encryption that Signal uses: end-to-end, with messages encrypted between users and without allowing the company hosting the servers to look inside that encryption (especially if the users verify themselves with security codes).
To some degree, users still have to trust that Whatsapp won’t change or backdoor that encryption surreptitiously. For those who would rather not trust a closed-source application from Facebook, and would rather trust a group of developers that have a strong track record of speaking out against mass surveillance and developing apps with strong cryptography, Signal is still the better choice. It doesn’t have nearly as large of a user base as Whatsapp, but it has been growing steadily lately.
Open Whisper Systems launched a private beta version of its Signal Desktop app for Chrome in December last year. It initially required an invitation, which may have actually hurt its adoption at the time.
However, the private beta also allowed the team behind it to get valuable feedback from people who really wanted to use the app. The non-profit organization said the desktop app has been refined since it launched to improve its look and feel.
Users can chat either one-on-one or in a group, knowing that their messages are always end-to-end encrypted by default. They can also send attachments with photos or videos. However, unlike the mobile apps, it doesn’t yet have a calling ability. Video is also still lacking from both the mobile and the desktop applications, which means it won’t be a full replacement for Skype or Hangouts until that changes.
Voice and video calling is likely harder to do securely in a browser, which may be why Open Whisper Systems hasn’t implemented them yet, and why the group may take its time to get them right. As an open source non-profit group, its priorities aren’t necessarily new features that it can promote to users, but the absolute security of the features that the group does decide to implement.
Lucian Armasu is a Contributing Writer for Tom's Hardware. You can follow him at @lucian_armasu.