https://supernova.tilde.team/messengers.html My list of favorite secure messaging apps Step-by-step guides and detailed information on secure messaging apps for Android, iOS, Windows, Mac and Linux. My current top picks: Here is a list of the criteria I use to pick the best options. Each app may not have all of these characteristics, but the more that the app has of these in the list the better it will score. Testing is done on both Android and iOS when possible. See my testing setup. * This list is focused on instant messaging and chatting as the primary usage of the app * Apps without trackers given preference * Clients on multiple platforms preferred * Does not expose personal information (for example phone number or email) to other users * Does not leak data (pictures or other data saved unencrypted in browseable folders) * Has ephemeral messages (encryption keys destroyed after a set time) * Has contact verification through key fingerprint or other method Scoring system: Beside each application you will see 4 numbers in colored boxes. The meaning of these numbers follows: 1 This is the lowest score, which means the application does not provide any protection in this category. 2 This score means the application provides some protection in this category. 3 This score means the application provides protection for many items in this category. 4 This score means the application provides complete or almost complete protection in this category. The 4 categories used are: * Privacy of your messages: This means that the contents of your encrypted message are safe from being decrypted by anyone who does not have the decryption key, and they are protected from future brute force decryption. * Privacy of your identity: Information which may reveal your true identity is not exposed by using the application. * Integrity of the system: The infrastructure that the application runs on is trustworthy and messages can be verified to be unaltered. * Resistance to disruption: It would be difficult for any one agent to disable the messaging system, for example by targeting the system's servers. Country of Jurisdiction: Another aspect of each messenger to consider is the legal jurisdiction each app is subject to. This is usually determined by the incorporated status and country of the organization that controls the servers and codebase for the messaging system. Physical server location is not always a factor, for example a server located anywhere in the world is still considered under the jurisdiction of the country where the controlling organization is incorporated. There are various international intelligence sharing agreements, the most well known being the so called "5 eyes", "9 eyes" and "14 eyes" countries. If your data is protected well enough (encryption) and you are able to remain anonymous online then the country of jurisdiction may not be the primary deciding factor for everyday citizens. But if you require extra security the jurisdiction may be more important. You can read more about the "eyes" at https://restoreprivacy.com/ 5-eyes-9-eyes-14-eyes/. Level 1: Beginner Welcome to your new journey into privacy. Everyone should install Signal as the first step towards a more private lifestyle. Easy and secure Signal 3 Privacy of your messages 2 Privacy of your identity 3 Integrity of the system 2 Resistance to disruption Country jurisdiction: USA [5 Eyes] If you have a phone, there's almost no way to get away from SMS. So the best thing you can do is protect your SMS messages at rest with encryption. Signal also offers excellent end to end encryption between Signal users. One draw back of Signal is that everyone you connect with will know your phone number, but for people you are comfortable knowing your phone number that is fine. Pros: * One of the most advanced cryptography protocols * Easy to use, simple replacement for your phone's default SMS app * All data is encrypted locally on the phone * Lots of features * Open source * Messages can be set to disappear up to 4 weeks Cons: * A phone number is required, phone numbers are used to add other contacts * Optionally uses your address book to look for people you know who may use Signal * Messages to non-Signal users are regular non-encrypted SMS * Reliant on one server controlled by the Signal organisation * Based in the USA Other features: * Send photos, videos, audio clips, files, contacts, location * Delivery and read receipts in individual chats * Contact verification through safety number comparison * Alert when a contact's key changes * Re-registration PIN lock * Lock app with PIN or fingerprint Other Signal reviews: Restore Privacy Kuketz Blog Install Signal Detailed Review of Signal Google free Signal fork for Android Molly 4 Privacy of your messages 2 Privacy of your identity 3 Integrity of the system 2 Resistance to disruption Country jurisdiction: USA [5 Eyes] Molly is a fork of Signal for Android that adds a few features and also removes the ability to use regular SMS in the app. There are two flavors of the app, one with Google Firebase and Maps and one without so this provides an additional