This document provides information about cryptography and encryption techniques. It discusses that cryptography is the science of information security and includes techniques to hide information. It then describes three main goals of cryptography: confidentiality, integrity, and authentication. It proceeds to define encryption as converting a message into cipher text and decryption as converting cipher text back to the original message. Finally, it explains the differences between symmetric and asymmetric encryption methods.

1. Done By:
SUBESH KUMAR YADAV
3rd Year CSE
Reg. No-1031040097

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•Cryptography is the science of information security.
•The word is derived from the
Greek kryptos, meaning hidden.
•Cryptography includes techniques such as
microdots, merging words with images, and other
ways to hide information in storage or transit.

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•Confidentiality:- The information cannot be
understood by anyone for whom it was unintended.
•Integrity :-The information cannot be altered in
storage or transit between sender and intended
receiver without the alteration being detected.
•Authentication :-The sender and receiver can
confirm each others identity and the
origin/destination of the information.

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•Encryption – It is a process of changing or
converting normal text or data information
into Cipher text.
•Decryption – It is a process of changing or
converting Cipher text back to correct
message or data by using encryption method.

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•A single common encryption key is used to
encode and decode messages.
• Both sender and receiver must know the
common key.
• The common key need to be exchanged
before hand by some other secure method.
• Symmetric encryption is simple and fast.
• But - key management is impractical with
large number of senders and receivers.
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•Asymmetric system under, which two
different keys are used to encrypt and decrypt
the message or received data packet.
• On public key is used to encrypt the data or
message and the private key on receiving
end is used to decrypt the message or data
packet.
• Each user has a Public key and a
corresponding Private (secret) key
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•Public-key cryptography Increased security
and convenience.
•Public-key cryptography is best suited for an
open multi-user environment.
•Symmetric encryption is simple and fast.

14. !Thank You!