FINDING · DETECTION

End-to-end encryption in messaging apps such as Signal, WhatsApp, and iMessage protects against passive government surveillance but offers limited protection against targeted spyware: if a user's device is compromised, the attacker gains access to all messages regardless of transport-layer encryption.

From 2026-story-defending-messaging-apps — Defending Messaging Apps Against Spyware Using Data Diodes · Abstract · 2026 · FOCI 2026

Implications

Circumvention tools should not treat transport-layer encryption as a complete security guarantee for high-risk users — device-level compromise bypasses all network-layer protections and requires separate mitigation.
For activists and journalists in high-surveillance environments, architectural isolation between network-facing components and secure storage is necessary beyond protocol-level encryption.