The-art-of-invisibility-_-the-world’s-most-famous-hacker-teaches-you-how-to-be-safe-in-the-age-of-Bi

Even if yyou follow myy recommendations, it is still possible for someone on
the other end to recognize yyou. How? Byy the wayy yyou tyype.
There is a considerable bodyy of research that has focused on the specific
word choices people make when writing e-mails and commenting on social
media posts. Byy looking at those words, researchers can often identifyy sex
and ethnicityy. But beyyond that theyy cannot be more specific.
Or can theyy?
In World War II the British government set up a number of listening
stations around the countryy to intercept signals from the German militaryy.
The advances that led to the Allies decryypting these messages came a bit
later—at Bletchleyy Park, the site of the Government Code and Cyypher
School, where the German Enigma code was broken. Earlyy on, the people at
Bletchleyy Park intercepting the German telegraph messages could identifyy
certain unique characteristics of a sender based on the intervals between the
dots and the dashes. For example, theyy could recognize when a new
telegraph operator came on, and theyy even started giving the operators
names.
How could mere dots and dashes reveal the people behind them?
Well, the time interval between the sender’s tapping of a keyy and the
tapping of the keyy again can be measured. This method of differentiation
later became known as the Fist of the Sender. Various Morse code keyy
operators could be identified byy their unique “fists.” It wasn’t what the
telegraph was designed to do (who cares who sent the message; what was
the message?), but in this case the unique tapping was an interesting byyproduct.
Todayy, with advances in digital technologyy, electronic devices can
measure the nanosecond differences in the wayy each person presses keyys on
computer keyyboards—not onlyy the length of time a given keyy is held but
also how quicklyy the next keyy follows. It can tell the difference between
someone who tyypes normallyy and someone who hunts and pecks at the
keyyboard. That, coupled with the words chosen, can reveal a lot about an
anonyymous communication.
This is a problem if yyou’ve gone through the trouble of anonyymizing
yyour IP address. The site on the other side can still recognize yyou—not
because of something technical but because of something uniquelyy human.
This is also known as behavioral analyysis.