cuaderno+ITGS

=﻿Networks=

Definition: A network is the interconnection of of computers to share data. There are two types of networks: wirered and wireless. within wired networks there are three subtypes: Bus, Ring and star.On the other hand wireless networks, as their name says, do not use cables. A clear example might be the Wi-fi conection, which uses an access point and a wireless anthena.

Wifi networks: wifi networks are wireless networks. these use an access point that sends the wifi identification (ID) accross a certain perimeter. if a computer wants to connect to it, this will have to identify the ID and later send a request for access. If the computer receives a positive answer then this will be able to connect to it. It has to be said that wifi networks amy be protected and the ID is an encrypted message only deencryptable with a password. There are four types of wifi network security:
 * WEP
 * WPA
 * WPA2
 * No protection

These (below) are the different types of wired network configurations:

=**Encryption**=

Encryption is a way of encoding information in order to make it unreadable in case it is "stolen" in the network. Encryption converts the text or data into a form called ciphertext. Decryption is the process of decoding the encrypted message. In order to decode the encrypted message you need the correct decryption key.

"Encryption/decryption is especially important in wireless communications. This is because wireless circuits are easier to tap than their hard-wired counterparts. Nevertheless, encryption/decryption is a good idea when carrying out any kind of sensitive transaction, such as a credit-card purchase online, or the discussion of a company secret between different departments in the organization. The stronger the cipher -- that is, the harder it is for unauthorized people to break it -- the better, in general. However, as the strength of encryption/decryption increases, so does the cost."

An example of an encrypted message:

A video explaining the encryption method :D

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