UnderKey vs Cloud Storage
Cloud storage services like Google Drive, Dropbox, iCloud Drive, and OneDrive are convenient: files sync across devices, you can access them from anywhere, and you never have to worry about losing them if your phone breaks. But for passports, IDs, financial records, and other sensitive documents, that convenience comes with serious privacy and security risks.
What cloud storage is good at
For most files — work documents, shared spreadsheets, PDFs you want to collaborate on — cloud storage makes sense. It's reliable, backed up, and accessible from any device. If your laptop dies, your files are safe. If you need to share a document with a colleague, you send a link.
But cloud storage is designed for convenience, not privacy. The trade-off is that your files live on someone else's servers, accessible to anyone with your credentials, and subject to the provider's security policies, data retention, and government requests.
Why cloud storage is risky for sensitive documents
Account security is a single point of failure
If someone phishes your password, guesses your security questions, or gains access to a device where you're logged in, they have access to every file in your cloud storage. Two-factor authentication helps, but it's not foolproof.
Files sync to forgotten devices
Cloud storage syncs to every device where you're logged in. If you sold an old laptop without signing out, or left yourself logged in on a friend's computer, your files are accessible from there.
Provider breaches and data requests
- Breaches happen. Major cloud providers have strong security, but incidents occur. In 2014, iCloud was targeted in a celebrity photo leak. In 2012, Dropbox had a security incident that exposed user data.
- Providers can be compelled to hand over your data. Governments can subpoena cloud providers for your files. Providers can also scan your files for content that violates their terms of service.
No control over the encryption key
Most cloud providers encrypt your files in transit and at rest, but they hold the encryption key. This means they can decrypt your files if compelled to do so, or if an employee gains unauthorized access.
A few providers offer end-to-end encryption (Tresorit, Sync.com, ProtonDrive), where you hold the key. This is better, but your account is still a target: if someone phishes your password or gains access to a logged-in device, they can still download and decrypt your files.
How UnderKey is different
| Feature | Cloud storage | UnderKey |
|---|---|---|
| Files stored on remote servers | Yes | No (only on your device) |
| Vulnerable to account hacking | Yes | No (no account) |
| Syncs to multiple devices | Yes | No (vault is device-specific) |
| You control the encryption key | No (provider holds it) | Yes (derived from your pattern) |
| Risk of forgotten logged-in devices | Yes | No |
| Provider can be subpoenaed | Yes | No (no servers) |
| Access requires internet | Yes (to download) | No (encrypted on-device) |
| Decoy vaults | No | Yes (each pattern opens a different vault) |
Hybrid approach: cloud for most things, offline for sensitive documents
You don't have to choose one or the other. A sensible setup is:
- Cloud storage for work documents, shared files, and anything you need to access from multiple devices or share with others.
- Offline encrypted storage for passports, IDs, financial records, crypto seed phrases, and anything you'd panic about if it leaked.
This gives you the convenience of cloud storage for everyday files, and the security of offline storage for the documents that matter most.
What about password-protected files in the cloud?
You can upload a password-protected PDF or ZIP file to cloud storage. This is better than uploading an unprotected document, but it's still not as secure as offline storage:
- The encrypted file is still on a remote server that could be breached or subpoenaed.
- You have to store the password somewhere, and if you store it in the same cloud account, you've gained nothing.
- Password-protected files are vulnerable to brute-force attacks if the password is weak or the encryption algorithm is outdated.
When cloud storage makes sense
Cloud storage is the right choice for:
- Files you need to access from multiple devices (work documents, project files).
- Files you need to share with others (collaborations, team documents).
- Low-sensitivity documents where the risk of exposure is minimal (grocery receipts, old invoices, saved articles).
But for documents that prove your identity or can be used to impersonate you — passports, IDs, birth certificates, financial records, crypto seed phrases — the risk of cloud storage is too high.
What if you lose your phone?
The main argument against offline storage is that if you lose your phone, your documents are gone. This is true, and it's why you should have a backup plan:
- Keep a printed copy of critical documents at home in a locked drawer or safe.
- Store a second encrypted copy on a USB stick or external hard drive and keep it somewhere secure (not in the same house as your phone).
The risk of losing your phone is real, but it's manageable with physical backups. The risk of a cloud breach or account takeover is harder to control, which is why offline storage is the safer default for sensitive documents.
Summary
- Cloud storage is convenient but risky for sensitive documents. Files live on someone else's servers, accessible to anyone with your credentials, and subject to breaches and government requests.
- UnderKey stores documents encrypted on your device, not in the cloud. No account to hack, no server to breach, and you control the encryption key.
- Use cloud storage for everyday files, offline storage for passports, IDs, and financial records.
- Keep physical backups of critical documents at home in case your phone is lost or stolen.