Secure Links
Download links that can't be guessed.
Every tracked link carries a random 24-character token instead of a file number, so nobody can count their way through your files.
The problem
Numbered links give the game away.
Before
Sequential numbers
?sdt_download=1 ?sdt_download=2 ?sdt_download=3 ...
Anyone could try 1, 2, 3 and fetch every registered file, including ones you hadn’t published yet.
Now
Random tokens
?sdt_download=6f3a9c1e84b27d05a1c4e9f2
Each file gets a random 24-character token (96 bits). There’s no sequence to follow and nothing to guess.
A token for every file
New files get a token when they’re created. Existing files were given one automatically when the feature arrived.
Unpublished stays hidden
A file that isn’t published behaves exactly like one that doesn’t exist, so a link never reveals that a file is waiting.
Old links, your call
Numeric links from before the upgrade keep working until you retire them, so nothing breaks overnight.
Retiring old links
Switch off numbered links when you're ready.
The file numbers that existed at the upgrade are listed in the sdt_legacy_numeric_ids option. Remove a number and its old link stops working.
- Replace any old links in pages, settings and emails with the token link from the File Downloads table
- Remove those file numbers from the option
- Files added after the upgrade only ever have token links
For example, with WP-CLI, to keep only files 1 and 6:
wp option update sdt_legacy_numeric_ids "1,6"
What a token doesn't do
The token protects the tracked link, not the file itself. If a file sits in a public folder such as /wp-content/uploads/, anyone who knows its direct address can still download it, and that download isn’t counted.
If a file must stay private, block direct access to its folder in your web server settings. Files on your own site are streamed through WordPress, so the tracked link keeps working. For files on external storage, protect their address with your storage provider.
Links you can share with confidence.
Secure tokens come built in. There’s nothing to switch on.