**Cryptography is a strategy for securing data and interchanges using codes with the goal that solitary those for whom the data is expected can peruse and handle it.**

Cryptography is a strategy for securing data and correspondences using codes, with the goal that lone those for whom the data is planned can peruse and handle it. The prefix "sepulcher " signifies "covered up" or "vault" - and the postfix "- graphy" means "composing."

In a least difficult structure, encryption is to secret the information in some unintelligible structure so it tends to be perceived by any genuine clients.

Cryptography is the study of utilizing science to encode and unscramble information. Cryptography empowers you to store touchy data or send it across unreliable organization (like the Internet) with the goal that it can't be perused by anybody aside from the proposed beneficiary.

In software engineering, cryptogr@phy alludes to make sure about data and correspondence strategies got from numerical ideas and a bunch of rule-based figurings called calculations, to change messages in manners that are difficult to unravel. These deterministic calculations are utilized for cryptographic key age, advanced marking, check to ensure information protection, web perusing on the web, and classified correspondences, for example, Mastercard exchanges and email.

Cryptography methods

Cryptography is firmly identified with the controls of cryptology and cryptanalysis. It incorporates procedures, for example, microdots, blending words with pictures, and alternate approaches to conceal data away or travel. Notwithstanding, in the present PC driven world, cryptography is regularly connected with scrambling plaintext (normal content, in some cases alluded to as cleartext) into chipher text(a measure called encryption), at that point back once more (known as unscrambling). People who practice this field are known as cryptographers.

Current cryptography worries about the accompanying four destinations:

**Privacy: the data can't be perceived by anybody for whom it was unintended.****Respectability: the data can't be modified away or travel among sender and expected collector without the adjustment being distinguished.****Non-renouncement: the maker/sender of the data can't deny at a later stage their goals in the creation or transmission of the data.****Confirmation: the sender and collector can affirm each other's character and the inception/objective of the data.**

**Let's understand some baisc terms of a cryptography**:

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**Plain Text**:- Data that can be read and understood without any special measures is called plaintext or clear text. Orignal Message.

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**Cipher Text**:- Data thats is transformed or converted by Encryption algorithm is known as Cipher Text.

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**Encryption**:- Algorithm for transforming Plaintext to Cipher Text.

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**Decryption**:- Algorithm for transforming Cipher Text to Plaintext.

### Cryptographic algorithms

Cryptosystems utilize a bunch of methods known as cryptographic calculations, or codes, to encode and decode messages to make sure about correspondences among PC frameworks, gadgets, for example, cell phones, and applications. A code suite utilizes one calculation for encryption, another calculation for message confirmation, and another for key trade. This cycle, installed in conventions and written in programming that sudden spikes in demand for working frameworks and organized PC frameworks, includes public and private key age for information encryption/unscrambling, computerized marking and check for message verification, and key trade.

Sorts of cryptography :

1. Symmetric Key Cryptography

2. Asymmetric Key Cryptography

1. Symmetric Key Cryptography:

It utilize a solitary name key that both the sender and beneficiary have for encryption and decoding. It's a customary cryptography, likewise called mystery key or symmteric-key or private key cryptography. In this encryption framework, one key is utilized both for encryption and unscrambling. The information Encryption Standard (DES) is an illustration of a traditional cryptosystem.

Symmetric key calculation is effective; it takes less effort to scramble a message than public key calculation. Since the key is typically more modest symmetric cryptography is utilized to encode and decode long message.

2. Asysmetric Cryptography:

Its otherwise called a public key frameworks. It utilizes two keys, a public key known to everybody and a private key that lone the beneficiary of messages employments. RSA Algorithm, DSA Algorithm and Digital Signature are the case of Public-Key Systems. At the point when sender needs to send a safe message to reciever, he utilizes reciever's public key to encode the message.

Recipient at that point utilizes her Private key to unscramble it. So out in the open key cryptography pair of keys are utilized, public key for encryption and private key for unscrambling, rather than utilizing mystery key at both side like symmetric key cryptography.

# Difference Between Symmetric and Asymmetric Key Encryption:

SYMMETRIC KEY ENCRYPTION | ASYMMETRIC KEY ENCRYPTION |
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It only requires a single key for both encryption and decryption. | It requires two key one to encrypt and the other one to decrypt. |

The size of cipher text is same or smaller than the original plain text. | The size of cipher text is same or larger than the original plain text. |

The encryption process is very fast. | The encryption process is slow. |

It is used when a large amount of data is required to transfer. | It is used to transfer small amount of data. |

It only provides confidentiality. | It provides confidentiality, authenticity and non-repudiation. |

Examples: 3DES, AES, DES and RC4 | Examples: Diffie-Hellman, ECC, El Gamal, DSA and RSA |

In symmetric key encryption, resource utilization is low as compared to asymmetric key encryption. | In asymmetric key encryption, resource utilization is high. |