Signal¶
- Best suited for
- Everyday security; peer-facing pseudonymity with hardened settings. [1] [2] [3] [4]
- Main strength
- Mature content security, adoption and iPhone + PC usability. [1] [2]
- Main weakness
- Mandatory number known to the provider and telecom layer. [1] [2]
- Account identifier
- Registration phone number; optional username. [1] [2]
- Android
- Yes, client listed in the study. [1]
- 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¶
- What the provider learns
- Registration number and limited account data; not normal E2EE content by design. [1] [2]
Other observers¶
- 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
- Published 2026 provider response: creation and last-connection dates for six accounts; not messages. [1] [2] [3]
Encryption and keys¶
- Forward secrecy
- Documented protocol property; depends on clients and linked devices. [1] [2]
- Post-compromise security
- Cryptographic recovery after temporary compromise; not while spyware remains in control. [1] [2]
- Key verification
- Out-of-band Safety Number; AKV does not certify identity and requires the other account’s number. [1] [2]
Metadata and identity¶
- Metadata exposure
- Service knows the number; some account dates were publicly disclosed. [1] [2]
- Global user ID
- Service account remains linked to the phone number. [1] [2]
- Username / discovery
- Optional; no public username directory. [1] [2]
- Push notifications
- Exact APNs payload not captured; manage local notification previews. [1] [2]
Calls, IP and groups¶
- IP exposure to peer
- Calls can be relayed; check the setting and actual network path. [1] [2]
- Relay / TURN
- Enable Always Relay Calls when peer IP exposure matters; the relay sees the IP. [1] [2]
- Groups
- Unknown: not established for the version and configuration in question.
Devices and backups¶
- Multi-device
- Primary iPhone; official desktops linked through the phone. [1] [2]
- Backups
- Unknown: not established for the version and configuration in question.
Audits, limitations and public cases¶
- Audits
- Protocols and AKV examined under distinct scopes; not the whole infrastructure or every binary. [1] [2] [3]
- 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
- Mandatory number known to the provider and telecom layer. [1] [2]
- Public law-enforcement evidence
- Published 2026 provider response: creation and last-connection dates for six accounts; not messages. [1] [2] [3]
Configuration and unknowns¶
- Recommended configuration
- Visibility and discovery: Nobody; fresh username, neutral profile, verified Safety Number, relayed calls when needed. [1] [2] [3] [4]
- Remaining unknowns
- Current network behaviour, distributed binaries and forensic evidence remain incomplete; check version, OS and configuration. [1] [2]
Understand the terms¶
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.