Looking for a better alternative to email for secure communication? This guide highlights the best secure messaging apps and services, frequently asked questions, as well as some messaging apps and practices you should avoid.
Have you ever whispered something in someone’s ear that you didn’t want others to hear?
We all have. These days, many of us spend more time talking to people online than we do face to face. Do you ever say (or type or show) anything that you don’t want others to hear (or read or see)? If so, you had better be using some kind of encrypted messaging app to do it.
In this new and updated guide, we’ll talk about why you need to use a secure messaging service. Then we’ll take a quick look at the latest versions of several secure messaging apps and the services they run on, along with some important characteristics to look for. As you’ll see, each has its own pros and cons, and each takes a different approach to the problem of providing secure messaging capabilities.
Why you need to use secure messaging
When you chat with someone online, you might assume that only yourself and the other person are privy to the conversation. But as we’ve learned over the years, there are lots of groups that are expending considerable effort to spy on your communications. Whether it is corporate surveillance or government agencies snooping up data, your private information is under attack.
- Corporations want to read your messages so they can better target ads to you or sell your personal information to the highest bidder.
- Hackers want to use the information to steal your identity, break into your bank account, sell your company’s new business plans to the competition, or blackmail you with those pictures from that wild night in Vegas.
- Governments want to know everything you think and say and do, and maybe even catch a terrorist or two.
Unless you are using a secure messaging service, any or all of these groups will have an easy time intercepting your messages should they choose to do so.
The situation has gotten even worse with governments forcing people to work from home to protect against that virus. Businesses generally have better internal security than someone sitting on their sofa at home, exposing even your company communications to greater threats than before.
That’s why there has been a boom in new messaging services that claim to be private, secure, anonymous, or any combination of those. But most of them fail to do the job for one reason or another. Some only protect your messages in transit, while leaving them accessible to the employees of the service. Others are owned by companies with bad reputations for protecting your privacy. Some may even have been hacked by the NSA or other national intelligence agencies. However, all hope is not lost.
Here are some secure messaging apps that make the grade…
Best encrypted messaging apps
We’ve tested quite a few messaging services over the years. The ones listed here are the ones we consider to be the best options for secure messaging.
Signal – The most secure messaging app
Signal is one of the two messaging apps that really benefited from WhatsApp’s privacy problems in January 2021. A tweeted recommendation from Elon Musk during the crisis certainly didn’t hurt. And since then, Signal continues to get lots of attention.
Signal is generally considered to be the most secure messaging service available. Originally published by Open Whisper Systems, their encryption protocol (the Signal Protocol) is so good that many other services (including giants like WhatsApp) base their own encryption protocol on it. Signal is end-to-end encrypted, open source, and completely free of charge. It allows you to create disappearing messages (a.k.a. self-destructing messages), has successfully completed third-party audits, and also publishes Transparency Reports.
And if that wasn’t enough, it has recommendations from top privacy advocates including Bruce Schneier and Edward Snowden.
However, Signal does come with a few drawbacks. Perhaps most problematic, it requires a telephone number for registration. This, of course, links what you do on Signal to your identity through your phone number, which could be a dealbreaker for some people. Fortunately, there are some workarounds for the Signal phone number registration issue. And of course, you can also use another one of the secure messaging apps listed below.
+ Pros
- End-to-end (E2E) encryption
- Encryption algorithms: Signal protocol, with Perfect Forward Secrecy (PFS) for text messages, voice messages, and video calls
- Open source
- Disappearing messages (aka self-destructing messages)
- Published transparency reports and security audits
- Logs minimum amount of data
- Does not log IP Addresses
- Can replace your phone’s SMS messaging app
- Focus is totally on individual users
- All Signal products are free of charge
– Cons
- Requires a telephone number to sign up
- Does not support 2FA (Two-Factor Authentication)
https://signal.org
Read our Signal Messenger review for more info.
Wire – Secure messaging and collaboration app
Wire is a well-regarded corporate collaboration suite with secure messaging, group chat capabilities, file-sharing, and the ability to collaborate securely with external clients. For this roundup, we reviewed Wire (free version), a secure messaging app for individuals. According to third-party testing, the Proteus protocol that Wire relies on is secure. Like Signal, Wire is open source and gives you self-destructing messages. Also like Signal, Wire requires some personal information to create an account, either an email address or a phone number. However, you can always use a burner temporary disposable email for this.
Judging on its technology, Wire messenger is a great secure messaging app for individuals. On the downside, there are only approximately 500,000 Wire Free users. Another drawback is that the company has announced they will be focusing more on corporate users, rather than individuals. Take this into account if you are looking for a long-term solution to your encrypted chat app needs.
+ Pros
- End-to-end (E2E) encryption
- Encryption algorithms: Proteus protocol, WebRTC (DTLS, KASE, SRTP) with PFS
- Open source
- Self-destructing messages
- Published transparency reports and security audits
- GDPR compliant
- Wire Personal is free
– Cons
- Registration requires email address or phone number
- Some logging of personal data
- Does not support 2FA
- Small number of Wire Personal users (roughly 500,000)
- Company focus is now on the corporate market, not individual users
https://wire.com
Here’s our full Wire Messenger review.