option for more privacy from Google. One draw back of Molly is that everyone you connect with will know your phone number, but for people you are comfortable knowing your phone number that is fine. Pros: * One of the most advanced cryptography protocols * All data is encrypted locally on the phone * Lots of features * Open source * Messages can be set to disappear up to 4 weeks * Foolproof (cannot send regular non-encrypted SMS messages) Cons: * A phone number is required, phone numbers are used to add other contacts * Optionally uses your address book to look for people you know who may use Signal/Molly * Reliant on one server controlled by the Signal organisation * Based in the USA Other features: * Send photos, videos, audio clips, files, contacts, location * Delivery and read receipts in individual chats * Contact verification through safety number comparison * Alert when a contact's key changes * Re-registration PIN lock * Lock app and database automatically after phone has not been used for a specific time * Block unknown contacts * SOCKS proxy and Tor support Install Molly Detailed Review of Molly Level 2: More anonymous, but centralized Best choice: Threema 3 Privacy of your messages 4 Privacy of your identity 4 Integrity of the system 2 Resistance to disruption Country jurisdiction: Switzerland Threema is a messenger from Switzerland that is very easy use yet is very secure and private. The enterprise version of Threema has been chosen by the Swiss government as their secure messaging platform. Pros: * Very nice look, lots of features, easy to use * Communicate with text, voice or group text chat * Based in Switzerland (great privacy laws) * No personal information such as an email address or phone number is needed to create an account Cons: * No Perfect Forward Secrecy or ephemeral messages * No option for automatic deletion of messages * Can only be used on one device Other features: * One on one video chat available * Send photos, videos, audio clips, files, contacts and location * Create polls * Draw on a photo before sending it * Quote prior messages * Search for words in a chat * Mention other participants * Thumbs up/down on messages in individual chats * Delivery and read receipts in individual chats * Up to 100 participants per group chat * Contact verification through key fingerprint comparison * Optional perfect forward secrecy per contact Other reviews: Kuketz Blog Restore Privacy Install Threema Detailed Review of Threema Alternative: BBMe 3 Privacy of your messages 2 Privacy of your identity 3 Integrity of the system 1 Resistance to disruption Country jurisdiction: Canada [5 Eyes] BlackBerry Messenger is an app which has it's primary focus on enterprise messaging but it is also available for use by individuals for a very low fee. It is a reasonable alternative to Threema if you are looking for a few specific features, such as using one account on multiple devices, using it on a desktop computer or if you need video chat with more than one other person. Pros: * Communicate with text, audio (15 max) and video (15 max) group chat * ID does not contain personal information * Perfect forward secrecy * Use on multiple devices including phones and desktop computers * Choose whether to save photos to the mobile device gallery or not Cons: * Need an email to signup * Based in Canada * Small fee of US $5 per year, paid through Google Store or iOS App Store Other features: * Send photos, videos, audio clips, files, contacts and location * Search for words in a chat * Add messages to a favorites list * Quote and forward messages * Retract a message to delete it from all participants' devices * Clear all messages from a chat or restract the entire chat * Use up to 5 devices with one account * Contact verification by comparing session key or QR code Install BBMe Detailed Review of BBMe Level 3: Peer to Peer or Decentralized Easy to use: TwinMe 3 Privacy of your messages 4 Privacy of your identity 2 Integrity of the system 2 Resistance to disruption Country jurisdiction: France [9 Eyes] TwinMe uses proven TLS encryption to make a direct Peer to Peer connection between devices. The only server involved is a signaling server that helps devices find each other to be able to connect. Messages are sent direct from device to device without going though a server. There is no information needed to signup, you don't have any account at all just an ID on your device that is randomly generated. Connecting with others is accomplished by sharing your device ID. This means though that if you do change devices your old ID will no longer work and any contacts you have made you will need to send the ID of your new device and reconnect with them. Pros: * Communicate with text, voice, video and group text chat * Connections are made directly between your device and your chat partner's device, no server acts as the middle man * No personal information such as an email address or phone number is needed to create an account Cons: * No option for automatic deletion of messages * You can't make a backup or export your keys or messages to move to another