Privacy-focused users and security professionals alike can now leverage **Signal's** comprehensive encrypted backup system, which has reached full cross-platform availability with the release of version 8.30. First introduced on **Android** nearly a year ago, this feature allows users to create end-to-end encrypted backups of their conversations and restore them seamlessly on new or lost devices. ### Dual Backup Options for Enhanced Flexibility The backup system offers two distinct options: * **Signal-hosted backups**: These are limited to 45 days of media and 128 KB per message for free users, with paid plans offering up to 100 GB. * **On-device, local backups**: These come with no size restrictions, providing complete control over data storage. Both methods encrypt backups, requiring a recovery key for decryption. Hosted backups include an additional supplemental key that rotates daily within a Trusted Execution Environment (**TEE**) for an extra layer of protection and forward secrecy. ### The Criticality of Recovery Keys **Signal** emphasizes that an on-device backup recovery key can decrypt all past backup files it encrypted, regardless of their storage location. This highlights the paramount importance of safeguarding these keys, a fact not lost on threat actors who have already begun incorporating them into their targeting scope. ### Latest Enhancements and Cross-Platform Consistency This latest update extends on-device backups to **iOS** and desktop clients, while also standardizing **Android** backups to use the same cross-platform format. A significant improvement is the ability for new linked devices to retrieve missing older attachments from the primary device.  **Signal** has also optimized media storage, now separating media from the backup archive and storing duplicate files only once. This reduces redundant backing up and syncing. Paying users gain a new option to purge old media from local storage, keeping only thumbnails, with the ability to retrieve full media from hosted backups as needed. ### Disappearing Messages and Restoration Logic Crucially, 'disappearing messages' set to vanish within 24 hours are ignored by both backup methods, ensuring they are not included in the archive. While hosted backups do not overwrite local backups, expired disappearing messages from local backups will be skipped during restoration. For **iOS** users, the 8.30 client release introduces direct iPhone-to-iPhone transfers using a local end-to-end encrypted **Wi-Fi Aware** link, promising improved speed and reliability. **Signal** states that this rollout marks the completion of the first phase of its backup project, with engineers now shifting focus to enhancing non-backup systems within the application.