Threema – Anonymous messaging app with no data collection
Threema is one of the less well-known secure and private messaging apps. With around 5 million users and over 8 years on the market, it is a mature, powerful product that somehow never gained a massive following like Telegram, or widespread fame like Signal. But none of this means that Threema isn’t a good option for certain use cases. Here’s why…
First, you can use Threema totally anonymously. Unless you choose to link the app to an email address or phone number, the only way to identify a user is through a randomly generated ID that has no connection to any user-identifiable data. Likewise, each user’s private key is stored on their device, meaning only the user of the relevant device can read messages sent to it.
Note: You have the option to securely back up your Threema ID, contacts, groups, and other data in a Threema Safe which can reside on the company’s servers or on your choice of other location.
Threema offers a business/education version of the product, along with add-ons for broadcasting messages to Threema groups, and an API to use the Threema message network with your own software.
Even Threema’s relative obscurity can be an advantage in some circumstances. Anyone trying to spy on, hack, or otherwise tamper with a messaging service is much more likely to target the services with larger user bases or greater notoriety. There can be advantages to being overlooked.
While there is currently no free version of Threema, you can still purchase this app through the Threema store for direct download, or the Google Play and Apple stores.
+ Pros
- End-to-end (E2E) encryption
- NaCl open source encryption
- Anonymous messaging; no telephone number or email address needed
- Text and voice messages, voice and video calls, file sharing, polls, groups and distribution lists
- Mobile apps plus browser-based, secure desktop chat
- Transition to Open Source is complete
- No IP Addresses or metadata logging
- They own all their own servers for better security and privacy
- Regular security audits and transparency reports
- GDPR compliant
– Cons
- Small user base
- No 2FA
- No free version
https://threema.ch/en
See our Threema review here.
Telegram – Secure messaging app with 500+ million users
Telegram was the biggest beneficiary of the WhatsApp privacy issues at the start of 2021. How big a beneficiary? Telegram gained tens of millions of new users in just the first few weeks of 2021.
It doesn’t matter how secure and private a messaging app is if you can’t talk to anyone with it. When a messaging service has over a billion users like WhatsApp or Facebook Messenger, the odds are high that the people you want to chat with already have an account. When a service has less than a million users (Wire, for example) the odds that the people you want to talk to already have an account are pretty small.
Telegram occupies the middle ground. With over 500 million active monthly users, the odds that the people you need to talk to already have an account are pretty darn good. And the service is free, too. So let’s talk about the other characteristics of a secure messenger service.
While we love the widespread acceptance of Telegram, and the ever-expanding feature set, we do have some concerns about the service. Communications in Telegram are not end-to-end encrypted by default. Only voice calls and Secret Chats are E2E encrypted. Unless you use one of these two modes, your communications within Telegram are not really secure. Even if you do use the E2E encrypted parts of the service, MTProto, the encryption protocol used by Telegram, is questionable at best, insecure at worst – all depending on who you ask. Besides, Telegram logs more user information than the other services listed here.
Whether Telegram is an option for you depends heavily on your threat model and use cases. You may well find that access to the rich feature set and huge user base of Telegram outweighs the questions about exactly how secure and private Telegram really is. If you do decide to give Telegram a try, make sure to use a good VPN service as well. Hiding your IP address and physical location using a VPN goes far toward overcoming the privacy concerns of all that user data logging.
+ Pros
- End-to-end (E2E) encryption
- Encryption algorithms: MTProto, a custom protocol
- Open source apps and Telegram Database Library
- Self-destructing messages
- Users can be logged in on multiple devices simultaneously
- Supports Two-Step Verification
- GDPR compliant
– Cons
- Registration requires a phone number
- E2E encryption only for voice calls and Secret Chats
- Servers are not open source
- Lacks published formal third-party audits
- Logs IP Address and other metadata
https://telegram.org
See our Telegram review here.
Wickr Me – Ephemeral, anonymous messaging app (now owned by Amazon)
Wickr is another great option for a secure messaging app. The Wickr product line contains free and paid versions targeting both individuals and teams/businesses. In our Wickr review, we concentrated on Wickr Me, the free, personal version of Wickr.
One drawback, however, is that Wickr was purchased by Amazon in 2021. Many saw this as a strategic business move to win military contracts. While the optimist would say that Wickr will now have major financial backing and longevity, the pessimist my view Amazon with scorn. You can decide for yourself.
On a positive note, the company has been hard at work expanding their product line since our first review. Now they offer Wickr Pro, a personal/small team solution with different paid tiers, Wickr Enterprise, designed to provide a fully scalable, secure, collaboration platform, and Wickr RAM, a version optimized for military use.
