ComparisonAlloiMessageMessengerRiotSignalSkypeTelegramThreemaViberWhatsappWickrWire
TL;DR: Does the app secure my messages and attachments?NoNoNoNoYesNoNoYesNoNoNoYes
Company jurisdictionUSAUSAUSAUKUSAUSAUSA / UK / BelizeSwitzerlandLuxembourg / JapanUSAUSASwitzerland
Infrastructure jurisdictionUSA, Belgium, Finland, Ireland,the Netherlands, Chile, Taiwan,and SingaporeUSA (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)Germany / Ireland
Implicated in giving customers' data to intelligence agencies?YesYesYesNoNoYesNoNoNoYesNoNo
Surveillance capability built into the app?NoNoNoNoNoYesNoNoNoNoNoNo
Does the company provide a transparency report?YesYesYesNoYesYesNoYesNoYesYesYes
Company's general stance on customers' privacyPoorPoorPoorGoodGoodPoorPoorGoodPoorPoorGoodGood
FundingGoogleAppleFacebookNew Vector LimitedFreedom of the Press Foundation, the Knight Foundation, the Shuttleworth Foundation, and the Open Technology Fund, Signal Foundation (Brian Acton)MicrosoftPavel DurovUser paysRakuten, friends and family of Talmon Marco (it's very unclear)FacebookGilman Louie, Juniper Networks, the Knight Foundation, Breyer Capital, CME Group, and WargamingJanus Friis, Iconical, Zeta Holdings Luxembourg
Company collects customers' data?YesYesYesNoNoYesYesNoYesYesNoNo
App collects customers' data?YesYesYesMinimalMinimalYesYesNoYesYesNoMinimal
Is encryption turned on by default?NoYesNoNoYesYesNoYesYes (if device supports it)Yes (if device supports it)YesYes
Cryptographic primitivesRSA-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-SHA256
Are the app and server completely open source?NoNoNoYesYesNoNo (clients and API only)NoNoNoNoYes
Can you sign up to the app anonymously?NoNoNoYesNoNoNoYesNoNoYesNo
Can you add a contact without needing to trust a directory server?NoNoNoNoNoNoNoYesYesNoNoNo
Can you manually verify contacts' fingerprints?NoNoYesYesYesNoNo (session only, does not provide users' fingerprint information)YesYesYesYesYes
Directory service could be modified to enable a MITM attack?YesYesYesYesYesYesYesYesYesYesYesYes
Do you get notified if a contact's fingerprint changes?NoNoYesYesNoNo (session only, does not provide users' fingerprint information)YesYesNo (setting turned off by default)NoIf contact was previously verified
Is personal information (mobile number, contact list, etc.) hashed?NoNoNoMostlyNoNoYesNoNoYesMostly
Does the app generate & keep a private key on the device itself?YesYesYesYesYesYesYesYesYesYes
Can messages be read by the company?YesNoYesNoNoYesYesNoNoNoNoNo
Does the app enforce perfect forward secrecy?NoYesYesYesNo (session keys do change after being used 100 times)NoYesYesYesYes
Does the app encrypt metadata?NoNoYesNoYesNoYesMostly
Does the app use TLS/Noise to encrypt network traffic?YesYesYesYesYesYesNoYesYesYesYesYes
Does the app use certificate pinning?Yes (>=iOS 9.3)YesYesYes
Does the app encrypt data on the device? (iOS and Android only)Yes (if passphrase enabled)Yes (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?NoNoNoNoNoNoYesYesNoYesYes (password for account used)Yes
Are messages encrypted when backed up to the cloud?NoN/A, Signal is excluded from iCloud/iTunes & Android backupsYesiOS: Yes
Android: No
N/A, Wire is excluded from iCloud/iTunes & Android backups
Does the company log timestamps/IP addresses?YesYesYesNoYesYesNoYesYesNoSome
Have there been a recent code audit and an independent security analysis?NoNoNoNo Yes (October, 2014)NoYes (November, 2015)Yes (November, 2015)NoNoYes (August, 2014)Yes (March, 2018)
Is the design well documented?NoSomewhatSomewhatSomewhatSomewhatNoSomewhatSomewhatSomewhatSomewhatSomewhatSomewhat
Does the app have self-destructing messages?YesNoYesNoYesNoYesNoNoNoYesYes