Signal’s New Encrypted Backup: How to Securely Save Your Chat History
For years, one of the biggest challenges for users of the privacy-focused messaging app Signal has been the risk of losing their chat history. Get a new phone or lose your current one, and your messages were gone forever. This was a direct result of Signal’s unwavering commitment to privacy, which meant avoiding the cloud-based backups common in other apps.
Now, that’s changing. Signal has introduced a game-changing feature that offers the best of both worlds: the convenience of backups and the security of end-to-end encryption. You can now securely back up and restore your Signal chat history without compromising your privacy.
The Privacy Dilemma of Cloud Backups
Most messaging apps, like WhatsApp, back up your chats to third-party cloud services like Google Drive or iCloud. While convenient, this creates a potential privacy risk. The cloud provider has access to the encrypted backup files, and in some scenarios, the keys to decrypt them, creating a potential target for hackers or data requests.
Signal’s philosophy has always been to minimize the data it holds and to ensure no one—not even Signal itself—can access your communications. That’s why they’ve developed a new system from the ground up.
Introducing a True Zero-Knowledge Backup System
Signal’s new backup feature is a “zero-knowledge” system. This means Signal has absolutely no access to the contents of your backup file. The entire process is protected by a unique passphrase that only you know.
Here’s how it works:
- Unique Encryption Key: When you enable the backup feature, a unique 12-word passphrase is generated on your device.
- Local Encryption: Your chat history is encrypted on your phone using this passphrase.
- Secure Storage: The encrypted file is then stored in the cloud. However, this file is completely unreadable to anyone without the passphrase, including Signal’s servers.
When you get a new phone, you simply install Signal, choose to restore from backup, and enter your 12-word passphrase. The encrypted file is downloaded, and your passphrase decrypts it locally on your new device.
Your Passphrase is Your Responsibility: A Critical Security Note
This new system places the power—and the responsibility—squarely in your hands. There is one incredibly important rule to understand:
If you lose your 12-word passphrase, your backup is gone forever.
Signal does not have a copy of your passphrase and has no way to recover it for you. This is a feature, not a flaw. It’s the core of what makes the system so secure. Because Signal can’t access your passphrase, it means no one else can get it from them either.
Actionable Security Tip: When you enable chat backups, you must write down your 12-word passphrase and store it in a very safe and secure location. Treat it with the same importance as the keys to your home or your bank password. Consider storing it in a trusted password manager, a physical safe, or another secure offline location.
How to Enable Signal Chat Backup
Activating this new feature is straightforward.
- Make sure your Signal app is updated to the latest version.
- Go to Settings > Chats > Chat backups.
- Tap “Turn On”.
- The app will generate your unique 12-word passphrase.
- Write down the passphrase immediately. Do not proceed until you have a secure copy.
- You will be asked to confirm the passphrase to ensure you’ve recorded it correctly.
- Once confirmed, your device will begin creating your first secure backup.
The Perfect Balance of Convenience and Privacy
This new feature finally solves one of the most significant usability issues for Signal users. You no longer have to choose between keeping your chat history and using the world’s most secure messaging platform.
By creating a zero-knowledge system that relies on a user-held passphrase, Signal has successfully engineered a backup solution that doesn’t compromise on its core promise of privacy. It’s a powerful new tool that gives you control over your data, ensuring your conversations remain exactly that—yours.
Source: https://www.helpnetsecurity.com/2025/09/09/signal-secure-backup-feature/