Wickr Me is built on the same code base as the company’s paid commercial offerings, with some features only turned on for the paid versions. While both Wickr Me and Signal are super secure services, they have a number of functional differences that could lead you to choose one over the other.
- Wickr Me uses anonymous accounts. You do not have to provide a phone number, email address or any other personally identifiable information to create an account. This might be more appropriate for your threat model than Signal’s phone number based accounts.
- All Wickr Me content is ephemeral. While Signal lets you decide whether a message must self-destruct or not, Wickr Me doesn’t give you a choice. All messages and attachments self-destruct. The only control you have as a Wickr Me user, is over how long content lasts before it ceases to exist.
If anonymity is important to you, and you are okay with everything you send disappearing after a few days, Wickr Me could be the secure messenger for you.
+ Pros
- Client-side end-to-end (E2E) encryption
- Encryption algorithms: AES 256, ECDH521, and RSA 4096, with Perfect Forward Secrecy (PFS)
- Anonymous accounts
- Ephemeral messages and attachments
- Burn-On-Read messages and attachments
- Published Transparency Reports and Security audits
- All user content is forensically wiped from the device after it expires
- Does not log IP Addresses or Unique Device ID
- Does not record user metadata
- GDPR compliant
– Cons
- Code is publicly visible on GitHub, but not open source
- Message handling is unusual
- Based in the United States
- Now owned by Amazon
https://wickr.com
Note: As an alternative to Wickr Me (free version), you can also get the “Basic” version of Wickr Pro, which includes more options and is also free.
See our Wickr Messenger review for more info and a comparison of the different versions.
Messaging apps and practices to AVOID
So now that we’ve covered the best secure messaging apps above, let’s touch on another topic: messaging apps to avoid.
1. WhatsApp (owned by Facebook)
Sure, WhatsApp may be encrypting your messages – but that doesn’t make it a safe and secure solution. It is owned by Facebook and operates under US law. Here are a few reasons to avoid WhatsApp:
- WhatsApp collects metadata about every user, which can be exploited by Facebook and/or handed over to government agencies. This data includes your name, IP address, mobile number, location history, cell network, contacts, and device type.
- Facebook and WhatsApp will be forced to share users’ encrypted messages with British police under a new treaty.
- Reports suggest governments can easily access encrypted WhatsApp data through “WhatsApp Web”.
- In early 2021, news broke about major privacy policy changes at WhatsApp, which puts more data in the hands of Facebook.
Check out our guide on the best alternatives to WhatsApp.
2. Keybase (now owned by Zoom)
Keybase, which has grown in popularity over the years, sold out to Zoom back in 2020. We covered the story more in our Keybase review.
We know that Zoom is not a business that respects the privacy or security of its users. In fact, there have been numerous scandals with Zoom over the past few years. It’s also worth noting that Zoom has questionable ties to China. In fact, it was even busted routing user data through China.
With Zoom now owning Keybase, we can no longer recommend it.
3. Regular (unencrypted) SMS text messages
While this does not fall under the category of encrypted messaging apps, it’s still worth repeating. If you expect any privacy or security, don’t use standard (unencrypted) text messages.
These text messages can easily be seen by your mobile carriers and the entities they share data with. Additionally, regular text messages are susceptible to man-in-the-middle attacks and also eavesdropping by Stingray devices.
It is important to realize that this applies to SMS messages sent by Signal too. If you configure Signal to manage your SMS messages, it can send and receive SMS. But there is no way to encrypt SMS messages, so even if Signal is managing them, SMS messages go out unencrypted.
Characteristics to look for when selecting an encrypted messaging app
What characteristics should you look for when selecting an encrypted messaging app or service? Even if you have some very specialized requirements, these are characteristics you should definitely look out for:
- End-to-end (E2E) encryption
- Third-party testing / reviews
- Open source code
- Self-destruction
- Limited user data collection
- The specific features you need
- Anonymous signup options
End-to-end (E2E) encryption
End-to-end (E2E) encryption is the #1 characteristic to look for in a secure messaging service. When a messaging service uses end-to-end encryption, only the people who are communicating can read the messages. No one else, not even the company providing the service, can read the messages. Whether you decide to go further down the E2E rabbit hole or not, the key thing to remember is this: If a service doesn’t offer end-to-end encryption, it is not secure.
However, there are two additional conditions that an end-to-end encrypted service must fulfill to ensure it is secure. First, it must use proven encryption algorithms. Second, the end-to-end encryption must be applied to your messages. So let’s look at those two conditions a bit more.
Trusted encryption algorithms
The security of E2E encryption assumes that no one can break the encryption. Or more realistically, it would take a vast amount of time to break the encryption being used. Vast as in millions or billions of years. This normally isn’t a problem. That’s because messaging services typically use trusted encryption algorithms. Algorithms like Signal‘s Signal protocol have been analyzed by cryptographers and shown to be secure against any reasonable attacks. If a service doesn’t use trusted encryption algorithms, it doesn’t mean that the service isn’t secure, but it is something to consider.
