May 20, 2015
2. Table of Contents : Introduction History Past use Modern use Advantages Disadvantage Steganography vs. cryptography Conclusion Reference 3. Introduction : It is an art of hiding information into anydigital images. Only sender and receiver, suspects theexistence of the message. 4. Introduction (contd.): It is mixture of two Greek words : Steganos :- Covered or Protected Graphei :- WritingThats why called Hiding of image orinformation or covered writing In this we Combine secret image / file withcurrent image which gives the hidden image. The hidden image is difficult to detect withoutretrieval. 5. Can be hidden in digital data MS Word (doc) Web pages (html) Executables (exe) Sound files (mp3, wav,) Video files (mpeg, avi) Digital images (bmp, gif, jpg) 6. History Of Steganography : Steganographic techniques have been usedfrom ancient ages. The aim of steganographic communicationback and now, in modern applications, is thesame i.e. to hide secret data. 7. Past use : Hidden messages within wax tablets inancient Greece, people wrote messages onthe wood, then covered it with wax . 8. Past use (contd.) : Hidden messages on messengersbody also used in ancient Greece. In this the message tattooed on theshaved head. Hidden by the hair that afterwardsgrew over it, and exposed by shavingthe head again. This method has obvious drawbacks,such as delayed transmission whilewaiting for hair to grow and limitedsize also. 9. Past use (contd.) : During World War II, the French sent somemessages written on the backs of couriers usinginvisible ink. Hidden messages on paper written by secret inks,under other messages or on the blank parts ofother messages. Which was latterly retrieve byeither rays or fire , etc. 10. Past use (contd.) : Jeremiah Denton repeatedly blinked his eyes inMorse Code . During 1966 televised press conference that hewas forced into as an American POW by his NorthVietnamese captors, spelling out the word, "T-O-R-T-U-R-E. 11. Modern Use : Modern steganography entered the world in1985 when personal computer being appliedto classical steganography problems. Here we hide our secret data / messages into : Digital Images. Audio. Video , etc.Here steganography is done with the helpof Steganography tool. 12. Steganography In Images : Messages are hidden in background. May be anywhere in image. Cannot see message in image without encryption. This is done with the help of least significant bit (LSB). 13. Original Image :Encrypted Image : Hidden Image : 14. This is how modern Steganography Works.Still Problem !!!Here we go through live example with Steganography tool. 15. Advantages : Top Secret No body apart from sender andreceiver can retrieve message. Hide messages like Images , Audio , Video ,text , etc. Used by Intelligence Bureau To send theirSecret messages. 16. Disadvantages :Apart from advantages there are also disadvantage too. Used by terrorists : In 9/11 attack al-Qaeda head BinLaden used this technology. In an image he encoded whole message and thentransport it via e-mail.Lets see how he done this : 17. Not exact image .Just for example.Is it just an image ????? 18. No !!!!!This is much more than an image.It holds messages in it. 19. Steganography vs. CryptographySteganography CryptographyHide the message Does not hide messageOnly sender and receiver knows theexistence of messageEverybody knows the existence ofmessageEnd result is stego-media End result is cipher-textUsed from ancient time till modern era Used in modern era 20. Conclusion Hiding information. Secret among sender and receiver. Having both aspects i.e. good and bad use. 21. Reference http://en.wikipedia.org/wiki/Steganography http://www.webopedia.com/TERM/S/steganography.html - For definition. http://www.slideshare.net/ Steganography- A Data Hiding Technique .pdffile by - Arvind Kumar and Km. PoonaAssistant Professor Meerut (INDIA).