The comparison was last updated on 26/Jan/21. Please contact me with any updates, if I have made any mistakes. 

Red = Something of major concern.

Yellow = Something of concern.

Green = Nothing of concern.

Blank = I couldn’t find any information about it.

 Google MessagesApple iMessageFacebook MessengerElement / RiotSignalMicrosoft SkypeTelegramThreemaViberFacebook WhatsappWickr MeWireSession

(in progress)

Overview

Is the app recommended to secure my messages and attachments?NoNoNoNoYesNoNoYesNoNoNoYesNo
Main reasons why the app isn't recommended?

More details



Named as NSA partner in Snowden revelations

Makes money from personal data

Data not protected, not all data protected

No independent & recent code audit and security analysis

Closed source
Named as NSA partner in Snowden revelations

Data not protected, not all data protected

No independent & recent code audit and security analysis


Closed source
Named as NSA partner in Snowden revelations

Encryption not enabled by default

Makes money from personal data

Data not protected, not all data protected

No independent & recent code audit and security analysis

Closed source
No independent & recent code audit and security analysis RecommendedNamed as NSA partner in Snowden revelations

Encryption not enabled by default

Makes money from personal data

Data not protected, not all data protected


Closed source
Bespoke cryptography

Encryption not enabled by default

Data not protected, not all data protected
RecommendedData not protected, not all data protected

No independent & recent code audit and security analysis

Closed source
Named as NSA partner in Snowden revelations

Makes money from personal data

Data not protected, not all data protected

No independent & recent code audit and security analysis

Closed source
Recent security audits are not public

Closed source
RecommendedNo independent & recent code audit and security analysis

Details

Company jurisdictionUSAUSAUSAUKUSAUSAUSA / UK / Belize / UAESwitzerlandLuxembourg / JapanUSAUSASwitzerlandAustralia
Infrastructure jurisdictionWorldwide (rollout on-going, unsure of exact locations, most likely Google Cloud regions) USA (Ireland and Denmark planned); iMessage runs on AWS and Google CloudUSA, Sweden (Ireland planned)UK (and potentially all jurisdictions, given it's a decentralised messaging platform)USAUSA, the Netherlands, Australia, Brazil, China, Ireland, Hong Kong, and JapanUK, Singapore, USA, and FinlandSwitzerlandUSAUSA (unsure of other locations)USA (unsure of other locations)EUMessages: Worldwide (uses de-centralised servers)

Attachments: Centralised server (unknown location)
Implicated in giving customers' data to intelligence agencies?YesYesYesNoNoYesNoNoNoYesNoNoNo
Surveillance capability built into the app?NoNoNoNoNoYesNoNoNoNoNoNoNo
Does the company provide a transparency report?YesYesYesNoYesYesNoYesNoYesYesYesYes
Company's general stance on customers' privacyPoorPoorPoorGoodGoodPoorPoorGoodPoorPoorGoodGoodGood
FundingGoogleAppleFacebookNew Vector LimitedFreedom of the Press Foundation / the Knight Foundation / the Shuttleworth Foundation / the Open Technology Fund / Signal Foundation (Brian Acton)MicrosoftPavel DurovUser pays / Afinum Management AGRakuten / friends and family of Talmon Marco (it's very unclear)FacebookGilman Louie / Juniper Networks / the Knight Foundation / Breyer Capital / CME Group / Wargaming / Merlin International / Lytical VenturesJanus Friis / Iconical / Zeta Holdings LuxembourgLAG Foundation Ltd
Company collects customers' data?YesYesYesNoNoYesYesNoYesYesNoNoNo
App collects customers' data?Yes

(Difficult to assess given the app is integrated into Google's greater ecosystem)
Yes

(Difficult to assess given the app is integrated into Apple's greater ecosystem)
Health & fitness / purchases / financial info / location / contact info / contacts / user content / search history / browsing history / identifiers / usage data / sensitive info / diagnostics / other dataContact info / contacts /
identifiers /
diagnostics /
user content

(Contact info not sent when using anonymously)
Contact InfoYes

(Information not submitted to Apple Store)
Contact info /
contacts /
identifiers
Contact info / identifiers / diagnostics

(Contact info not sent when using anonymously)
Location / identifiers / purchases / location / contact info / contacts / identifiers / usage data / user content / usage data / diagnosticsPurchases /
financial info /
location /
contact info /
contacts /
user content /
identifiers /
usage data /
diagnostics
Contact info /
usage data /
diagnostics

(Contact info not sent when using anonymously)
Contact info / identifiers / usage data / diagnosticsNo
User data and/or metadata sent to parent company and/or third parties?YesYesYesNo

