Signal-iOS is an encrypted messaging client that provides secure communication for voice calls, media, and text. It functions as a complete implementation of the Signal Protocol, utilizing end-to-end encryption to ensure that only intended recipients can access transmitted data.
The application distinguishes itself through the integration of advanced cryptographic standards, including the use of elliptic curve cryptography for identity verification and digital signature validation. It employs a double ratchet key exchange mechanism to rotate encryption keys for every individual message, ensuring forward secrecy. Furthermore, the client incorporates post-quantum key encapsulation to protect communications against future decryption threats from large-scale quantum computers.
Beyond its core messaging capabilities, the project maintains consistent security states across multiple linked devices through a synchronization mechanism that distributes encrypted key material. All local message history and metadata are protected by persistent database encryption managed by the operating system. The software is distributed as a native application for the iOS platform.
