Cryptography Algorithm part II

02.15 |

The Types of Cryptography Algorithm

Cryptographic algorithm is divided into three sections based on the key he was wearing:
1. Symmetry Algorithm (using one key for encryption and decryption.
2. Asymmetry algorithm (using different keys for encryption and decryption).
3. Hash Function (one-way function).

1. Symmetry Algorithm
This algorithm is often called the classical algorithm because it uses the same key for encryption and decryption activities. This algorithm has been there since over 4000 years ago. When sending a message by using this algorithm, the recipient should be informed of the key messages from the message in order to decrypt messages sent. Security of the message that using this algorithm depends on the key. If the key is known by someone else then that person will be able to decrypt encrypted messages. The algorithm uses symmetric key among which are: - Data Encryption Standard (DES), - RC2, RC4, RC5, RC6, - International Data Encryption Algorithm (IDEA), - Advanced Encryption Standard (AES), - One Time Pad (OTP), - A5, and so forth.

2. Asymmetry Algorithm
Asymmetric algorithms are often also called public key algorithm, with the meaning of the keywords they used to do encryption and decryption are different.

In asymmetric key algorithm is divided into two parts, namely:

Public key (public key): The key may be known by everyone (unpublished).
Secret Key (private key): The key is kept secret (should only be known by one person).

The keys are related to each other. With the public key to encrypt a message but can not decrypt. Only someone who has a secret key that can decrypt the message. Algorithm asymmetry can send messages with more secure than symmetric algorithms.

Example:
Bob sends a message to Alice using asymmetric algorithms. Things to do are:
- Bob membritahukan public key to Alice
- Alice encrypts the message using Bob's public key.
- Bob decrypts the message from Alice with his secret key.
- Vice versa, if Bob wants to receive the message to Alice.

The algorithm that uses public key among which are:
- Digital Signature Algorithm (DSA),
- RSA,
- Diffie
- Hellman (DH),
- Elliptic Curve Cryptography (ECC),
- Quantum Cryptography, and other sebagainnya.

Digital Signature

3. Hash Functions
Hash function is often called one-way hash function (one-way function), message digest, fingerprint, and compression functions and message authentication code (MAC), is a mathematical function that takes variable length input and convert it into a binary sequence of length dengn fixed. Biasannya hash function is needed if you want to create a fingerprint of a message. Fingerprints on a message is a sign that the message actually originated from the person desired.

Classical and Modern Cryptography

Classical Cryptography Is an algorithm that uses one key to secure data. This technique has been used several centuries ago.

Two basic techniques commonly used in the algorithm of this type are as follows:
- Technical Substitution: Replacement of all-original text characters with other characters.
- Engineering transposition (permutation): Performed by using permutation characters.

Modern Cryptography Modern cryptography has a complexity that is very complex due to be operated using a computer.
Encoding Process How it works is very simple coding system, can dianologikan with wood, machinery, wood powder. Wood is used as a raw material for making wood dust, and to make the necessary powder machine maker.

Wood is the original text, while the engine is a cryptographic algorithm, while for the powder-making process needs action, which action is the key and sawdust is a text-code.

Stages of the process of cryptography or coding system is as follows:
- It takes algorithm, as a sequence of steps to perform encryption.
- Key, a value that is used in the algorithm so that the algorithm can work.