Attaching a file to an email makes a permanent copy in at least two mailboxes. A temporary secure link for sharing files does the opposite: the file sits in one place, access ends at a deadline or after one download, and the message you send contains nothing but a link.
Not every temporary link offers the same protection, so the first decision is which kind fits the file. The second is setting it up so the handoff leaves nothing behind. This guide covers both, with step-by-step instructions for a one-time file link and a section on using a secret sharing tool with file attachments without tripping over the usual mistakes.
What a temporary file link does, and what it does not
A temporary link limits access to the stored copy. That is a real improvement over an attachment, and it has limits worth being clear about.
- Expiry removes the link after a time. It narrows the window in which a forwarded or old message can still be used.
- A view or download limit ends access after a number of opens. A one-time link is the strict version: one download, then the stored file is gone.
- A passphrase adds a second factor for links that might be seen by someone other than the recipient.
- None of these retrieve a file after it has been downloaded, or stop the recipient copying it. The link protects the handoff. The recipient now has the file.
Pick the method by the file
| Method | Good for | Watch out for | | --- | --- | --- | | Cloud storage share link with expiry | Large files, ongoing collaboration | Defaults to "anyone with the link", easy to forget to revoke | | Transfer service (WeTransfer and similar) | Big one-off deliveries | The file sits on their servers until expiry; previews and scanners can fetch it | | One-time secret link with attachment | Credentials, certificates, keys, contracts, anything small and sensitive | Size limits; the recipient gets exactly one chance to download |
Cloud storage is right when people will keep working on the file. Set an expiry, restrict to named accounts when the platform allows, and put a reminder in to revoke the share.
Transfer services handle size well. Check whether the service encrypts in a way that keeps it from reading the file, and remember that link scanners in corporate mail systems will often fetch the download page.
A one-time secret link is the tool for the small, sensitive file: a certificate and its key, a config file full of credentials, a signed contract, a CSV of personal data a contractor needs for one task. LinkPilot encrypts the file in your browser before upload, stores only the ciphertext, and deletes it the first time it is downloaded.
How to create a temporary secure file link in LinkPilot
File attachments are available on secret links created from a LinkPilot account. Sign in, open Secret Links and choose New.
- Attach the file. Up to three files per secret, 9 MB each. Each file is encrypted in your browser with a key derived from the secret's own key, so the server never sees the plain file.
- Add a note in the text field if the recipient needs context, such as which environment a config belongs to. Keep usernames and hostnames out of it if the file is a credential; send those separately.
- Set the expiry. One hour, 24 hours or seven days on every plan. Pro accounts can set an exact date and time.
- Set the view limit. One for a single recipient. Three, five or ten exist for the rare case where a small group must each download it.
- Add a passphrase on Pro if the link will travel through a shared channel, and pass the passphrase on by a different route.
- Create the link and send it to a recipient you have verified, with one line about what it is and when it expires.
- Check the status afterwards. The secret shows as revealed once it has been opened. Pro accounts get an audit timeline with the time of each event. If it shows as opened before the recipient got to it, treat the file as exposed.
If the handoff is just text, the free secret link tool does the same job with no account. For a plain URL that should stop working after a date, the expiring link generator is the right tool, but note that it only stops redirecting. It does not destroy anything, which is the difference explained in expiring links: the secret is destroyed, not just redirected.
Using a secret sharing tool with file attachments safely
The tool handles encryption and deletion. The remaining risks are about the file and the delivery, and they are the same for any secret sharing tool with file attachments.
Prepare the file. Open it and check that it contains only what the recipient needs. Spreadsheets carry hidden sheets, documents carry tracked changes and comments, and images and PDFs carry metadata. Export a clean copy rather than sending the working file.
Scan it. An encrypted link delivers a malicious file just as well as a clean one. Run anything that came from outside through your normal scanner before you upload it.
Verify the recipient by a second channel. A link that burns on first open protects you from copies lying around. It does not protect you from sending it to the wrong person, and once they open it the file is theirs.
Keep the link out of group channels. A link in a channel of forty people is a link forty people can open, and the first one to click it burns it for the person who needed it.
Send the passphrase separately if you set one. Link and passphrase in the same message is one message to leak.
Test with a harmless file first if your team is new to the tool. Check the upload limit, the download experience, and what happens when the link is opened twice.
After the file has been sent
- Revoke a link that was never opened once it is no longer needed. Expiry will do it eventually; revoking does it now.
- Rotate anything inside the file that is a credential, if there is any doubt about who opened it.
- Keep the record, not the file. For audited work, note who received what and when. The one-time link means you cannot go back for the file later, which is the point.
A temporary link is only as safe as the decisions around it: the right kind of link for the file, a verified recipient, a short window, and a clean file. Get those right and the tool does the rest.