IP Address + Protocols + Encryption 1.3

protocol

a set of rules that governs data transmission on a network for end points in a telecommunication connection

• 2 computers will agree the comms settings + size of packet to be sent/received

HTTP

hypertext transfer protocol, used to access & receive webpages in HTML files to be sent & recieved

• HTTPS= secure, encrypts the connection

• browsers requests protocol » web server sends requested web page to user’s browser

FTP

file transfer protocol, used for sending or retrieving files to/from remote server on computer

SMTP

simple mail transfer protocol, transferring email between email servers

• client email software sends, forwards and transmits emails to outgoing mail servers

POP

post office protocol, downloads entire message to local device & deletes from the mail server

IMAP

internet message access, download the message header until message is opened & leaves the message on the server

TCP/IP

Transmission Control Protocol/Internet Protocol

• breaks up messages into packets, reassemble packets on other end

• detects errors & resend lost messages

network layer

division of network functionality where jobs & processes are split up

• each layer = diff responsibility

interoperability

different vendors & systems can work /w e/o via standardized interfaces

• allowing different systems to connect and swap components seamlessly

self-contained (layers)

functionality of 1 layer can be edited without affecting functionality of other layers

TCP/IP 4 layer model

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• Application

• Transport

• Internet

• Link Layer

encryption texts (2)

plain text- original message to be encrypted

cipertext- encrypted message

encryption key

sequence of letters, #s & other characters used to en/decrypt

encryption algorithm

the formula for encryption

SSL

secure socket layer, protocol for establishing an encrypted link between a server and client

SSL process (5 marks)

1. browser connects to a website /w SSL

2. the site requested to identify itself & sends SSL cert in response

3. browser signals to webserver which sends signed acknowledgement to start encryption sesh

4. sharing encrypted data

symmetric encryption

uses a shared secret key to en/decrypt a message

• given to recipient + agreed upon before transmission

asymmetric encryption

has a private key(decode) & public key(encode)

confidentiality

wireless network issue: any info without encryption can be intercepted & confidentiality breached

IP address

unique # used to address or identify a host node which communicates over IP on the internet

• 2 versions, IPv4 and IPv6

MAC address

Media Access Control Address

• assigned to NIC during manufacturing process

• 48 bits(6 bytes) long, 6 hexadecimals

• separated by colons

IPv4

• four 8 bit #s in range of 0-255

• separated by periods

• first 3 bytes = network identifier, 4th byte = device identifier

IPv6

• 128 bits(16 bytes)

• 8 groups of 4 hexademical digits separated by colons

• can be shortened (0000 > 0 // » ::)

differences between IP/MAC

1. IP address can change, MAC is static

2. IP address = location within network, MAC = physical devices

3. MAC = 48 bits long, IPv6 = 128 bits