Unbroken Codes

Throughout history, especially in the last century, codes have fascinated encryption specialists and the average person. Queen Elizabeth I used a spy network who worked with secret codes. Wired Magazine often has some fascinating articles on topics of interest, including the article here about 7 unbroken codes in history. One of those that has fascinated people and criminologists since the 1970s is the code the Zodiac serial killer used. An example of the code is following.
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