Cryptography by ME 2

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CRYPTOGRAPHY

Made by:-PUSHPENDRA PANDEY

B.TECH 3RD YEAR

SARASWATI INSTITUTE OF TECHNOLOGY

AND MANAGEMENT

ELECTRONICS AND COMMUNICATION

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CRYPTOGRAPHY

Cryptography,a word with greekorigins which means secret writing.

However we use the term refers toscience and art of transforming amessage to make them secure andimmune of attack.

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INTRODUCTION

Hidden writing

Increasingly used to protect information

Can ensure confidentiality

Integrity and Authenticity too

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TERMS OF CRYPTOGRAPHY

PLAIN TEXT

The original message before beingtransformed is called plain text.

CIPHER TEXT

The message after transformation is called as

cipher text. 4

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TERMS CONT

ALICE The person who sends the secure

data called alice.

BOB

The person who receives the data.

EVE The person or medium who some

how disturbs the communication

between alice and bob. 5

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CRYPTOGRAPHY MECHANISM

ENCRYPTION An encryption algorithm transform the plain

text into cipher text. it is done by sender.

DECRYPTION An decryption algorithm transform the the

cipher text back into plain text.it is done by

reciever. 6

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KEY IN CRYPTOGRAPHY

KEY A sequence or a number that controls the

operation and behavior of the cryptographicalgorithm.

TYPES OF KEY Symmetric key

Asymmetric key 7

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TYPES OF KEY

SYMMETRIC KEYS

It is also termed as secret key.

It is used by both sender and receiver. The sender uses this key and incryption

algorithm to incrypt the data.

The receiver uses decryption algorithm and

same key to decrypt the data received 8

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TYPES OF KEY

ASYMMETRIC KEY These are of two types

Private key

Public key

Private key is kept by receiver.

Public key is announced to the public.

Public key is used for encryption is different

from the private key that is used for decryption 9

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PURPOSE OF CRYPTOGRAPHY IN

NETWORK SECURITY

AUTHENTICITY PRIVACY/CONFIDENTIALITY INTEGRITY NON REPUDIATION SECURITY

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CONT..

AUTHENTICATION The process of proving ones identity.

PRIVACY/CONFIDENTIALITY Ensuring that no one can read the

message except intended receiver.

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CONT

INTEGRITY

Assuring the receiver that receivedmessage has not altered anyway from

the original. NON REPUDIATION

A mechanism to prove that sender really

send the received message. 12

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APPLICATIONS

Authentication Application

Electronic Mail Security

IP Security Web Security

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THANK YOU

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ANY QUARIES

?