One-Time Links Guide
Maximum security: link works only once. After one download, all access is blocked.
What are One-Time Links?
One-time links provide maximum control:
- Link works exactly once for download
- After download completes, link is invalid
- Same link cannot be used twice
- Creates audit trail of exactly who accessed
- Cannot be accidentally re-shared
How One-Time Links Work
- Upload file
- Enable "One-Time Link" option
- System generates special link
- Share link with recipient
- Recipient downloads files
- Link becomes permanently invalid
- Link cannot be used again
When to Use One-Time Links
Highly Confidential Information
- Trade secrets
- Acquisition details (pre-announcement)
- Executive briefings
- Board materials
- Legal documents
Credentials & Secrets
- Temporary passwords
- API keys and tokens
- Private encryption keys
- Database credentials
- Server access information
Regulated Industries
- Financial services (compliance)
- Healthcare (HIPAA compliance)
- Government (security requirements)
- Law firms (client confidentiality)
One-Time Link Best Practices
Planning
- Verify recipient needs file before sending
- Confirm they're ready to download
- Provide file format details
- Include download instructions
Sharing
- Notify recipient separately (phone/chat)
- Provide link immediately
- Wait until they confirm download
- Link expires after download
Follow-up
- Confirm receipt of file
- Check they could download successfully
- Answer questions about contents
- Secure original file on your end
Combining Features
One-Time + Password
Dual authentication:
- Password required to access
- Only works once per link
- Highest security combination
- Share password separately
One-Time + Expiration
Time-limited single access:
- Link works once AND expires at time
- If not downloaded in time, link expires
- Maximum control over window
One-Time + Access Control
Track and limit:
- Know who downloaded (IP address)
- Track download time
- Prevent re-downloads
- Complete audit trail
User Experience
From Recipient Perspective
- Click link to access files
- See warning: "This is a one-time link"
- Download files normally
- After complete, link is dead
- Cannot access again (file saved locally)
Failed Download Scenario
- If download fails, link is still consumed
- Send new link if needed
- Recipient can try again with fresh link
Multiple Recipients
- Create separate link per recipient
- Each person gets unique URL
- Cannot share link with others (won't work)
- Prevents forwarding
Analytics & Tracking
What's Tracked
| Data | Captured |
|---|---|
| Download time | ✓ Exact timestamp |
| IP Address | ✓ Recipient location |
| File integrity | ✓ If complete download |
| Device info | ✓ Browser, OS |
Access Logs
- See who accessed (by recipient email)
- When they downloaded
- Download completed successfully
- Export logs for compliance
Security Features
Prevents Common Issues
- ✓ Accidental re-sharing (link only works once)
- ✓ Unintended recipients (unique links)
- ✓ Indefinite access (expires after use)
- ✓ No copy/paste sharing (link tied to person)
Compliance Benefits
- GDPR: Controlled access + audit trail
- SOC 2: Document secure transfer
- ISO 27001: Access control measures
- HIPAA: Track who accessed health data
Common Scenarios
Scenario: Sending Trade Secret
Steps:
- Prepare document locally
- Upload to 25cent.cloud
- Enable one-time link + password
- Send link via email
- Call recipient with password
- Wait for download confirmation
- Shred original copy
Scenario: Emergency Access Credentials
Steps:
- Create credentials file (locally encrypted)
- Upload with one-time link
- Message recipient (phone)
- Provide link only after verbal confirmation
- They download and save locally
- Link automatically invalidated
Troubleshooting
Recipient's Download Failed
- One-time link may be consumed
- Generate new link for them
- Verify they have stable internet
- Try again with fresh link
Wrong Recipient Received Link
- Link is now compromised
- Create new link for correct person
- Note old link (consumed, can't be used)
- Send new link to intended recipient
Recipient Can't Download (Link Not Working)
- Check link still valid (hasn't been used)
- Verify no typos in link
- Ensure they have internet access
- Try in different browser