Governments have always been plagued by document leaks. Now Sun Microsystems
of Mountain View, California, has come up with a way to identify the culprits
(EP 798 619).
The technique can identify the source of the document if it has been
photocopied, or scanned with optical character recognition. It even works if the
document has been retyped.
Each authorised recipient of the document is assigned a number in binary
code. Sun鈥檚 coding system then analyses the text and makes minor changes to each
copy, such as leaving out a comma. These changes incorporate the unique code in
the text鈥攚ithout altering the meaning.
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If someone leaks a copy, Sun鈥檚 decoder compares the leaked document with the
master, logs the differences and works out which of the authorised copies has
been leaked.
