iDphi

Greek Aeneas Tacticus or Aeneas Stymphalian, quoted in the text " Steganography or cryptography ... (2 of n) " is really an interesting source about steganography.

In his book " The Poliorcetique - How to survive under siege ** ", he describes a series of methods that can be used to send " secret " messages. Its " Chapter XXXI - Secret letters " put together 23 paragraphs.

Among the first 12 paragraphs, we can pick up some ways listed by the strategist general as " the safest to imitate " for " the letters to be send in secret ".

Chosen extracts :

(2) Among a shipment of different things, you include a book in which " made points on the letters " that the recepient will find to compose the message.

(3) You can also, in a simple letter about anything, mark the letters to gather. Only for short messages of course.

(4) You send a man wearing shoes in which you have hidden the message ... during his sleep. Two rules to observe : write the message " on white lead that was beaten very thin " and take the most of the messenger's sleep to " unpick his shoe (...) substitute the reply (and ...) mend the shoe ( ...), taking care that the seams are done so that nothing appears. "

(5) To send a letter to Ephesus (one of the oldest Greek cities of Asia Minor, Efes in modern Turkey), one tied it to an ulcer that the messenger had on his leg.

(--) Other means are to write messages on lead plates that are inserted into the earrings hanging from the ears of women or hide the letter in the horse's bridle.

(10) Aeneas Tacticus also wrote : " Dry a bladder the size needed. After having swollen it and well bind it to its neck, write on it with ink to which you have added some gum. When the letters are dry, deflate the bladder and insert it in a bottle; after that, fill the bladder with oil, it will perfectly fit inside the bottle; then cut what overflows the bottle, do it so closely at the neck that nothing can be noticed so that it will only appear as if it contains only oil ".

(12) In short, this means is the use of invisible ink, a method that will know important developments over the centuries. The naturalist Pliny the Elder described a first formula with lemon and vinegar in his " Naturalis Historia " in the year 73. In 2011, the C.I.A. reveals the formulas developed by the Germans during the Great War of 1914-1918 to obtain invisible ink ... really invisible.

Extracts of the following paragraphs of "The Poliorcetique" in " Steganography cryptography or ... (4 of n) "

** Aeneas Tacticus, Poliorcetique - How to survive under siege, year 73; French translation of Count Beausobre in : Albert de Rochas, Mémoires de la Société d'émulation du Doubs, France - Besançon - Doubs, 4ème série, 6ème volume, Traités didactiques, 2ème partie, 1870-1871, pp 301-325; English adaptation of Pierre P. Dubois