Uploading encrypted files

How do I encrypt and upload a file?

1. Open your Files dashboard.

2. Drag files in or use the upload button. As long as your vault is unlocked, encryption happens automatically.

3. Each file is encrypted in your browser under a fresh random per-file key, which is wrapped under your vault key before the ciphertext leaves your device.

4. Keep your browser tab open while your files encrypt and upload. New files are sealed with ShieldFive's post-quantum hybrid suite (ML-KEM-1024 + XChaCha20-Poly1305); your vault key is derived from your master password with Argon2id.

What passphrase strength is required?

For your security, ShieldFive requires strong passphrases:

• Minimum 12 characters
• Must achieve at least 50 bits of entropy (shown by the strength meter)
• Use a mix of letters, numbers, and symbols for best security

The encryption modal includes a strength meter to help you create a secure passphrase. Consider using the built-in passphrase generator for maximum security.

Why do I need to verify my email?

Before your first upload, you should:

• Review the onboarding checklist: A quick reminder that lost passphrases cannot be recovered by anyone, including ShieldFive.

• Verify your email: Protects your account and ensures you can receive important security notifications.

Uploads only require verified email. The checklist is recommended but not blocking.

What are the file size limits?

• Maximum file size: the per-file ceiling today is set by the in-browser upload flow we are still polishing rather than by your plan, so it is currently below the storage bucket's 500 GiB limit

• Large file handling: we will raise that ceiling as the chunked-upload flow lands

• Minimum size: Empty files are not supported

What information does ShieldFive store about my files?

ShieldFive stores only encrypted metadata:

• Filename: Encrypted and never visible to our servers
• File size: Tracked for quota purposes only
• Storage path: Randomized to prevent any file identification

File names and contents are encrypted before they leave your browser. We store only the ciphertext and never hold your keys.

How are storage and transfer quotas enforced?

Before each upload, ShieldFive checks your storage quota. Downloads and share traffic are checked against your transfer quota separately.

• Storage quota: Total encrypted file storage allowed on your plan

• Transfer quota: Monthly download and shared-link bandwidth included in your plan

If you exceed storage, you'll be prompted to upgrade your plan or free up space by deleting files.

Why might an upload be rejected?

Uploads may be rejected if:

• The encryption verification fails (file may have been tampered with)
• Your passphrase doesn't meet minimum security requirements
• You've exceeded your storage or transfer quota
• Your email isn't verified

If an upload is rejected, you'll receive a clear error message explaining how to resolve the issue.

Are there limits on how many files I can upload?

To prevent abuse, uploads are limited to 10 requests per minute. If you need to upload many files, space them out or wait a minute between batches. This limit helps ensure reliable service for all users.

What happens if my upload fails or gets interrupted?

If an upload fails:

• Any partially uploaded data is automatically deleted
• No charges are applied to your quota
• You can retry the upload immediately using the same modal
• There's no resume feature - each upload starts fresh for security