End-to-end encryption is turned on
E2E encryption is only useful if it is turned on. Most secure messaging services have E2E encryption turned on by default. Telegram, on the other hand, does not. You need to be sure that you are using Telegram’s Secret Chat system or communicating by voice messages if you want E2E encryption to be turned on in Telegram.
Third-party testing / reviews
One of the big concerns when dealing with any kind of secure messaging service is being able to validate their claims. There are a few different questions you need to answer for yourself:
- What is the service’s definition of “secure?” One service might take a zero-knowledge approach, encrypting/decrypting all messages in the client with the servers having no access to your passwords and encryption keys. Another might use TLS to secure data in transit, and encrypt it at rest on their servers, using their own encryption keys. Both can claim their service is secure, but they would both be using different definitions of the word “secure.”
- What is your threat model? You need to understand what threats you are trying to protect against. If all you want security against third parties spying on your messages while they are zooming back and forth across the Internet, that’s one type of security. If you want your messages to be secure against someone (the NSA perhaps) getting into the messaging service’s servers and decrypting your messages using their copy of your encryption keys, that is an entirely different level of security. Which one you need to search for depends on your threat model.
Once you have the answers to the first two questions, you need to decide if the service you are considering is fit for your particular situation. But how?
Is it practical for you to validate their claims yourself? Knowing that a secure messaging service you are interested in has open source code is great. But can you analyze their code to see if it really delivers on their claims? I certainly can’t. Nor can I do penetration testing or any of the other tests that would be necessary to see whether a service really delivers what it promises.
This is where third-party testing, audits, and reviews come in. Many companies now hire third-parties to come in and validate the service. The exact testing that they get done varies, as does the amount of test results they publish. But this kind of testing can at least give us some sense whether or not a product delivers on their marketing promises.
Open source code
Open source code can also make us more confident that a service will deliver on its promises. Why? Not because you or I are likely to review their source code looking for back doors or flaws in their algorithms. But because it is possible for someone to do exactly that. There are people out there who can, and do, dig into open source code looking for problems.
The more popular a messaging service is, the more likely that people are looking at the code, ready to call out problems. The simple fact that there are people willing and able to go through open source code like this means that errors are likely to get fixed sooner, and anyone trying to do something sneaky in the code will get called out publicly.
Self-destruct messages
The idea of providing security through self-destructing messages has been around for a long time. Today’s secure messaging apps have revived the idea of self-destructing messages, although they aren’t quite as dramatic about it as the old Mission Impossible team was.
Some services allow you to set specific messages to self-destruct a certain amount of time after they are read. Wickr Me goes so far as to make self-destruction the basis of their service. All messages and attachments will self-destruct after a certain amount of time. Depending on your use case for a secure messaging service, this could be a crucial feature.
Limited user data collection
Just because all your messages are securely E2E encrypted, it doesn’t mean that the service has no information about you. Most services collect a certain amount of user data. This could be your email address, your phone number, the IP address you connect to the service from, what time you connect, who you connect to, and so on. While collecting this kind of information might not compromise the security of your messages, it does reduce your privacy.
Depending on your threat model, the amount of user data a secure messenger service collects may not be important. If it is, you can easily reduce the impact of this data collection by using a VPN while using the messenger service. A VPN will hide your IP address and your location, even from the apps on your devices. Some of our top-recommended VPNs include:
- NordVPN – Based in Panama, zero logs, fast speeds, apps for all devices (see our NordVPN review)
- Surfshark – Based in the British Virgin Islands, zero logs, very low prices (see our Surfshark review)
Note: A VPN is not a silver bullet that hides all your metadata. It is just one of many privacy tools you should be using for basic digital self-defense. However, a VPN will securely encrypt traffic between your device and a VPN server, while also concealing your true location and IP address. See these best VPN services for more options and info.
The specific features you need
The security and privacy of a messaging app or service means little if it doesn’t have the features you need. Happily, most of the top secure messaging services continue to add features, reducing the risk that the one you want will be missing something you need. For example, the ability to run on multiple platforms is virtually a necessity, whereas the ability to send video messages or voice memos may or may not be, depending on your use case.
One “feature” to look for in particular is compatibility. Specifically, compatibility with the secure messaging services used by the people you need to exchange messages with. Telegram’s user base is growing rapidly and has over 400 million users. The rest of the top services have a small fraction of that user base. Depending on circumstances, you may need to compromise on the security and privacy front to be able to communicate with the people you need to reach.
Secure and Encrypted Message App FAQs
In this article, our goal was to give you several options to choose from when looking for a secure and private messaging app. But some people out there want us to pick a single winner. By far, the most frequently asked question we’ve heard when researching this topic is:
What is the most secure and private messaging app?
We get it that you want us to tell you that one particular messaging app is the most secure and private. But we’re not going to do it. While we have our own opinions on the subject, we prefer to defer to the 82nd Airborne. They recommended Signal and Wickr as the secure and private messaging apps to use in a combat zone. Who are we to argue.
