STEGANOGRAPHY- An Art of Hiding Digital Information

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Group Members:

Divya Singhvi- WRO0443467Sri Sharma- WRO0442354

Center Name: RVG, Andheri

Batch Timing: 3 to 6

Batch Commencement Date: 25thJune 2013

Group Leader

Name:

Contact Number:


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STEGANOGRAPHY- AnArt of hiding digital

information.


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We chose this topic because when we were

taught Digital Signature in class, we found

encryption and decryption to be a really

interesting topic. Hence we chose

steganography as the topic for ourassignment as it would allow us to learn

more about the whole process.


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Introduction

The word Steganography is derivedfrom two Greek words Steganos

Grahpei.

It means Concealed Writing

It is the art of hiding messages in such

a way that no one but the sender and

the intended recipient knows about thevery existence of the message.

It is different from cryptography.


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Objectives of Steganography

Cryptography the science of writing

in secret codes cryptography does

not always provide safe

communication.

Steganographyis the science of hiding

information. Its goal is to hide the

data from a third party.


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Example of a coded text-

Apparently Neutrals protest is

thoroughly discounted and ignored.

Isman hard hit. Blockade issue affects

pretext for embargo onby-products,ejecting suet and vegetable oil.

Contains a coded message-

Pershing sails from NY June 1


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The steganographic process:

Cover Medium Hidden data Stego Key

Stego Medium


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Steganography primarily uses threemediums for hiding information i.e.

Text, Image and AudioA. Text-

1. Line Shift Coding- Shifted vertically,

most visible but difficult to cipher2. Word Shift Coding- Shiftedhorizontally, very difficult to detect.

3. Feature Coding- Certain letters orcharacters are altered, horizontally orvertically.


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B. Image-

1. Images are used as they can hide

large amounts of data.2. Three methods of hiding data is Least

Significant bit, Masking and filtering

data, and algorithms &transformations

a. LSB- Takes the two least significantbits and replaces it with data, it is

the most detectable method as thecolor of the image changes


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b. Masking and Filtering- a pattern of bits

in inserted into an image to identify the

author, rights etc. Steganographyconceals this information, watermarking

scatters the bit so that it cannot be

manipulated

c. Algorithms & transformation-

Transmitting narrowband signal over a

larger bandwidth so that the spectral

density looks like its noise or change

luminance or divide bandwidth into

many sections.


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C. Audio-

Low bit encoding method is used to

hide information inside audio fileswhich is somewhat similar to LSB thatis generally used in Images.

Spread Spectrum is another methodused to conceal information inside ofan audio file. This method works byadding random noises to the signal the

information is concealed inside acarrier and spread across thefrequency spectrum.


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Echo Data Hiding

It is yet another method of hiding

information inside an audio file.This method uses the echoes in sound files

in order to try and hide information.

By simply adding extra sound to an echoinside an audio file, information can be

concealed. The thing that makes this

method of concealing information inside ofaudio files better than other methods is

that it can actually improve the sound of

the audio inside an audio file.


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Advantages

The advantage of using steganographyis to conceal information. With the useof steganography and encryption,corporations, governments, and law

enforcement agencies can communicatesecretly.

Encryption protects data and can bedetected; the only thing missing is thesecret key for decryption.Steganography is harder to detect undertraditional traffic-pattern analysis.


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Disadvantages

One of the biggest disadvantages is that quite

frequently the size of a stegnated image is

usually larger that the original image. There

can be colour changes, especially evident if

well-know images are chosen as thesteganographic cover. Images can be

degraded when trying to analyze them.

Text messages are limited in size for thehiding of data. They need redundant data to

replace a secret message. Thus changing the

type of the format or replacing the readable

text can alter text messages.


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Disadvantages

Some Internet firewalls can detect

steganographic messages. As this

technology evolves detecting

steganographic messages can be adrawback because an important

message may be deleted or

quarantined and this message may bethe one that will save a country.


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Legitimate Uses

Digital Watermarking: Prevent illegalmodification, copying, distribution.

Used to hide the existence of

sensitive files on storage media.

Illegitimate Uses

Corporate Espionage: Theft of trade secretsTerrorism


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Conclusion

Though steganography is not

implemented in wider ways but it can

be the best security tool.

The main problem of today's world is

to secure their data confidentially, the

techniques used currently are not

considered the best which can only bereplaced by Steganography.


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Bibliography

http://citeseerx.ist.psu.edu/viewdoc/downloa

d?doi=10.1.1.9.9717&rep=rep1&type=pdf

http://www.slideshare.net/
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.9.9717&rep=rep1&type=pdfhttp://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.9.9717&rep=rep1&type=pdfhttp://www.slideshare.net/http://www.slideshare.net/http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.9.9717&rep=rep1&type=pdfhttp://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.9.9717&rep=rep1&type=pdf

STEGANOGRAPHY- An Art of Hiding Digital Information

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