Encryption
For highly sensitive content, tagd-ai offers end-to-end encryption. Content is encrypted on your device before upload and can only be decrypted by those with the key.
How Encryption Works
End-to-End Encryption
- Content is encrypted on your device
- Only encrypted data is transmitted and stored
- tagd-ai servers cannot read your content
- Only someone with the decryption key can view
What's Encrypted
- All text content in the tag
- File attachments
- Image captions
- Metadata (titles, descriptions)
What's Not Encrypted
- QR code/short ID (needed for routing)
- Tag existence (tagd-ai knows tags exist)
- Access timestamps (who accessed when)
Setting Up Encryption
Enable on a Tag
- Create or open a tag
- Go to Settings → Security
- Toggle End-to-End Encryption
- Create an encryption key
- Save the key securely - tagd-ai cannot recover it
Important
If you lose your encryption key, you lose access to the content. tagd-ai cannot help recover encrypted data.
Encryption Key Options
Password-based:
- You create a memorable password
- Key is derived from password
- Easier to remember, slightly less secure
Generated key:
- Random cryptographic key
- Very secure
- Must be stored safely
Sharing Encrypted Content
With Key Recipients
To share encrypted content:
- Share the tag link as normal
- Share the decryption key separately
- Recipient enters key to view content
Key Distribution
Share keys securely:
- In-person verbal communication
- Encrypted messaging (Signal, WhatsApp)
- Secure password manager sharing
- Never email keys with links
Team Access
For team use:
- Use a shared password the team knows
- Or use a team password manager
- Key management is your responsibility
Viewing Encrypted Content
As a Viewer
- Open the encrypted tag
- See "This content is encrypted" message
- Enter the decryption key
- Content is decrypted locally
- You can now view the content
Session Persistence
After entering the key:
- Content viewable for session
- Key isn't stored permanently
- Re-enter key after browser close
- Each device needs key entry
Key Management
Storing Keys
Recommended storage:
- Password manager (1Password, Bitwarden)
- Encrypted notes application
- Physical safe (for critical keys)
- Split key storage for high security
Key Rotation
Periodically change encryption keys:
- Decrypt the tag
- Go to Settings → Security
- Click Change Encryption Key
- Enter new key
- Content is re-encrypted
- Distribute new key to authorized users
Multiple Keys (Pro)
For different access levels:
- Master key: Full access
- Limited keys: Specific sections
- Time-limited keys: Expire after period
Technical Details
Algorithms Used
- Encryption: AES-256-GCM
- Key Derivation: PBKDF2 or Argon2id
- Integrity: HMAC-SHA256
Client-Side Encryption
All encryption happens:
- In your browser (JavaScript)
- Before data leaves your device
- Using Web Crypto API
- With no server-side access
Zero-Knowledge
tagd-ai operates with zero knowledge of:
- Your encryption keys
- Your decrypted content
- Who has access (beyond access logs)
Use Cases
Medical/Health Information
HIPAA-sensitive data:
- Patient information
- Medical records
- Health data
Financial Information
Protect:
- Banking details
- Investment information
- Tax documents
Legal Documents
Secure:
- Contracts
- Legal proceedings
- Confidential communications
Personal Secrets
Store:
- Passwords and credentials
- Personal notes
- Private information
Encryption vs Other Security
Comparison
| Feature | Password Protection | Encryption |
|---|---|---|
| Server access | tagd-ai can read | Zero knowledge |
| Key recovery | tagd-ai can reset | Not possible |
| Performance | Instant | Slight delay |
| Use case | Casual privacy | Maximum security |
When to Use Each
Use Password Protection:
- Moderate sensitivity
- Convenience important
- Need password recovery option
Use Encryption:
- Highly sensitive data
- Compliance requirements (HIPAA, etc.)
- Maximum security needed
- Willing to manage keys
Combining with Other Security
Recommended Stack
For maximum security:
- Two-factor authentication on account
- End-to-end encryption on tag
- Access logging enabled
- Strong encryption key
Layered Access
Account (2FA required)
└── Tag (Encrypted)
└── Protected Fields (Password)
Limitations
What Encryption Can't Do
- Protect against key compromise
- Prevent screenshots after decryption
- Stop authorized users from sharing
- Recover data if key is lost
Performance Impact
Encrypted tags:
- Slightly slower to open
- Larger storage size (encrypted)
- Client processing required
- Mobile devices may be slower
Troubleshooting
Wrong Key Error
- Check for typos
- Verify correct tag
- Ensure complete key entry
- Key is case-sensitive
Can't Decrypt
- Verify you have correct key
- Check if key was changed
- Try different browser
- Contact person who shared key
Lost Encryption Key
If you've lost the key:
- Check password managers
- Check secure notes
- Ask anyone who has access
- Data may be unrecoverable
Recovery Prevention
Back Up Keys
Before encrypting:
- Generate/create your key
- Store in password manager
- Create physical backup
- Test that backup works
Test Decryption
After encrypting:
- Log out of tagd-ai
- Log back in
- Try decrypting with backed-up key
- Verify before adding sensitive content