Conclusion on secure messaging apps
Secure messaging apps remain a great alternative to standard email communications. We’ve said this for years, and even Edward Snowden agrees.
The secure messaging apps and services listed here each takes a slightly different approach to the problem of keeping bad guys out of your business. We’ve given you a quick overview of each of them here. We urge you to think hard about your circumstances, then decide which of these quality products looks best to you.
Here are the encrypted messaging apps we have reviewed on RestorePrivacy:
This guide on the best secure messaging apps was last updated on February 17, 2022.
Time-Sensitive Question:
But first, thank you for such terrific and helpful reviews and analyses.
Q: Are you aware, and can you please advise, of any ephemeral messaging Apps, either text or email, that do not first require installation, registration, or any such enrollment or participation “parity” by recipient? In essence, a low threat operating context where one-way, vanishing message settings are of higher importance than anonymity, ongoing dialogue security, or other external and technological protections other than perhaps deactivating screen shots and other modes of “amateur” user retention in a Mac/iPhone operating environment. Thank you in advance for suggestions.
Preferably text, and not Gmail!
TeleGuard https://teleguard.com/en new best? Free, no registranon, not data, no phone number, full server and location Swiss!
How about self destructing messages?
restoreprivacy.com please test Teleguard! TeleGuard https://teleguard.com/en new best? Free, no registranon, not data, no phone number, full server and location Swiss!
restoreprivacy.com please test TeleGuard! TeleGuard new best? TeleGuard free, Swiss server, no registration!
Hi Heinrich. What about TeleGuard. Looks promising.
what is your opinion about Olvid messenger and anonymous messenger
@vasuki the fact that Olvid went open source is a good sign. Otherwise, I do not have experience with it. Do you use it? If so, why do you like Olvid?
Linphone is defintely worth a look. It comes with end-to-end encryption, is free and open source. It is similar to Jitsi.
https://www.linphone.org/
One other open source messenger that looks very well done is Status. A privacy website out of Europe gave it a good review, but they pointed out the app’s user base is too small to see how successful it will be. I like the fact that Status is peer-to-peer, as opposed to Signal that uses servers.
https://proprivacy.com/privacy-service/review/statusim
https://status.im/
Teleguard?
h1ttps://teleguard.com/
No registration, no phone number, swiss made
“No registration, no phone number…”
No open source?
Signal does have 2FA via PIN(that can be alphanumeric).
Teleguard? https://teleguard.com/en 1. No registration 2. No phone number 3. Swiss made
How bad is Skype?
It is owned by Microsoft…
All server based chat apps have the terrible weakness that one does not know what code is being run.
Even if the code is published open source and even if third parties perform audit (notoriously easy to cheat) one does not know what is running live.
This applies to Signal. A read flag for Signal is that an Australian fiend tells me that the Australian government that have in the last 2 years brushed aside all human rights, now mandate Signal for transacting with them.
Thus I wonder what this site thinks of Deltachat https://delta.chat/
?
Email servers are used only as encrypted storage for messages. All other data is held on the messenger device in question. Architecturally, Deltachat seems the only choice. (no affiliation).
The concept behind DeltaChat is fascinating! All a user needs to chat with someone is their email address and they do not have to install the DeltaChat’s app. I like how it protects people’s metadata too.
https://delta.chat/en/help#how-does-delta-chat-protect-my-metadata
Olvid just went open source!
@usednew Olvid’s Google and Apple apps are open source, but their server is not. I believe Signal’s server is open source in addition to their apps.
https://github.com/olvid-io
Signal CEO and founder Moxie Marlinspike announced today that he is stepping down and WhasApp Executive Chairman Brian Acton will take the helm until a replacement is found.
https://thehackernews.com/2022/01/signal-ceo-resigns-whatsapp-co-founder.html
Data which FBI and law enforcement can request from encrypted messengers:
https://therecord.media/fbi-document-shows-what-data-can-be-obtained-from-encrypted-messaging-apps/
I want you to review each of these messengers in the future.
From article: https://web.archive.org/web/20210316115538/http://serpentsec.1337.cx/secure-messaging-choosing-a-chat-app
Related articles:
https://write.privacytools.io/my-thoughts-on-security/how-to-choose-a-secure-messenger
https://blog.privacytools.io/choosing-the-right-messenger/
Establishing context: Metadata leaks
To understand secure messaging, you must understand metadata leaks and why they’re a threat.
Metadata leaks are when your messaging app includes metadata in a way that’s not encrypted end-to-end. This includes the dates and times you send messages, who you send them to, how frequently you send messages, and more. Many messengers allow you to set status messages and profile pictures. These are not encrypted, and are thus leaked. The issue with metadata leaks is they can fairly easily reveal sensitive information, even when you don’t expect them to.
