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ECrime and Steganography Lecture & Demonstration.

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Presentation on theme: "ECrime and Steganography Lecture & Demonstration."— Presentation transcript:

1 eCrime and Steganography Lecture & Demonstration

2

3 © WetStone Technologies, Inc. Origins of Steganography Steganography Origins – From the Greek Roots Steganos or Covered Graphie or Writing Covered Writing – First Known Usage The early Greeks and Persians used several forms of covered writing to conceal the communication of secret or covert messages Origins date back as far 2,500 years ago

4 © WetStone Technologies, Inc. Origins of Steganography Demaratus of Ariston was exiled in Persia, and while there, he received news that Xerxes had decided to invade Greece. He decided that he must get word of the pending invasion to Sparta. Since discovery of such an act meant certain death, he decided that he must conceal the message. He scraped the wax off a pair of wooden folding writing tablets and carved a warning message in the wood. He then covered the wood with a fresh coat of wax. The tablet was passed by the sentries without raising any suspicion and was delivered to and read by the Greeks. WAX TABLET

5 © WetStone Technologies, Inc. Origins of Steganography Null Cipher Messages – Most notably this method was used during World War I by the Germans – Text based steganography has taken on several forms PRESIDENTS EMBARGO RULING SHOULD HAVE IMMEDIATE NOTICE. GRAVE SITUATION AFFECTING INTERNATIONAL LAW, STATEMENT FORESHADOWS RUIN OF MANY NEUTRALS. YELLOW JOURNALS UNIFYING NATIONAL EXCITEMENT IMMENSELY PERSHING SAILS FROM NY JUNE 1

6 © WetStone Technologies, Inc. Dangers of Steganography Steganography vs. Encryption – Steganography and Encryption each have distinct purposes Encryption – Keeps information private by using a mathematical algorithm which renders the contents unreadable unless you possess a specific key allowing you to decipher the message – Encrypted objects are typically easy to identify or detect – The existence of the message is obvious, however the content is obscured Steganography – Hides the actual existence of a message or hidden data – Hides information in plain sight by exploiting weaknesses of our human senses

7 © WetStone Technologies, Inc. Dangers of Steganography Steganography Encryption

8 Steganography Communication Covert Message Send Message With Innocuous Attachment Firewall RevealStego CP Carrier Image ApplyStego Revealed CP password

9 © WetStone Technologies, Inc. Who knows about this technology?

10 © WetStone Technologies, Inc. How big is the problem?

11 © WetStone Technologies, Inc. Who knows about it? source google.com

12 © WetStone Technologies, Inc. How global is the problem? ARABICARABIC

13 © WetStone Technologies, Inc. How global is the problem? CHINESECHINESE

14 © WetStone Technologies, Inc. How global is the problem? GERMANGERMAN

15 © WetStone Technologies, Inc. How global is the problem? KOREANKOREAN

16 © WetStone Technologies, Inc. How global is the problem? CROATIANCROATIAN

17 © WetStone Technologies, Inc. How global is the problem? JAPANESEJAPANESE

18 Steganography How does it work?

19 © WetStone Technologies, Inc. How is this possible? Human Sight – Characteristics Poor detection and identification of differing shades of color Poor recognition of high intensity shades (i.e. bright blue and violet shades of color) Human Hearing – Characteristics Very sensitive to noise and distortion Imperceptible in detecting slight amplitude shifts Imperceptible in detecting slight phase shifts

20 © WetStone Technologies, Inc. Palette Images Map to a pre-defined color on a table – Pixel represented by table lookup value 2 2

21 © WetStone Technologies, Inc. RGB or True Color Images True Color images – Typically represented by 24 bits – 8 bits for each color (red, green, blue) – 16.7M possible colors (2 8 x 2 8 x 2 8 ) – Each pixel holds color triplet 4 4

22 Least Significant Bit (LSB) Steganography Applied to RGB Color Images

23 © WetStone Technologies, Inc. LSB Substitution – bit RED GREEN BLUE Before After Combined Color Individual Colors After LSB Substitution

24 © WetStone Technologies, Inc. LSB Substitution bit 0 and RED GREEN BLUE Before After Combined Color Individual Colors After LSB Substitution

25 © WetStone Technologies, Inc. LSB Substitution bits (0-3) RED GREEN BLUE Before After Combined Color Individual Colors After LSB Substitution

26 © WetStone Technologies, Inc. Visual Analysis

27 © WetStone Technologies, Inc. Visual Analysis

28 © WetStone Technologies, Inc. Visual Analysis

29 © WetStone Technologies, Inc. Digital Audio CD Audio – Typically referred to as wave audio files – Wave audio is an uncompressed set of samples – Each samples is represented as a16-bit value Binary – – Hex – FFFF Decimal – to – Each sample is collected at a frequency of 44.1 Khz or 44,100 times per second based on Nyquists theorem Nyquist's theorem: A theorem, developed by H. Nyquist, which states that an analog signal waveform may be uniquely reconstructed, without error, from samples taken at equal time intervals. The sampling rate must be equal to, or greater than, twice the highest frequency component in the analog signalanalog signal waveformerrortimesampling ratefrequency component Nyquist's theorem: A theorem, developed by H. Nyquist, which states that an analog signal waveform may be uniquely reconstructed, without error, from samples taken at equal time intervals. The sampling rate must be equal to, or greater than, twice the highest frequency component in the analog signalanalog signal waveformerrortimesampling ratefrequency component 5 5

30 © WetStone Technologies, Inc. Digital Audio - Dangers Audio based steganography has the potential to conceal more information – Audio files are generally larger than images – Our hearing can be easily fooled – Slight changes in amplitude can store vast amounts of information Many sources and types makes statistical analysis more difficult – Greater amounts of information can be embedded without audible degradation

