Signal lets users report and block spam messages

Signal now gives users the option to report and block spam messages. With this, the company wants to develop a system that makes it easier to detect such messages. Signal promises that all user activity will remain encrypted and anonymous.

When a user presses “Report and Block Spam” via the Signal app, only the potential spammer’s phone number and an anonymous message ID are sent to the server, the company said. This is different from, for example, chat apps such as WhatsApp, where the reported content is sent unencrypted to moderators. If accounts are reported more often, the spammer will not be able to send messages until they complete a Captcha-like challenge.

Signal says it will build a system based on that information to better combat spam. That has to run server side, and not locally on the client. While Signal is largely open source, the company isn’t going to share the implementation of that code. As a result, Signal says it stays one step ahead of spam accounts, while at the same time, according to the company, it does not affect the ‘fundamentals of the security model’ of the chat app.

Signal has added a number of other features to counter scammers. For example, people who send a message to someone for the first time must first be accepted by the recipient before the photo and name of the latter become visible to the sender. The photo of the person who sends the first message is also initially not visible to the recipient. It only becomes visible when the faded photo is clicked. Also, users cannot open links sent in the first message from an unknown person until the sender is accepted.