security and privacy issues incommmunications

8/7/2019 SECURITY AND PRIVACY ISSUES INCOMMMUNICATIONS

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SECURITY AND PRIVACY

ISSUES IN COMMUNICATIONS

INTERNAL GUIDE

Mrs. P.GAYATHRISUBMITTED

BYA.SHANTHI


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CONTENTS

y Introduction

y Cryptography

y Cryptographic algorithmsy Steganography

y Advantages and Disadvantages

y Applications

y Conclusion

y Future scope

y References


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INTRODUCTION

y Security has became a more sensible issue either it may be in

real world or in cyber world.

y

The main problem that occurred in network security aresecrecy,authentication,nonrepudiation and integrity control.

y Data security deals with security during transmission of data.

y Commonly used technologies are cryptography,steganography.

y

As the internet and other forms of electronic communicationsbecome more prevalent ,electronic security is becoming

increasingly important


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CRYPTOGRAPHY

y The art of protecting the information by transforming it into an

unreadable format ,called cipher text.

y

The wordcryptography

means secrete writing.

y Cryptography is the science of using mathematics to encrypt

and decrypt data.


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Example

y Here is a quick example of the encryption anddecryption steps involved with the simplesubstitution cipher. The text we will encrypt is'defend the east wall of the castle'.

y K

eys for the simple substitution cipher usually consistof 26 letters (compared to the caeser cipher's singlenumber). An example key is:

plain alphabet : abcdefghijklmnopqrstuvwxyz

cipher alphabet: phqgiumeaylnofdxjkrcvstzwb

An example encryption using the above key:

y plaintext : defend the east wall of the castle

y ciphertext: giuifg cei iprc tpnn du cei qprcni


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NEED OF CRYTOGRAPHY

y Confidentiality :ensuring that no one can read message expect

the intended receiver.

y

Authentication :the process of proving ones identity.y Data integrity :Only authorized parties are able to modify

computer system assets and transmitted information.

y Non-repudiation: Both the sender & receiver are unable to deny

the transmission.


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TYPES OF ALGORITHMS

y Secret key Cryptography (symmetric)

y Public key Cryptography (asymmetric)

y Hash function


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SECRET KEY CRYPTOGRAPHY

y Follows symmetric algorithms.

y Single key is used to encrypt and

decrypt.y Key must be known by both parties


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PUBLIC KEY CRYPTOGRAPHY

Follows asymmetric algorithms.

Each entity has two keys.

private key (a secret)public key (well known)

Public keys are used for encryption

Private keys are used for decryption


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HASH FUNCTION

y Hash function also called message digest &one way

encryption, are algorithms that in one sense use no key. Instead

a fixed hash value is computed based upon the plain text that

makes it possible for either the contents or length of plain text

to be recovered.

y Hash function is easy to compute.


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STEGANOGRAPHY

y Steganography is a art & science of hiding the fact that

communication is taking place.

y

Steganography is the practice of hiding private or sensitiveinformation within something that appears to be nothing out of

the usual.

y Steganography in the modern day sense of the word usually

refers to information or a file that has been concealed inside a

digital Picture, Video or Audio file


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TYPES OF STEGANOGRAPHY

y Secret message is hidden in different forms:


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STEGANOGRAPHY IN TEXT

y The code word is embedded in the document by altering textual

features. by applying each bit of code word to a particular

document.

y line-shift coding: lines are vertically shifted.

y word shift coding: code words are horizontally shifted.

y feature coding: coding done using certain text features.


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STEGANOGARPHY IN IMAGES

y Image Steganography has come quite far in recent years with

the development of fast,powerful graphical computers.

y

The techniques used are:1. Image compression

2. Image encoding techniques

least significant bit insertion

masking and filtering techniquestransformations


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STEGANOGRAPHY IN AUDIO

y Low bit encoding method is used to hide information inside

audio files which is similar to LSB used in images.

y

Spread spectrum is another method used to hide theinformation inside the audio file. This method works by adding

random noises to the signal information is conceal inside a

carrier and spread across the frequency spectrum.

y Echo data hiding is another method of hiding information

inside an audio file.


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STEGANOGRAPHY IN VIDEOS

y Steganography in videos is similar to that of in images, apart of

information is hidden in each frame of video.

y

When only small amount of information is hidden inside thevideo it is generally isnt noticeable at all, however more the

information that is hidden the more noticeable it will become.


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ADVANTAGES

y The main advantage is we can provide security to data with

multiple levels of security.

y

We can embed huge volumes of data with modernSteganography.

y Symmetric encryption is simple and fast.


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DISADVANTAGES

y Transmission time for documents encrypted using public key

cryptography is significantly slower then symmetric

cryptography.

y Message is hard to recover if image is subject to attacks such as

translation and rotation.

y Some data hiding methods follow the principle that the edge

area can tolerate more changes than smooth areas. this does not

differentiate the texture features from edge ones.


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APPLICATIONS

y Smart IDS

y Military applications

yBanking applications

y Companies secret data safe circulation

y ATM security

y Computer password

y Digital signatures


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CONCLUSION

The system deals with providing easy and secure files

transmissions across the network. The data is encrypted and

embedded with any container file and transmitted through the

network, at the receiving end the data is deembedded,decrypted

and displayed.

The application can now be used in any organization

that uses networks. the proposed methods achieves higher

embedding capacity and physical property.


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FUTURE SCOPE

y Crypto smart cards

y Java rings

yDNA cryptography

y Quantum cryptography


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REFERENCES

y www.cryptography.com

y www.wikipedia.com

ywww.cryptography.org

y wikipedia contributers.steganography.wikipedia

y An introduction to Steganography ,IEEE security and privacy


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THANK YOU

..


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QUERIES ?

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