device * No contact verification Other features: * Create multiple profiles in the app * Send photos, videos, audio clips, files and streaming music * Manually delete a message including from all participants' devices * Delivery and read receipts in individual chats Install TwinMe Detailed Review of TwinMe For advanced users that self-host: Snikket (XMPP) 2 Privacy of your messages 4 Privacy of your identity 3 Integrity of the system 4 Resistance to disruption Country jurisdiction: Depends on your server location Snikket is a project that is trying to make using XMPP as easy as possible and providing a more unified and consistant experience across platforms. So far they have an XMPP server based on Prosody, an Android client based on Conversations and an iOS client based on Siskin. The clients and server are designed to work together, though they can be used with non-Snikket systems. The server is very easy to setup on your own host and all features and plugins are already enabled by default. Snikket uses the OMEMO protocol to encrypt messages. There is some more meta data saved on the servers other messengers, but that can be mitigated by self hosting your own Snikket server. Pros: * If you self host you control all the information on your own server * Communicate in one on one and group text chats * There are many XMPP servers to choose from if you don't want to host your own * If you self host or choose a good server you do not have to provide email or other identifying information * Snikket provides an easy way for new users to signup using invitations * Messages are preserved if you move to another device or use multiple devices with the same account * Consistant features across Android and iOS Cons: * More meta data is saved on the servers than some messengers (which is why self-hosting is recommended) * Not encrypted by default- you must actively enable OMEMO encryption * No ephemeral messages Other features: * Use the same account on multiple devices * Send photos, audio, files and videos * Quote a message when replying * Edit your most recent message * Use multiple XMPP accounts at once on the same device * Delivery and read receipts in individual chats * Contact verification through key fingerprint comparison Other reviews: Kuketz Blog Install Snikket (XMPP) Detailed Review of Snikket (XMPP) Level 4: Alternative Networks Android or Linux over Tor: Briar Project 4 Privacy of your messages 4 Privacy of your identity 4 Integrity of the system 4 Resistance to disruption Country jurisdiction: None (Tor peer to peer network) Briar is a peer to peer secure messenger that uses the Tor network for connecting devices. Each Briar device has a unique onion address on the Tor network and there are no servers (besides the standard Tor infrastructure) needed to connect to other Briar users. The app has fewer features than many messengers and is only available for Android but if you need secure communications this will provide that without unnecessary frills. Pros: * Communicate with text or photos in one-on-one chats, private groups, forums and post on your own blog * Connections are made directly between your device and your chat partner's device, no server acts as the middle man * Uses the Tor secure network protocol * No personal information such as an email address or phone number is needed to run Briar. There is not even any controlling server where you need to create any account. * Available on F-Droid * Does not require Google Play Services * Can communicate with other Briar users over WiFi, BlueTooth and Tor * Optional setting to delete messages in private chats after 7 days Cons: * Linux app is one-on-one text messaging only * Higher battery usage than most messengers * You can't make a backup or export your keys or messages to move to another device Other features: * Private Groups are chat rooms which are invite-only by the group creator * Forums are chat rooms where any members can add any of their own contacts * You have your own blog where you can write posts, and your contacts will see these posts in a blog feed * "Introductions" lets you give two people in your contact list each other's contact info so they can make their own connection in Briar * Online status indicator * Delivery and read receipts in individual chats Other reviews: Kuketz Blog Install Briar Project Detailed Review of Briar Project Private ad-hoc conversations over Tor: OnionShare 4 Privacy of your messages 4 Privacy of your identity 2 Integrity of the system 4 Resistance to disruption Country jurisdiction: None (Tor peer to peer network) OnionShare is a chat server that runs over the Tor network. It is very easy to start a new chat server on any Linux, MacOS or Windows home PC. Using the Tor netowrk provides all the privacy and security features of Tor. The Tor Browser is used as a client to connect to the server. This system is great for creating a chat session to use at a specific time when all participants can be online. Pros: * Very easy deployment- for server just run OnionShare on a desktop PC, for cleint just install Tor Browser * Multiple platforms