An Easy Way to Add Watermarks to Your Notes and Track Leaks
Let’s say you need to send a private message to a group of people, but you are afraid that one of them will leak the message elsewhere, and you will not know who exactly. Fast Forward Labs offers a turnkey solution that identifies anyone who publicly copies and pastes your message without letting them know they’ve been caught.
Identify the elements of your note that might change unnoticed by everyone: whether you use double or single quotes; whether you write numbers like three or use numbers like 3 ; whether you use a semicolon or a comma in the list. The thinner the difference, the better. If you want to get a little more tricky, you can replace certain letters with similar Unicode characters , but as FF Labs points out, these special characters can be displayed if the message is converted to plain text.
Now, instead of sending BCC to everyone in one email, send each recipient their own BCC. As long as your recipients are used to receiving group messages through Bcc, they won’t notice the difference. In each BCC, make different subtle changes. FF Labs suggests combining different changes to increase the number of possible unique messages: one recipient gets “three”; one gets “3”; one gets a three; everyone gets a “3”.
Now, if someone discloses your message to the general public, you can compare it to your outgoing emails and identify the author. If your changes are subtle enough, they may never know how you caught them.