Signal Encrypted Backups for iOS and Desktop with Cross-Platform Restore

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Signal introduces encrypted local backups for iOS and desktop platforms, enabling cross-device restoration across multiple operating systems.

Updates and Features

Signal’s latest updates, released with Signal for iOS version 8.30, introduce encrypted local backups for iOS and desktop platforms. This feature allows cross-device restoration across Android, iOS, Linux, macOS, and Windows. The development followed a year-long cycle informed by user feedback.

Secure Backups

Signal Secure Backups, an end-to-end encrypted service launched in September 2025, now includes local and hosted backup options. On-device storage is supported for Signal Desktop and iOS, while Android has been reconfigured to use the same format.

Backup Options

Previously, Android local backups stored all data in a single archive, leading to excessive storage usage. The updated system separates media files into dedicated folders, enabling periodic synchronization and reducing redundancy. This optimization aids in managing backups on external drives or network-attached storage.

Hosted Backups

Hosted backups remain free for text messages and the last 45 days of media, with a paid tier offering 100GB of media storage. Linked devices can supplement this by requesting missing files from primary devices via end-to-end encrypted transfers. Paid subscribers can also archive older media, retaining thumbnails on devices to reduce storage consumption.

Encryption Details

Hosted backups employ a dual-key encryption system. A user-generated recovery key and a daily-rotating key stored in a Trusted Execution Environment (TEE) protect data, ensuring forward secrecy. On-device backups rely solely on the recovery key, which must never be shared.

iOS Transfer Process

The iOS update includes a redesigned iPhone-to-iPhone transfer process using an end-to-end encrypted Wi-Fi Aware connection. This marks the conclusion of the initial backup project phase, with additional non-backup improvements in development.

Conclusion

Signal’s updates emphasize enhanced data protection and user flexibility, addressing storage efficiency and cross-platform accessibility. The company continues to refine its backup infrastructure while maintaining cryptographic security standards.

Signal’s updates emphasize enhanced data protection and user flexibility, addressing storage efficiency and cross-platform accessibility.