supported- Windows, MacOS, Linux, Android * Connection from client to server over Tor * No personal information such as an email address or phone number is needed * Messages are not stored to disk and are destoyed as soon as the client browser tab closes Cons: * Participants must be online to receive messages * No contact verification features * Android user interface is small, disconnects from server as soon as you go to another application * No message notifications * Text messages only Other features: * You see the names of all other connected client sessions Install OnionShare Detailed Review of OnionShare Level 5: Experimental (know what you're doing) Decentralized private network: Session 3 Privacy of your messages 4 Privacy of your identity 4 Integrity of the system 3 Resistance to disruption Country jurisdiction: None (Lokinet peer to peer network) Session runs on top of the onion routing network Lokinet to provide a decentralized messaging system. It uses the Signal protocol for end to end message encryption. This is a new project so is still considered experimental and there will be bugs in the apps. However in testing the app it has been overall a great experience and I think is one of the best prospects for becoming an offical recommendation on my list. Pros: * Send text, photos and files in individual or group chats * The Lokinet system ensures your messages are not stored on any single server while in transit * Set emphemeral message timeout for up to one week * No personal information such as an email address or phone number is needed to create an account * Available for iOS, Android, Linux, MacOS and Windows * Battery usage on mobile devices is better than some other onion routing based apps Cons: * Accounts can only be used on a single device, multi-device support is planned for the future * Still new, bugs exists and features may change * Files are temporarily stored on a central server (encrypted) until the recipients retrieve them Other features: * Add contacts via a QR code * Typing indicators and read receipts (can be turned on or off) * Create closed private groups or open public groups * Mobile app has lockout feature * Disable link previews in messages * Turn notification via Google notification servers on or off * Automatically delete older messages after a specific number per conversation Install Session Detailed Review of Session Proxied Peer to Peer: SimpleX Chat 4 Privacy of your messages 4 Privacy of your identity 4 Integrity of the system 4 Resistance to disruption Country jurisdiction: None (Peer to peer) SimpleX Chat is a newer messenger that has a unique design. For each contact you make you create a unique message queue just for them to send you messages to on a server. They also create a unique message queue for you to send to them. There are no user names to identify specific users of the app, all you know is the location of their messaging queue (which is only for your use). It is like a peer to peer messaging app except that there is a server with a messaging queue in the middle acting as a proxy. This design has several advantages, including being able to send messages to someone even when they are offline. You send a message to their queue (which is always online) and they then retrieve the message right away if they are online, or they pick it up the next time the come online. This also protects the network connection details of the devices themselves, since only the server address is ever known. This is such a simple yet effective design. The messenger also uses good proven encryption methods with the NaCL library, Diffie Hellman ECC key exchange and XSalsa20 encryption. The local database is also encrypted with SQLCipher and I have not detected any data leaks into common storage on Android. The features are limited with texts chats, image and file sending, and group chats. But if you want a really secure and private messenger this is looking very promising. Pros: * No identifying information required * Works like peer to peer but you can still exchange messages while offline * You can host your own message queue server * Mobile and desktop platform clients * Proven end to end encryption methods * Can optionally use the Tor network * Optional ephemeral "burn on read" messages Cons: * Limited chatting features * Need to use a second messaging channel to send an initial invite code to connect with someone and for remote contact verification * A newer app, still has some bugs Other features: * Reply to messages * Contact verification via a hash code * Delete messages on both sides * Audio and video calling Install SimpleX Chat Detailed Review of Simplex Chat Built on DAT: Cabal 2 Privacy of your messages 4 Privacy of your identity 2 Integrity of the system 4 Resistance to disruption Country jurisdiction: None (Tor peer to peer network) Cabal is a new messenger which is built on top of the Dat protocol which uses symmetric keys to validate data and provide access to encrypted dat files. You create a Cabal which is essentially an encrypted database which is replicated with anyone you provide the public key