Red herring...

In literature, a red herring is a narrative element intended to distract the reader from a more important event in the plot, usually a twist ending.



The term "red herring" originates from the tradition whereby young hunting dogs in Britain were trained to follow a scent with the use of a "red" (salted and smoked) herring (see kipper). This pungent fish would be dragged across a trail until the puppy learned to follow the scent. Later, when the dog was being trained to follow the faint odor of a fox or a badger, the trainer would drag a red herring (which has a much stronger odor) across the animal's trail at right angles. The dog would eventually learn to follow the original scent rather than the stronger scent.

In literature, the most commonplace use of a "red herring" is in mystery fiction. One particular character is described or emphasized in a way that seems to throw suspicion upon that character as the person who committed the crime: later, it develops that someone else is the guilty party.

This is used in cryptography as well!

In cryptography, a red herring is a second hidden message that is intended to be discovered more easily so that the real message remains hidden to anyone who might intercept the transmission and break the red herring code. Only the intended receiver would know the key to unlocking the real message.