"A man is crazy who writes a secrete
in any other way than one which
will conceal it from the vulgar."
Roger Bacon (~1250 AD)
The essence of human communication is not only the social behavior to give or get messages (of whatever meaning) but also how to give and get them, and to include certain people by excluding others from the process of informing.
e.g. whispering is an effective way of talking to exclude the majority.
What about ways of writing?
Already some of the first written messages in human history obviously found special forms of hiding contents from the so-called others. When the knowledge of writing meant a privilege in a stronger sense as it is true today (in China for a long period writing was forbidden to people not working for the government), the alphabet itself was a kind of cryptography (that is why Catholic churches were painted with pictures explaining the stories of the Bible).
Certainly the methods of deciphering and enciphering improved a lot during the last 4.000 years. In the meantime cryptography has become a topic without end and with less technological limits every day. On the one hand there is the field of biometrics, which is highly related to cryptography but still in its beginnings, on the other hand there emerge so-called infowars, which intend to substitute or at least accompany war and are unthinkable without cryptography.
But there is much more to detect, like the different forms of de- and encoding. And very important, too, there is the history of cryptography that tells us about the basics to make it easier to understand today's issues.
In the actual age of (dis-)information storing and transporting electronic information safely increases its importance. Governments, institutions, economy and individuals rely on the hope that no-one can read or falsify their messages/data as it is much more difficult to detect and proof abuses in electronic media than in elder forms of written communication.
TEXTBLOCK 1/1 // URL: http://world-information.org/wio/infostructure/100437611776/100438658802
Aeneas Tacitus, a Greek military scientist and cryptographer, invented an optical communication system that combines water and beacon telegraphy. Torches indicated the beginnings and the ends of message transmissions while water jars were used to transmit the messages. These jars had a plugged standard-size hole drilled on the bottom side and were filled with water. As those who sent and those who received the message unplugged the jars simultaneously, the water drained out. Because the transmitted messages corresponded to water levels, the sender indicated by torch signal that the appropriate water level has been reached. It is a disadvantage that the possible messages are restricted to a given code, but as this system was mainly used for military purposes, this was offset by the advantage that it was almost impossible for outsiders to understand these messages unless they possessed the codebook.
With communication separated from transportation, the distant became near.
Tacitus' telegraph system was very fast and not excelled until
For further information see Joanne Chang & Anna Soellner, Decoding Device,