to. This is a very early project so it is yet to be seen what the final security of the system will be, so do not use this for anything truly private. Pros: * Communicate with text in any number of channels created in a single Cabal * Connections are made directly between your device and everyone else connected to the Cabal, no server acts as the middle man * Uses the Dat protocol * No personal information such as an email address or phone number is needed to create a Cabal or join one. * Available for Linux, MacOS and Windows Cons: * Text only right now but sending photos is being worked on * If someone knows your public key they can join and get all history * No option for automatic deletion of messages Other features: * You can be connected to multiple Cabals at once Install Cabal Details on scores for each app: App Privacy of Messages Privacy of Identity Integrity of the System Resistance to Disruption PFS ID ID EP Does EM FP DL No DR Data not Perfect doesn't not NT No Au CV Contact GC Good KC Key PD P2P or OS SH NP Number Ephemeral Foolproof data recoverable Forward Total have require trackers Total Audits Verification Country Change Total Decentralized Open Self of Total messages leaks Secrecy personal email/ done Alerts Source Hosted platforms info phone Signal 3 2 3 Client 2 2 Molly 4 2 3 Client 1 2 Threema 3 4 N/A 4 Client 2 2 BBMe 3 2 3 4 1 TwinMe 3 4 N/A 2 2 2 Snikket 2 4 3 All 4 (XMPP) Briar 4 4 N/A 4 1 4 Project OnionShare 4 4 N/A 2 Many 4 Session 3 4 N/A 4 5 3 SimpleX 4 4 N/A 4 5 4 Chat Cabal ? 2 4 N/A 2 3 4 * EM - Ephemeral messages * ID - ID doesn't have * Au - Audits * PD - P2P or Decentralized Key to * FP - Foolproof personal info * CV - Contact Verification * OS - Open Source columns: * DL - No data leaks * EP - Does not require email * GC - Good Country * SH - Self Hosted * DR - Data not recoverable or phone * KC - Key Change Alerts * NP - Number of platforms * PFS - Perfect Forward Secrecy * NT - No trackers ("N/A" means the key cannot change) Some other apps that are worth considering: Notes within [brackets] are potential negative attributes * BabelNet - Very nice syncing between multiple devices, based outside of the 14 eyes [User interface needs clarified wording, trouble connecting with LineageOS, 1 tracker] * Blabber.im - A fork of Conversations that has a simpler interface * Quicksy (XMPP) - A fork of Conversations that makes it easy to signup, your phone number is used as your ID. December 2018: Recently there have been some troubling laws passed and articles written in the UK and Australia (part of the 5 eyes countries) that may cause issues with trust in applications developed in those countries. Both countries now seem to be pushing for backdoor access for government surveillance to be built into secure messaging applications. Not only will this weaken or break End to End security, but apps that are not open source from those countries may no longer be trusted and may be used for a mass surveillance program. Here are some recent articles. Principles for a More Informed Exceptional Access Debate In a world of encrypted services, a potential solution could be to go back a few decades. It's relatively easy for a service provider to silently add a law enforcement participant to a group chat or call. The service provider usually controls the identity system and so really decides who's who and which devices are involved - they're usually involved in introducing the parties to a chat or call. You end up with everything still being end-to-end encrypted, but there's an extra 'end' on this particular communication. This sort of solution seems to be no more intrusive than the virtual crocodile clips that our democratically elected representatives and judiciary authorise today in traditional voice intercept solutions and certainly doesn't give any government power they shouldn't have. We're not talking about weakening encryption or defeating the end-to-end nature of the service. In a solution like this, we're normally talking about suppressing a notification on a target's device, and only on the device of the target and possibly those they communicate with. That's a very different proposition to discuss and you don't even have to touch the encryption. -Ian Levy is the technical director of the National Cyber Security Centre, a part of GCHQ. -Crispin Robinson is the technical director for cryptanalysis at GCHQ. Australia passes new law to thwart strong encryption The new law, which has been pushed for since at least 2017, requires that companies provide a way to get at encrypted communications and data via a warrant process. It also imposes fines of up to A$10 million for companies that do not comply and A$50,000 for individuals who do not comply. In short, the law thwarts (or at least tries to thwart) strong encryption. Companies who receive one of these warrants have the option of either complying with the government or waiting for a court order. However, by default, the orders are secret, so companies would not be able to tell the public that they had received one. 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