(User data is sent to a third party if a payment is made)
Minimal

(mandatory mobile number sent to third party for registration & recovery)
YesYesNo

(optional mobile number sent to third party for registration)
YesYesNo

(optional mobile number sent to third party for registration)
YesNo
Is encryption turned on by default?YesYesNoYesYesNoNoYesYes (if device supports it)Yes (if device supports it)YesYesYes
Cryptographic primitivesCurve25519 / AES-256 / HMAC-SHA256RSA-1280 (encryption), ECDSA 256 (signing) / AES 128 / SHA-1Curve25519 / AES-256 / HMAC-SHA256Curve25519 / AES-256 / HMAC-SHA256Curve25519 / AES-256 / HMAC-SHA256RSA-1536 & 2048 / AES 256 / SHA-1RSA 2048 / AES 256 / SHA-256Curve25519 256 / XSalsa20 256 / Poly1305-AES 128Curve25519 256 / Salsa20 128 / HMAC-SHA256Curve25519 / AES-256 / HMAC-SHA256ECDH512 / AES-256 / HMAC-SHA256Curve25519 / ChaCha20 / HMAC-SHA256X25519 / AES (unsure of key length / unknown
Are the app and server completely open source?NoNoNoYes (clients Element / Riot, server/API matrix.org) YesNoNo (clients and API only)No (apps only)NoNoNoYesYes
Are reproducible builds used to verify apps against source code? NoNoNoNoAndroid onlyNoiOS and AndroidAndroid onlyNoNoNoNoNo
Can you sign up to the app anonymously?NoNoNoYesNoNoNoYesNoNoYesNoYes
Can you add a contact without needing to trust a directory server?N/A, Google Messages uses RCS, which doesn't use a directory serviceNoNoNoNoNoNoYesYesNoNoNoYes
Can you manually verify contacts' fingerprints?YesNoYesYesYesNoNo (session only, does not provide users' fingerprint information)YesYesYesYesYesYes
Directory service could be modified to enable a MITM attack?N/A, Google Messages uses RCS, which doesn't use a directory serviceYesYesYesYesYesYesYesYesYesYesYesYes
Do you get notified if a contact's fingerprint changes?NoYesYesNoNo (session only, does not provide users' fingerprint information)YesYesNo (setting turned off by default)YesIf contact was previously verifiedN/A
Is personal information (mobile number, contact list, etc.) hashed?N/A, Google Messages uses RCS, which doesn't use a directory serviceNoNoYesMostlyNoNoYesNoNoYesMostlyN/A
Does the app generate & keep a private key on the device itself?YesYesYesYesYesYesYesYesYesYesYesYes
Can messages be read by the company?NoNoYesNoNoYesYesNoNoNoNoNoNo
Does the app enforce perfect forward secrecy?YesNoYesYesYesNo (session keys do change after being used 100 times)NoYesYesYesYesYes
Does the app encrypt metadata?NoNoNoYesNoYesNoYesMostlyYes
Does the app use TLS/Noise to encrypt network traffic?YesYesYesYesYesYesNoYesYesYesYesYesYes
Does the app use certificate pinning?Yes (>=iOS 9.3)YesYesYesYes
Does the app encrypt data on the device? (iOS and Android only)NoYes (if passphrase enabled)YesYes (if passphrase enabled)iOS: Yes (if passphrase enabled); Android: Yes (if master key set in the app)iOS: Yes (if passphrase enabled); Android: Yes (unsure of function)Yes
Does the app allow a secondary factor of authentication?NoNoNoNoYesNoYesYesNoYesYes (password for account used)YesYes
Are messages encrypted when backed up to the cloud?Yes (>= Android P)NoYesN/A, Signal is excluded from iCloud/iTunes & Android backupsYesiOS: Yes
Android: No
N/A, Wickr is excluded from iCloud/iTunes & Android backupsN/A, Wire is excluded from iCloud/iTunes & Android backups
Does the company log timestamps/IP addresses?YesYesNoYesYesNoYesYesNoSomeNo
Have there been a recent code audit and an independent security analysis?NoNoNoNo

(Matrix's encryption library reviewed by an independent party)
Yes (October, 2014)NoYes (November, 2015)Yes (October, 2020)NoNoYes (August, 2014)Yes (March, 2018) No
Is the design well documented?NoSomewhatSomewhatSomewhatSomewhatNoSomewhatSomewhatSomewhatSomewhatSomewhatSomewhatSomewhat
Does the app have self-destructing messages?NoNoYesNoYesNoYesNoYesYesYesYesYes