1

Adnan GutubComputer Engineering

King Fahd University of Petroleum & Minerals

Saudi Arabia

A Novel Arabic Text Steganography Method Using Letter Points & Extensions

2

Arabic Diacritics Arabic Diacritics حركاتحركات Based Based Steganography Steganography Steganography is the ability of hiding information in redundant bits of any unremarkable cover media.

This presentation will discuss new Arabic text steganography schemes.

3

4

Difficulties of Text Difficulties of Text SteganographySteganographyIn steganography, the cover media used to hide the message can be text, image, video or audio files.

Using text media for this purpose is considered the hardest !

Text data does not have much needless information within the essential data.

Fig. 1: Data Hiding in Binary Text Documents

5

Previous TechniquesPrevious Techniques

Many techniques have been proposed for text steganography that are mostly graphical in nature:

1.Line shifting:•Text is divided into lines.

•Implementing 1 is by shifting the line a small fraction that can’t be detected by the bare eye.

•Implementing a 0 means keeping the line as is.

2.Word shifting:

•Same as previous but text is divided into words.

3. Word horizontal shifting:• Same as previous approach

but words are shifted left and right to indicate bits.

Original Text: We are embedding a ‘b’ using horizontal word shifting.

Modified Text: We are embedding a ‘b’ using horizontal word shifting.

Hiding ‘b’ = 0x62 = 0 1 1 0 0 0 1 0b

Original Text: We are embedding a ‘b’ using horizontal word shifting.

Modified Text: We are embedding a ‘b’ using horizontal word shifting.

Hiding ‘b’ = 0x62 = 0 1 1 0 0 0 1 0b

4. White space manipulation:• White spaces at the end of the

line are not apparent.

5. HTML formatting:• HTML syntax is case

insensitive. This can be used to hide information.

6

phgloji

m

ei

ss

un

afyn e

i

r sn

r

Apparently neutral’s protest is thoroughly discounted and ignored. Isman hard hit. Blockade issue affects pretext for embargo on by-products, ejecting suets and vegetable oils.

7

phgloji

m

ei

ss

un

afyn e

i

r sn

r

8

Previous TechniquesPrevious Techniques

• Other variations for the previous techniques are proposed.

• Pointed letters shifting.

• Some approaches consider the syntactic structure of the language used.

• ‘Run’ can be used instead of ‘sprint’ to mean something.

• In summary the previous techniques tackle one of two areas:

• Limitations of human sight.

• Specific language grammar.

9

10

Arabic Based SteganographyArabic Based Steganography

Arabic language is the largest living member of the Semitic language family in terms of speakers. (270 million speakers).

It contains 28 alphabet characters; 15 of which have points.

IُةKَغM MَغKُةIالٌّل الٌّل

Characters with no points

Characters with one

point

Characters with two points

Characters with three

points

أ ح د ر س ص ط ع ك ل م هـ و

ب ج خ ذ ز ض ظ غ ف ن

ت ق ي ث ش

Fig. 2: Arabic Alphabet

11

Pointed Letters (Special for Arabic) Shirali-Shahreza, 2006

Drawback: robustness

un-pointed letters

pointed letters

ر د ح اص سك ع طهـ م ل

و

ت بخ ج ثش ز ذظ ض

ق ف غي ن

12

13

Pointed Letters & Extensions

adding extensions after pointed letters.

يعنيه ماال تركه المرء اسالم حسن من

1011

ت المرء اسالم حسن ي ـمن ماال هـعنيـركه

101 1

14

Pointed Letters & Extensions

adding extensions before pointed letters.

يعنيه ماال تركه المرء اسالم حسن من

1011

حس ـم يعن ـن ماال تركه المرء اسالم يهـن

10 1 1

15

16

EvaluationEvaluation

Approach p q r (p+r+q)/2

Dots 0.2764 0.4313 0.0300 0.3689

Extension-Before 0.2757 0.4296 0.0298 0.3676

Extension-After 0.1880 0.2204 0.0028 0.20561616

File Type File Size (Bytes) Cover Size (Bytes) Capacity (%)

.txt 4439 365181 1.215 %

.html 4439 378589 1.172 %

.cpp 10127 799577 1.266 %

.gif 188 15112 1.244 %

Average 1.22 %

17

ConclusionConclusion

The text and image approaches are discussed which The text and image approaches are discussed which are used to hide information in Arabic diacritics for are used to hide information in Arabic diacritics for steganographic.steganographic.

This paper presents a variety of scenarios that may This paper presents a variety of scenarios that may achieve up to arbitrary capacities. Sometimes achieve up to arbitrary capacities. Sometimes tradeoffs between tradeoffs between capacity, securitycapacity, security and and robustnessrobustness imply that a particular scenario should be chosen. imply that a particular scenario should be chosen.

The overhead of The overhead of Kashidah suffers from restrictions on Kashidah suffers from restrictions on its insertion especially the need of dotted character.its insertion especially the need of dotted character.

1717

18

Summary

Steganography has its place in the security. On its own, it won’t serve much but when used as a layer of cryptography, it would lead to a greater security.

Far fetched applications in privacy protection and intellectual property rights protection.

Research is going on in both the directions One is how to incorporate hidden or visible copyright

information in various media, which would be published.

At the same time, in opposite direction, researcher are working on how to detect the trafficking of illicit material & covert messages published by certain outlawed groups.