Establishing context: Formal verification
To quote Wikipedia (since I’m lazy):
In the context of hardware and software systems, formal verification is the act of proving or disproving the correctness of intended algorithms underlying a system with respect to a certain formal specification or property, using formal methods of mathematics.[1]
Formal verification can be helpful in proving the correctness of systems such as: cryptographic protocols, combinational circuits, digital circuits with internal memory, and software expressed as source code.
Formal verification is the highest possible assurance of security. Formally-verified systems are often referred to as having a formal security proof.
WhatsApp
WhatsApp was the de facto standard, until recently people started moving to Signal. The issue with WhatsApp is that… Well, it sucks for privacy. Their new privacy policy, combined with Elon Musk recommending Signal instead, prompted many people to high-tail it away from the service. WhatsApp also leaks metadata. Needless to say, I don’t recommend WhatsApp.
Telegram
Telegram is WhatsApp’s most direct competitor, but is not significantly better than WhatsApp. It’s commonly touted as a FOSS alternative to WhatsApp, but it has many severe security issues, including a cryptographic protocol that can’t be trusted. Telegram committed one of the cardinal sins of security: homebrew crypto in a production app. Telegram leaks metadata, and its design is not solid. Moreover, Telegram is adding ads, which not only creates an annoyance, but introduces trackers into the app. Although to be fair, they already have trackers in the standard build. Additionally, Telegram doesn’t use E2EE by default, and never supports E2EE in group chats. I think it’s pretty clear that using Telegram is not a good choice.
Viber, Wickr, Wire
I’ve decided to condense these into a single section, since they all have the same major issue: These apps leak metadata. This means they should not be trusted for private communication.
OpenPGP/GPG
PGP/GPG isn’t so much a messaging platform as it is a way of encrypting messages on top of existing messaging platforms. One common way of using PGP/GPG is via encrypted emails. PGP/GPG has had many security issues in the past, including cryptographic attacks, as well as attacks that can infect your system with malware. Some of these issues have gone decades without being discovered, and others have been discovered but simply never fixed. Also, PGP/GPG leaks metadata. PGP/GPG simply doesn’t meet the standards of a modern secure system.
As a fun side-note, you can read about this heap overflow in libgcrypt 1.9.0.
Threema
Threema is an open-source chat app that allows anonymous users. You can create an account without revealing any information about yourself. However, it leaks metadata to Threema’s servers. Threema should usually not be used for private communication.
Matrix
Matrix is a federated platform for communication, but leaks metadata. This makes it not a good choice for secure communication. However, its decentralization makes it better than other apps that leak metadata. It’s worth noting that, on some Matrix clients, E2EE must be enabled manually; while some don’t even support E2EE. Really, Matrix is more suitable as a replacement for Discord and IRC than as a private chat platform.
XMPP
XMPP has mostly the same security properties as Matrix. One important thing to note is that while XMPP supports encryption via OTR/OMEMO, many clients don’t support this by default. Other clients do support these by default. XMPP and Matrix leak the same amounts of metadata. Also, Matrix’s encryption (OLM/megOLM) has received formal verification. While OMEMO has received analysis, as far as I’m aware, it has not received formal verification. OMEMO is generally considered a solid cryptographic protocol. However, due to XMPP’s inherent metadata leaks, XMPP should usually not be trusted for private communication.
OTR vs OMEMO
OTR and OMEMO are encryption protocols for XMPP. OTR is an older protocol, and is mostly deprecated in favor of OMEMO.
Session
Session is an interesting messenger that combines the decentralization and resistance against metadata leaks of a peer-to-peer (P2P) messenger, with the usability of a centralized or federated service, allowing messages to be sent to a user who is not online at the time. This is something normally not possible in P2P messengers. The issue with Session is that its protocol is largely un-reviewed by the greater security community, and therefore it is not known to be secure.
Session is also planning to change their protocol soon, which will invalidate any review Session has already received. While Session is promising, they are simply not ready to be trusted as a secure messenger.
Hush
Hush is another interesting messenger, using the infrastructure provided by Zcash to obtain some interesting security properties. It integrates with a cryptocurrency wallet, which is always a bad sign for secure messengers. However, its innovative design could be a very solid reason for it to make such a decision. Hush is currently lacking the necessary review to be considered secure, but could be a promising platform at some point in the future.
Signal
Signal is a solid choice for a secure chat app. I have a blog post explaining why Signal can be trusted for sensitive communications. One thing to note is that sealed sender, a feature they use to prevent metadata leaks, is enabled by default only for contacts. You can manually enable it for non-contacts, at the risk of increased spam.
Signal does require a phone number to register, but this isn’t really a major issue. You can use Signal with a fake phone number. Signal is also centralized, which might not sit right with people who prefer decentralized systems. Signal’s protocol is well-reviewed, and has even received formal verification. Overall, Signal is a solid choice for secure messaging.
Jami
Jami is a cross-platform, P2P messenger built on top of TLS 1.3. TLS 1.3 uses solid cryptography, and therefore Jami inherits these beneficial security properties. Jami is a good choice for a secure chat app. You should read my notes about Jami.