31 © WetStone Technologies, Inc. LSB in Action Steganography Demonstration

32 © WetStone Technologies, Inc. Known Methods of Steganography Data Appending Covert Channels Formatting Modification Word Substitution Color Palette Modification Encoding Algorithm Modification 24-Bit LSB Encoding

33 © WetStone Technologies, Inc. Known Methods of Steganography Typically modifies the cover file by appending data after the standard end-of-file marker Data Appending Example Program Camouflage

34 © WetStone Technologies, Inc. Data Appending Example Carrier Image Hidden Data

35 © WetStone Technologies, Inc. Data Appending Example Original Carrier File Camouflage Hidden Message End of File MarkersHidden Data

36 Camouflage in Action Demonstration

37 © WetStone Technologies, Inc. Known Methods of Steganography Formatting Modification Example Program Invisible Secrets Works by making subtle modification to text and/or line spacing in standard documents

38 © WetStone Technologies, Inc. Formatting Modification Example Carrier File Hidden Data

39 © WetStone Technologies, Inc. Formatting Modification Example Original Carrier File Modified Carrier File HASH D350 E B D1A4 2FDB 6A54 6C34 2F94 DE8F 89E5 HASH 7E62 FC70 65FE DC 697D CBDF EEEC 3E07

40 © WetStone Technologies, Inc. Formatting Modification Example Original Carrier FileModified Carrier File

41 © WetStone Technologies, Inc. Known Methods of Steganography Word Substitution Spam Mimic – Web based steganography tool Automatically create spam like messages that actually contain hidden data

42 © WetStone Technologies, Inc. Word Substitution Example Message to Encode

43 © WetStone Technologies, Inc. Spam mimic Spam encoded message

44 © WetStone Technologies, Inc. Spam mimic

45 © WetStone Technologies, Inc. Spam mimic

46 © WetStone Technologies, Inc. Known Methods of Steganography Typically applied to 8-BIT images such as GIF or 8 BIT BMP files. The technique modifies the color palette and the associated colors in the image to embed data Color Palette Modification Example Program Gif-it-Up

47 © WetStone Technologies, Inc. Color Palette Modification Example Carrier Image Hidden Data

48 © WetStone Technologies, Inc. Color Palette Modification Example Carrier Image Covert Message

49 © WetStone Technologies, Inc. Known Methods of Steganography 24-Bit LSB Encoding Example Program The LSB method makes subtle changes to each pixel of the image. The changes are undetectable through visual inspection for most images Example Program : S-Tools Version 4.0

50 © WetStone Technologies, Inc. Known Methods of Steganography Encoding Algorithm Modification JPEG Discrete Cosine Transform (DCT) Modification MP3 perceptual noise shaping (PNS) Modification

51 © WetStone Technologies, Inc. Known Methods of Steganography Most typically applied to JPEG files. LSB modifications are made to the coefficients of the Discrete Cosine Transform prior to the lossless stage of compression DCT Coefficient Modification Example Program JPHS

52 © WetStone Technologies, Inc. DCT Coefficient Modification Example Carrier Image Hidden Data

53 © WetStone Technologies, Inc. Carrier Image HASH 7847 C7B B350 17E B315 27B1 8ABE File Size 224,186 Modified Carrier Image HASH 4AC7 2ADA 5C95 08A3 645A 8FC2 30CD 3AA5 E D File Size 223,122 DCT Coefficient Modification Example

54 © WetStone Technologies, Inc. DCT Formula 8 x 8 2D Forward DCT 8 x 8 2D Inverse DCT

55 © WetStone Technologies, Inc. Quantized DCT LOW ENERGY MEDIUM ENERGY HIGH ENERGY

56 © WetStone Technologies, Inc. Known Methods of Steganography Modification of the MP3 encoding algorithm to insert data without altering the sound quality MP3 PNS Modification Example Program MP3 Steno

57 © WetStone Technologies, Inc. Known Methods of Steganography A modified communication channel exploited by a sender and receiver to exchange information Covert Channels Example Program Covert TCP Source code supplied with informational article published in First Monday nd/index.html#app

58 © WetStone Technologies, Inc. Covert Channels Example Manipulation of the Initial Sequence Number Field* – The Initial Sequence Number is used to establish a communication link between a client and remote server – A program can be created to generate this number using a constant divided by an ASCII character value – A similar program on the other end can passively listen for communication and then decode the message *http://www.firstmonday.dk/issues/issue2_5/rowland/index.html#app

59 © WetStone Technologies, Inc. Covert Channels Example 20:30: > : S : (0) win 512 (ttl 64, id 49408) Packet Header 20:30: Time Stamp Source : ISN > S Destination Win 512 (ttl 64, id 49408) Misc. Fields

60 © WetStone Technologies, Inc. Covert Channels Example : Locate ISN / = 72 Divide by constant 72 = H in ASCII Convert to ASCII

61 Steganography Investigation Demonstration

62 © WetStone Technologies, Inc. Summary Steganography weapons are easy to use, and readily available to our adversaries

63 © WetStone Technologies, Inc. Summary Steganography is capable of concealing the mere existence of incriminating information and/or covert communications

64 © WetStone Technologies, Inc. Summary Steganography provides criminals with the ability to: Conceal incriminating information Covertly communicate with accomplices Innocuously share dangerous information

65 © WetStone Technologies, Inc. Summary Steganography is difficult to: Detect Analyze Break

66 © WetStone Technologies, Inc. Summary Modern digital steganography is capable of innocuously concealing or transferring large amounts of information. A rule of thumb is 30-40% of the carrier size.

67 © WetStone Technologies, Inc. Summary When used in conjunction with the Internet, steganography becomes a globally effective weapon for criminals and terrorists.

68 Thank You Chet Hosmer CEO & Chief Scientist


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