30-08-2014, 10:21 AM
Steganography
And
Digital Watermarking
Steganography.pptx (Size: 144.93 KB / Downloads: 10)
MEANING AND EVOLUTION OF STEGANOGRAPHY
Steganography is derived from the Greek for covered writing and essentially means “to hide in plain sight”.
One of the earliest uses of steganography was documented in Histories. Herodotus tells how around 440 B.C. Histiaeus shaved the head of his most trusted slave and tattooed it with a message which disappeared after the hair had regrown.
During the American Revolution, invisible ink which would glow over a flame was used by both the British and Americans to communicate secretly
A message sent by a German spy during World War II read: “Apparently neutral’s protest is thoroughly discounted and ignored. Isman hard hit. Blockade issue affects for pretext embargo on by-products, ejecting suets and vegetable oils.” By taking the second letter of every word the hidden message “Pershing sails for NY June 1” can be retrieved.
DIFFERENCE BETWEEN STEGANOGRAPHY AND ENCRYPTION
Steganography and encryption are both used to ensure data confidentiality. However the main difference between them is that with encryption anybody can see that both parties are communicating in secret. Steganography hides the existence of a secret message and in the best case nobody can see that both parties are communicating in secret.