Briar
Briar is a P2P messenger designed for people with very high threat models, such as journalists. Briar does all communication though Tor, by default, and requires no identifiable information to use. Briar’s protocol is solid, and has even received formal verification. Briar is suitable for people with well-funded, sophisticated attackers after them… Assuming they take other precautions, such as using burner phones or running a Pixel phone with Graphene. Briar is the most solid messaging app that doesn’t require specialized hardware to use.
Briar has an added benefit: It can communicate without relying on the internet. It does this using a Bluetooth mesh net. This creates some very interesting properties, and makes it more resilient than any other messenger app.
Tinfoil Chat (TFC)
TFC is the most secure messaging app currently available. It’s designed to resist attacks by even the most well-funded attackers. However, it requires specialized hardware to use. TFC is for people with the most extreme security requirements of all. TFC’s security is as solid as it gets.
Do you know Olvid?
And do you think about metadata leaks?
https://www.ssi.gouv.fr/entreprise/certification_cspn/olvid-version-0-9-2-pour-android/
How About TeleGuard ?
The signal cannot be trusted due to U.S. jurisdiction. Signal move to panama or switzerland and i say okay
Not to mention the secure messangers on Qubes/Whonix
Dino IM
Onionshare
etc
Please consider adding these apps to your secure messengers list.
SerpentSec: Choosing a Chat App (web archive.org)
https://web.archive.org/web/20210316115538/http://serpentsec.1337.cx/secure-messaging-choosing-a-chat-app
• TinFoilChat (TFC) (most secure)
• Briar
• Jami
• Signal
Links:
• TinFoilChat: https://github.com/FJSingel/Tinfoil-Chat
• Briar: https://code.briarproject.org | https://github.com/briar/briar | https://f-droid.org/en/packages/org.briarproject.briar.android/
• Jami: https://jami.net/
• Signal: signal.org
Also read the serpentsec article [ SerpentSec: Choosing a Chat App (web archive.org)
https://web.archive.org/web/20210316115538/http://serpentsec.1337.cx/secure-messaging-choosing-a-chat-app ] for other considerations and additional, more complete information. You should site info from this site in your reviews of these messengers.
Also consider this on signal:
https://web.archive.org/web/20210201234044/https://serpentsec.1337.cx/signal-sucks-heres-why
https://web.archive.org/web/20210316215659/https://serpentsec.1337.cx/signals-privacy-a-definitive-review
How to download a program/repo on github. On Windows and Linux distros
https://www.computercraft.info/forums2/index.php?/topic/16360-downloading-files-off-github-and-how-to-use-a-repo/
https://www.wikihow.com/Download-a-File-from-GitHub
https://www.quora.com/How-do-I-download-something-from-GitHub?share=1
https://www.instructables.com/Downloading-Code-From-GitHub/
I recommend using Qubes OS or other secure distros to install these programs on (make sure the secure distro/OS is still actively being developed.
https://www.reddit.com/r/privacy/comments/7c7zh8/most_secure_linux_distribution/
Should add a Secure OS category on your site.
Dear SvenTaylor and viewers, I really encourage you to read this article:
Most Secure Messangers:
TinFoilChat (TFC) (most secure)
Briar
Jami
Signal
TinFoilChat and Briar use tor
Briar is on android (fdroid)
yet you could get the repo on any distro if you find the repo and tell the command line to download it.
Source:
https://web.archive.org/web/20210316115538/http://serpentsec.1337.cx/secure-messaging-choosing-a-chat-app
Check Element messenger and what Matrix infrastructure is.
I’ve seen adverts for Sekur… (https://www.sekur.com/). The ads all sound great but any thoughts on this service?
It looks good but my biggest hang up with it is that Sekur is not open source. This, as opposed to Signal, which is. I am glad they are being open about transparency, but the company behind Sekur can change the terms at any time with little notice.
I suggest you use SIgnal instead.
yes you’re right
on there pricing page they say they’re not open source.
Wickr has been acquired by Amazon and is now part of the Amazon Web Services (AWS) team.
While WhatsApp’s adoption of end-to-end encryption is an excellent move, since the messenger is not open source, Facebook can quietly change the terms whenever they like.
https://www.bleepingcomputer.com/news/security/whatsapp-rolls-out-ios-android-end-to-end-encrypted-chat-backups/
> 82nd Airborne. They recommended Signal and Wickr as the secure and private messaging apps to use in a combat zone.
A military combat unit’s threat model is what?
1. Enemy must not intercept messages.
It is not “protect soldier Joe Smith’s identity and phone number”, correct?
Is there another reason why Signal’s phone number requirement would be acceptible?
So there are two potential problems with Signal’s treatment of phone numbers: visibility to the other users and visibility to the server. Both can be removed if you get an anonymous phone number but this is hard.
If you are a member of a relatively large public group (or have many contacts who are relative strangers) then it risks handing out your phone number to an individual bad actor (who harrases you) or if you live in a totalitarian country to a government agent who has you shot.
