INTRODUCTIONOBJECTIVEAPPLICATIONSCOMPONENTSTERMINOLOGYASPECTSTYPESADVANTAGES

Cryptography is the science of information security.

Cryptography is the science of writing in secret code.

Cryptography includes techniques such as microdots, merging words with images, and other ways to hide information in storage.

Confidentiality:-The information cannot be understood by anyone for whom it was useless.

Integrity:-The information cannot be altered in storage between sender and receiver without the alteration being detected.

Authentication:-The sender and receiver can confirm each others identity and the origin/destination of the information.

People wants and needs privacy and security while communicating.

In the past, cryptography is heavily used for militaryapplications to keep sensitive information secret from enemies.

Now a days, with the technologic progress as our dependency on electronic systems has increased we need more refined techniques.

Cryptography provides most of the methods and techniques for secure communication.

Encryption – It is a process of changing or converting normal text information into gibberish text.

Decryption – It is a process of changing or converting gibberish text back to correct message.

Cryptology : All term used for the study of secure communication over non-secure channels.

Cryptography : The process of designing systems to realize secure communications over non-secure channels.

Crypto analysis : The discipline of breaking the cryptographic systems.

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.Key management is impractical with large

number of senders and receivers.

Symmetric Cryptography:- In this type both the sender and the receiver know the same secret code, called the key. Messages are encrypted by the sender using the key and decrypted by the receiver using the same key.

Asymmetric Cryptography:- In this type pair of keys is used for encryption and decryption. These are public and private keys used for encryption and decryption.

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.

QUESTIONS