The gold standard of encrypted messaging
Open source, industry-leading encryption+Supports disappearing messages too-Rather sparse interface
Signal is widely regarded as the gold standard of encrypted messaging apps, not least because its encryption engine is open source and available for anyone to inspect. That doesn’t make it any easier to hack, but it does mean there are a lot more pairs of eyes looking at the robustness of the encryption methods.
Besides the industry-leading encryption on offer here, the app itself is fairly plain and basic in terms of visuals and appearance. It does support group chats though, as well as the sending of files and photos in addition to text, so you’re going to be pretty well covered no matter what your needs.
Signal can replace the default SMS app if you want it to, but basic SMS texts aren’t encrypted – you and the person you’re chatting with both need to have Signal installed for the encryption feature to function properly, otherwise Signal doesn’t have enough control over both ends of the conversation.
The app also includes several other useful features on top of the tight security, such as video calling, and disappearing messages that vanish after a certain time period (perfect for those conversations you don’t want to stay on the record).
Telegram Messenger is almost as well-respected as Signal is, although its encryption methods aren’t open source and thus haven’t been as well audited by third-party security experts. What it does have in its favor is a slicker interface, if that’s important to you.
Another black mark against Telegram is that end-to-end encryption isn’t enabled by default, so you need to make sure the Secret mode is activated before you can be sure that no one else is going to tap into your communications. Other types of chat and file transfer are encrypted, but only for part of their journey to other parties.
Those caveats aside, Telegram impresses in most areas, with features like chat backups and disappearing messages (messages with expiry times attached). You can load up group chats, make video calls and more, and in use it’s just as responsive and intuitive as the other messaging apps out there.
If you need all the bells and whistles of an instant messenger, like stickers and audio memos, and even basic photo and video editing software, Telegram is a solid choice. Just be sure to enable the Secret mode for the most secure messaging.
Threema is another secure messaging app that aims to keep your data out of the hands of corporations and governments. The app can be used anonymously, and it’s not just messages but also phone calls that can be securely encrypted.
While secure connections are the mainstay of many messengers, Threema goes one further by ensuring no contact details are saved on their servers, and any messaging data that goes through them is immediately deleted once sent.
The result is that local files remain on your phone, rather than in the open on third-party servers where the information could be intercepted by hackers or data-collection agencies.
For all its security considerations, Threema is still a fully-functional messaging app, that allows you to send images, files, videos, and locations, as well as create groups and set up polls among trusted users.
There’s no need to sign in with an email or other personally identifiable information, reducing the amount of data required to use it. All in all, Threema offers a very secure experience with security and anonymity in mind.
The unfussy, no-frills Silence focuses on keeping your messages safe and secure, with other considerations – like animated animal stickers – some way down the priority list. It deals directly with SMS and MMS, rather than chat protocols that work over the web.
It is in fact a spin-off from Signal, and uses the same open source, ultra-secure encryption methods – regularly audited by security experts in public view to make sure the code hasn’t been cracked or unlocked by whatever government agency wants to get its hands on your conversation history. If you wanted to, you could use Silence and Signal together.
So you get all of the benefits of SMS/MMS, like the ability to use it without Wi-Fi, as well as all the drawbacks, like limited support for group chats and no video calling. As you’re using SMS/MMS, your phone network can tell who you’re texting, even if it can’t tell what’s being said thanks to the encryption applied.