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A CS 8C5588 8S PRODUCTION JONATHAN HEAD TROJAN ERDMAN MANN ETHNIC ERIC HUTCHINS URCHINS A STEPHEN PENIS LENGTH LIANG WARM PILL PORTMAN WILLS SNOT PATS STEGANOGRAPHY A HORNY EGG stegein to cover stegein STEGANOGRAPHY STEGANOGRAPHY grafein to write grafein STEGANOGRAPHY cover * message * stego STEGANOGRAPHY “Words, Words, Words” • English is redundant. • Relative message lengths: – Important Message: 13 Bytes – Spam Mail: 1,108 Bytes Dear Friend , Your email address has been submitted to us indicating your interest in our newsletter . If you no longer wish to receive our publications simply reply with a Subject: of "REMOVE" and you will immediately be removed from our club . This mail is being sent in compliance with Senate bill 2116 , Title 7 , Section 301 ! Do NOT confuse us with Internet scam artists . Why work for somebody else when you can become rich within 13 DAYS ! Have you ever noticed the baby boomers are more demanding than their parents and nobody is getting any younger ! Well, now is your chance to capitalize on this . WE will help YOU process your orders within seconds plus deliver goods right to the customer's doorstep . The best thing about our system is that it is absolutely risk free for you ! But don't believe us ! Mr Ames who resides in Delaware tried us and says "My only problem now is where to park all my cars" ! This offer is 100% legal ! If not for you then for your loved loved ones ones - act now ! Sign up a friend and you'll get a discount of 50% . Thank-you for your serious consideration of our offer ! Dear Friend , Your email address has been submitted to us indicating your interest in our newsletter . If you no longer wish to receive our publications simply reply with a Subject: of "REMOVE" and you will immediately be removed from our club . This mail is being sent in compliance with Senate bill 2116 , Title 7 , Section 301 ! Do NOT confuse us with Internet scam artists . Why work for somebody else when you can become rich within 13 DAYS ! Have you ever noticed the baby boomers are more demanding than their parents and nobody is getting any younger ! Well, now is your chance to capitalize on this . WE will help YOU process your orders within seconds plus deliver goods right to the customer's doorstep . The best thing about our system is that it is absolutely risk free for you ! But don't believe us ! Mr Ames who resides in Delaware tried us and says "My only problem now is where to park all my cars" ! This offer is 100% legal ! If not for you then for your LOVED LOVED ONES ONES - act now ! Sign up a friend and you'll get a discount of 50% . Thank-you for your serious consideration of our offer ! Give us an A- Give us an A+ www.spammimic.com The auto drives fast on a slippery road over the hill Meeting: 9 o’clock at my home Over the slope the car travels quickly on an icecovered street http://www.texthide.com/ Ones and Zeros 1’s and 0’s • Commas in lists – Guns, butter, and brownies – Guns, butter and brownies • Carriage return vs. Line feed (newline) – Carriage return: ASCII 015 – Line feed: ASCII 012 Spy Game 1’s and 0’s • Intercepted communication from German Spy in WWII Apparently p neutral’s e protest r is s h i n thoroughly discounted and ignored. Isman hard hit. g s a i r Blockade issue affects pretext l s f for on o embargo m y n by-products, ejecting suets u and n vegetable e j i oils. p h g l o j i e i s s n m u r n a f y n i r e s A Picture is Worth 1,024 Words • Images have a lot of data: – Spam Mail: 1,108 Bytes – Picture of Dave: 152 KB • Ways to hide information – Least significant bit (BMP) – Palette Shifts (GIF) – Discrete Cosine Transforms (JPG) What’s lurking behind this pretty face? Another pretty face. (And quite a body.) Another pretty face. (And quite a body.) Oops! We did it again… • Audio files contain even more data: – Spam Mail: 1,108 Bytes – Picture of Dave: 152 KB – Sneaker’s Theme: 3,466 KB • Ways to hide information – Least significant bit (RAW) – Complicated stuff we don’t understand (MP3) Detecting Steganography • Statistical properties of – – – – Text Music Images Videos • Concentrate on hiding data in a JPEG Jay-Pehg • JPEG : Joint Photographic Expert Group • Compression Algorithm 8x8 Pixel Block Discrete Cosine Transformation Quantizer Binary Encoder 100100… Discrete WHAT?! • Discrete Cosine Transform 8x8 Pixel k2 Block k1 2i 1 cos 2 j 1 B(k1 , k2 ) 4 A(i, j ) cos i 0 j 0 2 N1 2N2 N1 1 N 2 1 • Transforms 8x8 blocks into 64 DCT coefficients • FIRST coefficient is the most important 41 30 98 -6 26 18 4 2 Quantize THIS! • “Lossy” Compression • Values increase as you move down 98 -6 3 11 33 -1 4 2 9 17 0 0 DCT QUA VALUE • Quantized value = Round ( DCT / QUA ) • JPEG = Discard zeros 33 -1 JPG Binary me! • Convert to binary in a zigzag 33 -1 0 0 0100001 0000000 1000001 0000000 Hide and go seek • Where do you hide the message? Detecting Steganography http://www.citi.umich.edu/u/provos/cv.html J-Steg vs. Masker • StegDetect can find stego created in JSteg • Cannot detect stego created in Masker • StegDetect knows what to look for… – J-Steg – JPHide – Outguess – … not Masker (or anything else) The Verdict • Detecting steganographic content in any cover is hard. • Only one documented case of uncovering a “wild” stego. Secret Number 1 • Binary gesture 1000011 1010011 0110101 0111000 0111000 C S 5 8 8 Secret Number 2 Remember the music from the introduction? Policy-Directed Code Safety by David E. Evans S.B. Massachusetts Institute of Technology (1994) S.M. Massachusetts Institute of Technology (1994) Submitted to the Department of Electrical Engineering and Computer Science in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology February 2000 (C) Massachusetts Institute of Technology 1999. reserved. All rights Author...................................................... David Evans Department of Electrical Engineering and Computer Science October 19, 1999 Secret Number 3 • What the heck is up with the cups? • Absolutely nothing. The Verdict • Too many images, MP3’s, spams, pictures of David Evans on the Internet. • Too many possible algorithms. • In conlusion: too setec many astronomy secrets Special assistants Casting STARRING by to Mr. Erdman (inDavid alphabetical Whitfield Evans,Diffie C.S.A. order): Maartin Hellman SOUNDTRACK Jonathan Erdman LISTING Special assistants Eric Hutchins to Mr. Hutchins Charles Stephen “Main Title” Babbage Liang Sneakers: Original Portman Alan Motion Turing Wills Picture Soundtrack James Horner, Branford Marsalis Special assistants to Mr. Liang GUEST “1812 Ron APPEARANCES Overture” Rivest BY: Pytor Il’yich Adi Shamir Tchaikovsky The London Leonard David Symphony Evans Adleman Orchestra Royal DavidAlbert E. Evans’ Hall,face 1993 Special Britney assistants Spears’ to Body Mr. Wills Claude Shannon Martin Bishop SPECIAL “Mother” THANKS TO: