In a blog post Thursday, Moxie Marlinspike, cryptology expert and founder of OWS, said that this will allow “Private messaging, now with all ten fingers.” He also noted, “Signal Desktop is a Chrome app which links with your phone, so all incoming and outgoing messages are displayed consistently on all your devices. Your contacts don’t have to guess where to message you, and when you switch devices the conversation you started will already be there.”
Signal uses a data connection to send encrypted SMS messages, so SMS traffic will count against your carrier data cap. But users also get carrier independence, as long as their phone has a data plan, since SMS messages sent using Signal are no longer linked to a carrier’s network.
Signal Desktop is only available for Android users and will only work for text-based messaging and not voice for now. Signal for Android currently supports messaging, voice calls, and transmission of pictures and video between apps on phones.
OWS said a desktop version that syncs with iOS devices is coming, but gives no timeframe for it and suggests following the nonprofit software group on Twitter (@whispersystems) to see when it will be available. Signal for iOS was first released in 2014, and upgraded to version 2.0 this March.
In addition to Snowden, others privacy advocates have expressed their appreciation of Signal, which is open source (meaning the source can be examined for backdoors) and free (although donations are accepted).
Well-known security technologist Bruce Schneier also endorsed OWS products. He is rather effusive about group’s offerings saying, “I am regularly impressed with the thought and care put into both the security and the usability of this app. It’s my first choice for an encrypted conversation,” on the OWS site.