2012-08-25T11:08:00.001-07:00

PGP

In this post I am going to discuss about cryptography. PGP stands for Pretty, Good, Privacy.

Cryptography Tool

PGP is basically an encryption tool. It is the best encryption tool and it is the easiest way to keep your information secure. It is free and also it is very efficient. It is based on a public key method. This technique is very popular in United States of America.

I want to discuss more about cryptography in this post. And for this I want to define some terms for my viewers.

Cryptography

It is a Greek word that means “secret writing”. It refers to the science and art of transforming messages to make them secure and immune to attacks.

Following components are involved in cryptography-

Sender
Plaintext
Encryption
Ciphertext
Decryption
Plain text
Receiver

Plaintext and Ciphertext

The original message before being transformed, is called plaintext. After the message is transformed, it is called ciphertext. An encryption algorithm transforms the plaintext into ciphertext and a decryption algorithm transforms the ciphertext into plaintext. The sender uses an encryption algorithm and the receiver uses a decryption algorithm.

Cipher

Encryption and decryption algorithm are known as cipher. Every sender-receiver pair does not need their very own unique cipher for a secure communication, but one cipher can serve millions of communication pairs.

Key

A key is a number or a set of numbers that the cipher as an algorithm operates on. To encrypt a message, we need an encryption algorithm, an encryption key and the plaintext. These create the ciphertext. To decrypt a message, we need a decryption algorithm, a decryption key and the ciphertext. These reveal the original plaintext.

Types of keys:-

1. Secret key
2. Public key
3. Private key
Secret key-It is the shared key used in Symmetric key cryptography.

Public key and Private key-They are used in Asymmetric key cryptography.

Alice, Bob and Eve

In cryptography, it is customary to use three characters in an information exchange scenario; we use Alice, Bob and Eve. Alice is the person who needs to send secure data. Bob is the recipient of data. Eve is the person who somehow disturbs the communication between the Alice and Bob by intercepting messages to uncover the data or by sending her own disguised messages. These three names represent computers or processes that actually send or receive data, or intercept or change data.

Categories of cryptography

We have two categories of cryptography algorithms:
1. Symmetric key cryptography (secret key)
1. Asymmetric key cryptography (public key)
Comparison

In Symmetric key cryptography, the same key locks and unlocks the box. In Asymmetric key cryptography, one key locks the box but another key is needed to unlock it.

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