Signal has released version 8.30, extending its encrypted backup feature to iOS and desktop platforms and completing a rollout that began on Android nearly a year ago. The update brings on-device backup support to Linux, macOS, and Windows for the first time, and standardizes Android’s backup format to match the new cross-platform system.
Two Backup Options
Signal offers two ways to back up chats. Signal-hosted backups are capped at 45 days of media and 128 KB per message for free users, with 100 GB available on paid plans. On-device local backups carry no size restrictions. Both methods are end-to-end encrypted and require a recovery key to decrypt, though hosted backups add a supplemental key that rotates daily inside a Trusted Execution Environment, providing forward secrecy on top of the base encryption.
Signal notes that an on-device backup recovery key can decrypt every past backup file it created, regardless of where those files are later stored. That persistence has already drawn attention from threat actors, who reportedly began incorporating the recovery key into their targeting shortly after the feature launched.
What’s New Under the Hood
With this release, media is stored separately from the backup archive itself, and duplicate files are saved only once rather than repeatedly, cutting down on unnecessary backup and sync overhead. Paying users also gain the option to purge older media from local storage, keeping only thumbnails and pulling full files back from hosted backups on demand.
Disappearing messages set to vanish within 24 hours are excluded from both backup types. Signal clarified that creating a hosted backup does not erase an existing on-device backup, though expired disappearing messages found in local backups will be skipped during restoration.
When a new device is linked to a primary device, it will now retrieve older attachments that were previously missing from the chat history. The iOS client also gains a direct iPhone-to-iPhone transfer option using a local, end-to-end encrypted Wi-Fi Aware connection, which Signal says improves both speed and reliability compared to prior transfer methods.
What Comes Next
Signal says this release marks the completion of the first phase of its backups project. Engineering focus will now shift to improving other parts of the app outside the backup system.
Security teams supporting Signal users on managed devices should be aware that local backup recovery keys represent a durable decryption capability across all historical backups, making their protection and storage a meaningful part of endpoint security hygiene.