Cryptograghy

Cryptography

Cryptography is a method of protecting information and communications through the use of codes, so that only those for whom the information is intended can read and process it.

The prefix 'crypt' means Hidden (or) Vault and the suffix 'graphy' means Writing.

Cloud E Shannan is considered by many to be the father of mathematical cryptography who worked for Bell labs in the 1940's. His work influenced further cryptography research in 1970 as cited by M.E Hellman and W Diffie who developed the public key cryptography.

In cryptography the techniques which are used to protect information are obtained from mathematical concepts and a set of rule based calculations known as algorithms to convert messages in ways that make it hard to decode it.

These algorithms are used for cryptographic key generation, digital signing, verification to protect data privacy, browsing on internet and to protect confidential transactions such as credit card and debit card transactions.

Features of Cryptography

1. Confidentiality: The information can only be accessed by the person for when it is intended and no other person except him can access it.

2. Integrity: Information cannot be modified in storage or transaction between sender and intended receiver without any addition to information being deleted.

3. Non-repudiation: The sender of information cannot deny intention to send information at later stage.

4. Authentication: The identities of sender and receiver confirmed. As well as destination of information is confirmed.

Cryptography terms

• Encryption: process of looking up information using cryptography.
• Decryption: Process of unlocking the information
• Key: A secret key like password used to encrypted and decry-pt information.

keys used in cryptography

These are 2 types

1. symmetric key cryptography (private key)

2. asymmetric key cryptography (public key)

Symmetric key: it is a type of encryption schema in which the same key is used both to encrypt and decry-pt message. Such a method of encoding information has been largely used to facilitate secret communication between government and military.

symmetric key algorithms are widely applied in various types of computers to enhance data security by using this data is converted to a form that cannot be understood by anyone who does not posses the secret key to decry-pt it. The secret key that the sender and recipient both use could be a specific code that have been generated by R N G(Random Number Generation).

There are two types of algorithms

1. Block algorithms: Set lengths of bits are encrypted in blocks of electronic data with the use of specific secret key.

2. Stream algorithms: Data is encrypted as it streams instead of being retained in the systems memory.

Asymmetrical key

It is also known as public key cryptography it is relatively new method, compared to symmetric it uses two keys to encrypt a plain-text, secret key are exchanged over the internet or a large network it ensures that malicious persons do not misuse the key.

It is important to note that, anyone with a secret key can decry-pt the message and this is why asymmetric encryption uses two related keys to boosting security. 

A public key is made freely available to anyone who might want to send you a message. The second private key is kept a secret so that you can only know.

It is mostly used in communication channels, especially over the internet.

Difference between symmetric and asymmetric cryptography(key)