WhatsApp¶

Best suited for: Personal use if adoption outweighs metadata minimisation. [1] [2]
Avoid if…: You refuse a number at the service or strongly prioritise metadata minimisation. [1]
Main strength: Adoption when moving friends and family is the overriding constraint. [1] [2]
Main weakness: Strong linkage to phone number, accounts and metadata. [1] [2]
Account identifier: Phone number, address book and Meta ecosystem. [1] [2]
iOS: Yes, client listed in the study. [1] [2]
Android: Yes, client listed in the study. [1]
Windows: Yes, client listed in the study. [1] [2]
macOS: Yes, client listed in the study. [1] [2]
Linux: Unknown: not established for the version and configuration in question. [1] [2]
Confidence and scope: Scope-limited documentary evidence; production metadata and distributed binaries not experimentally verified. [1]

What your contact learns¶

What the contact learns: The contact receives messages and the profile you share, and can keep a copy. [1] [2]

What the provider learns: Number, usage graph, IP and service information remain exposure surfaces. [1] [2]

What the network / ISP learns: The network sees destinations, timing and volume; Tor or a relay changes the observer. [1] [2]
Apple / Google exposure: Store, installation and push can create metadata; exact profile linkage depends on the OS and was not tested here. [1] [2]
Public law-enforcement evidence: A 2025 DOJ complaint cites WhatsApp communication and group records; plaintext provenance and exact returned fields are not fully separated. [1] [2]

E2EE: Default E2EE for personal messages and calls; backups need consideration. [1] [2]
Forward secrecy: Unknown: not established for the version and configuration in question.
Post-compromise security: Unknown: not established for the version and configuration in question.
Key verification: Unknown: not established for the version and configuration in question.

Metadata exposure: Number, usage graph, IP and service information remain exposure surfaces. [1] [2]
Global user ID: Unknown: not established for the version and configuration in question.
Username / discovery: Unknown: not established for the version and configuration in question.
Push notifications: Unknown: not established for the version and configuration in question.

IP exposure to peer: Calls can use a relay; Meta remains the central operator. [1] [2]
Relay / TURN: Unknown: not established for the version and configuration in question.
Calls: Documented calls; their network path must be distinguished from messaging. [1] [2]
Groups: Unknown: not established for the version and configuration in question.

Multi-device: Unknown: not established for the version and configuration in question.
Backups: Properties depend on settings; chat E2EE alone does not establish backup guarantees. [1] [2]

Audits: Unknown: not established for the version and configuration in question.
Source code and binaries: Repositories and component-specific scopes recorded in Phase 2; no current binary rebuilt bit-for-bit here. [1] [2]
Main weakness: Strong linkage to phone number, accounts and metadata. [1] [2]
Public law-enforcement evidence: A 2025 DOJ complaint cites WhatsApp communication and group records; plaintext provenance and exact returned fields are not fully separated. [1] [2]

Recommended configuration: Control devices, identities, notifications and files; verify client, version and calling path. [1] [2]
Remaining unknowns: Current network behaviour, distributed binaries and forensic evidence remain incomplete; check version, OS and configuration. [1] [2]

End-to-end encryption — E2EE

Participants’ devices control content keys. The transport server should not read ordinary messages. Learn more

Metadata

Data around the exchange: accounts, IP, timing, volume, devices or groups. Learn more

Pseudonymity

Use an identity different from your civil identity. It can still be linked to you. Learn more

Network anonymity

Reduce the ability to link traffic to your network address or its destination. Learn more

The detailed evidence is maintained in the French Phase 2 register. The translation is a restatement, not new evidence.