Signal’s server doesn’t technically see the phone number but in practice it can get it (because of how cryptographic hashes work). Signal solemnly swears not to log it or anything but because of how US law works on this they could secretly be obliged to start logging it. (Heck, ProtonMail got obliged by the *Swiss* government to secretly start logging so what hope does a US-based server have?)
So it’s acceptable if protecting your identity from the US government and all your contacts isn’t really an issue or if you know a place you can get a burner phone or other route to an anonymous number. Otherwise, I would suggest Wire*.
* Wire’s opponents will point out that it says it logs more metadata than Signal and that the company has links to industries with poor privacy practices but then again Signal has received millions from the US government so 🤷♂️.
The US government or US companies can’t get hold of Wire’s data as it is in Ireland so it is covered by GDPR. CLOUD basically explicitly states that it is overruled by other jurisdiction’s data privacy legislation and it seems to be the EU’s position that GDPR trumps CLOUD.
But then Wire and Signal are both on AWS so Amazon could probably be persuaded by the US to log the metadata (that said this would go down badly politically in the EU so the US and Amazon would probably think twice about it).
I have just noticed that this is quickly turning into a discussion about law not messaging so I will disist.
Best luck.
Thanks about the excellent article. How about Viber? It’s quite popular in certain parts of the world.
Viber? You can’t be serious, George? 🙂 Yes, it’s popular, but so is Facebook. I’m in Europe, Viber is pretty popular here. It’s very hard to explain why not to use it, common people like its shiny features… Sadly, they don’t care about privacy…
I haven’t really researched into it. Their claims seem good, end-to-end encryption and messages get deleted from their servers right after delivery. Why would you say they don’t care about privacy? I’d really love to know, since over here it’s the most popular choice (even banks seem to prefer Viber), significantly outnumbering WhatsApp in popularity.
https://www.viber.com/en/security/
Nothing personal, just thought I’d comment on phones and banks…
My experience with banks and phone apps is you sit in an office with some Mr. Manager guy who zips from phone screen to phone screen pushing their apps and others with which they probably earn commissions. “Soon, everyone will be doing this, all your friends are…” If you’re neck deep in Phone Culture, it may seem impressive but objectively, it’s a shell game.
I don’t do anything financial with a phone and get tired of waiting for people fumbling with NFC, QR’s, charge splits and other gimmicks in checkout lines. I set up bank accounts with my kids a few years ago. Couldn’t do it except in person with the kids present on a computer (Mr. Manager, again), makes sense, it’s secure, it’s really us.
Phone financial apps? Kids won’t even use them; they know a Phone OS which takes your data is responsible for all transactions, notifications, etc. The convenience and sense of power users get (for a while unless you have lots of money or get hacked) is very attractive, though.
Ok, I did a quick but more thorough search on the matter and it does look there are several privacy-related issues with Viber. It’s still worth a mention here due to its popularity.
Yes, Viber is not privacy friendly. I had to install it due to some relatives I need to communicate with, but I was constantly bombarded with ads. I don’t have ads on Viber since I use Surfshark ad blocker. But the very fact they have ads in the app should be enough not to use it.
Telegram is somewhat better, but they don’t encrypt messages by default and even when they do, their protocol is not so good.. Signal is probably the best msg app (Wickr or Session too), but unfortunately not many people are using it.
What’s the word on Element?
YES – What is the word on Element / Matrix? Definitely waiting for a review of that! The information here is not encouraging: https://www.hackea.org/notas/matrix.html
“A malicious version of the FMWhatsappWhatsApp mod delivers a Triadatrojan payload, a nasty surprise that infects their devices with additional malware, including the very hard-to-remove xHelper trojan.”
https://www.bleepingcomputer.com/news/security/malicious-whatsapp-mod-infects-android-devices-with-malware/
Facebook is going to implement end-to-end encryption to video and voice calls made on it’s messenger app.
https://www.bleepingcomputer.com/news/security/facebook-rolls-out-end-to-end-encryption-for-messenger-calls/
Have you an idea a paid app, BBM Enterprise ? Fairly reasonable price/ 6 months, but famous a decade for wide using ?
Related to BBMe as it shares the same encryption technology from Blackberry, you could look at Rolo Secure Chat.
It is available on android and ios.
Here is a link to the stores:
[https://i.rolo.chat/download]
Great! This is marvellous Taiwan app. I am trying. Really miss the old time. bBM ping!
Thing would like to understand that, is BBMe actually safe and private as its reputation for decades?
Canada, its mother home-country, 5eyes, though.
It’s worth reading regarding Rolo.chat.
https://forums.crackberry.com/general-blackberry-news-discussion-rumors-f2/rolo-secure-chat-blackberry-secure-1189939/index2.html
Good article from Sessions about Wickr and WhatsApp.
Since they are in direct competition, this article is best here.
I have gotten four people to Sessions and hope to get more.
https://getsession.org/a-messaging-app-that-cant-sell-out/