more chp 5 Flashcards
(39 cards)
HTTP or HTTPS
a set of rules that must be obeyed while transferring anything over the internet. The S stands for secure (using TLS or SSL eg)
web browsers
software that let people access and display web pages on their device screens. Translate the HTML and show the result
what features do web browsers have
1) home page
2) bookmarks (store fav websites)
3) user history
4) user can navigate forwards and backward
5) many pages can be opened at the same time
6) make use of cookies
7) hyperlinks - points to another location
8) data is stored as a cache (temporary store)
9) Javascript
10) address bar
retrieval and location of web pages
1) to retrieve pages from a website –> you need IP address
2) DNS (domain name server, actually more than one server) is a system for finding IP addresses from a domain name in a URL (user doesn’t need to memorise)
3) converts domain name into IP address so comp can understand (202380 20384 blah blah blah)
cookies basic
small files or code stored on a users computer, sent by a web server to a browser. Small look-up table containing (key, data) pairs. Every time a user visits a website, checks if it already has cookies. Allow user tracking and maintain user preferences
Session cookies
no expiry date, stored on the computer’s temporary memory. It doesn’t collect personal data, so they cease to exist once the browser is closed or the website session is terminated. (eg virtual shopping basket)
Persistent cookies
They remember a user’s personal data, stored on the hard drive until it expires or is deleted. user has to agree to terms - removes the need to log in every time. some countries have laws to deactivate after 6 months. very efficient, don’t need to store a lot of data on the web browser. (targets users specific preferences)
what is digital currency?
purely digital, it has no physical form. it can be transferred between accounts. Eg paypal or apple pay, exists digitally but can be made into a physical format when needed.
central banking system
digital currency relies on a central banking system
eg nick –> bank x –> central bank –> bank y –> alex
problem with centralisation
confidentiality and security
cryptocurrency
uses cryptography to track transactions (decentralization)
most digital currencies are regulated by central banks and governments, but crypto has no state control, and all the rules are set by the community itself)
everything is publicly available, so all transactions can be tracked and the amount of money in the system is monitored
within a blockchain network
explain blockchaining to me love
decentralised database –> interconnected network of computers, but they arent all connected to a central server. All the transaction data is stored on ALL the computers. whenever a new transaction takes place, a copy is sent to all computers, so a change can’t be made without EVERYOEN saying yes maam
where is blockchain used? name 5
crypto, smart contracts, research, politics, education
how does it work babe?
whenever a new transaction takes place, a new block and a new hash value is created. the hash value is unique and contains a timestamp. genesis block = (block 1).
Now, all the blocks are connected as they store their hash, and the hash of the next block. This way, if they change their hash, the next block will become invalid.
why is this whole block chaining thing good
it prevents tampering, also uses proof-of work
whats proof of work
takes 10 min to determine necessary proof before adding a new block
miners
special network users who get a commission for every block created
8 cyber security threats
pharming, phishing, brute force, data interception, ddos, hacking, malware, social engineering
brute force attacks
if a hacker wants to crack ur password, they can try every possible combination. one way to reduce steps –> go through it logically. most common first, then use a word list
data interception
stealing data by ‘tapping’ into a communication link
packet sniffer –> examines data being sent over a network.
wireless - access point mapping or wardriving, data is intercepted using a laptop/smartphone, antenna and GPS device, outside somones home
wired equivalency privacy WEP encryption with a firewall
DDoS
disributed denial of service - prevent users from accessing a part of a network.
usually temporary but can be a very big breach of security
one method is flooding with spam emails etc, cant properly service a legitimate request.
hacking
gaining illegal access to a computer system, identity theft, gain of personal information
data can be deleted, corrupted, passed on
can be controlled by firewalls, usernames, strong passwords that are often changed
ethical hacking –> companies pay hackers to check hwo strong their security is
phishing
criminal sends out legitimate-looking emails to users, can bring to a different link or enter personal information.
spear fishing
targets specific individuals for financial information or industrial espionage
