9618 - data security, privacy, and integrity
helloooooo
back to computer science we go! today we’ll be talking about the entire chapter of data security, privacy, and integrity! but first off we need to determine these terms – which honestly is the hard part. they all sound very similar with each other and can often overlap in meaning, but cambridge does want you to have a definite answer for each definition.
There are three main areas cambridge wants you to note:
data security: making sure that the data is not lost or corrupted
data privacy: making sure that data is not authorised by the wrong people (preventing unauthorised access of data)
data integrity: making sure that data is accurate and up to date
protecting techniques
protection techniques are ways to ensure the security of your computer system and the infroamtion alongside it, these include:
passwords
passwords are the digital key to your information
it is usually recommended to have a long, complex password that cannot be easily guessed
they help information only be accessed by authorised individuals
user accounts
user accounts make sure only the authorised people have access and permissions to certain files etc
they control access to computer systems
firewall
there are two types of firewalls
hardware firewall - protecting an entire network of devices from unprotected traffic and filtering out the spam
software firewall - protecting individual devices from an onset of traffic
firewalls essentially give a protection barrier between the network and the internet
firewall prevents unwanted traffic from coming into the network, and filters them out
biometrics
biometrics are a very secure way to authenticate that a user's real identity
this includes face scans, fingerprint scans, voice recognition, and retina (eye) scans
they are a way of digital signatures
authentication
authentication is the process of verifying/ensuring that a system is secure by making the user complete tasks to verify their identity
authentication is done because bots can spam and fill out forms autonomously
digital signatures
digital signatures are a way to authenticate that the document is signed off by a person and in its original version as how it was intended by the author
its like a digital stamp of approval – who sent the data, and showing it hasn't been modified or changed
anti virus software
anti virus software detects if a software may be malicious software (malware)
this is done through the anti virus software scanning through the documents, files, and applications on the device
anti virus software may have a database of pre-known trails of malware that they are able to detect in software, executables, files, etc that are linked to a known malware
anti virus software will always check up for software updates to keep its security measures up to date
anti spyware software
anti spyware blocks malware from tracking a users keyboard inputs, browsing/internet habits/history, and accessing private files on the user's device
they able to detect and remove spyware when detected
encryption
encryption is the process of scrambling important information into random looking scribbles or text through a key or cipher, making if that the information is intercepted it cannot be immediately understood
it protects sensitive information like passwords, bank information, credit card numbers etc, especially when data is sent over a network
there are two types of encryption
symmetric encryption is when you use the same key to encrypt and decrypt the information, but you must be careful in this case so the key is not leaked
asymmetric encryption is when you use one key (public) to encrypt the information, but use another key (private) to decrypt the information. this is a lot more secure, but takes a bit longer.
network and internet risks
usually when we talk about internet and network risks, we think of things corrupting our computers or data – which is true, but cambridge wants you to be specific about the type of risks that can occur, and how they can be counteracted, alongisde the type of damage that these risks can engage.
hackers
hackers are people that manipulate network and device security vulnerabilities to gain acesss to your private information and files
hackers can cause a lot of issues, and are considered cybercriminals if they commit actions that are against the law, harmful, or illegal
hackers are people who gain unauthorised access to a computer system
they can steal sensitive data, gain control of systems, or disrupt and destroy entire networks
how do hackers gain access?
hackers can gain access through a variety of ways
they are able to manipulate out of date anti virus software for security vulnerabilities
they can bash through weak passwords that are easily guessable
they can hack through unpatched software
how to avoid being hacked
have strong passwords
ensure that your code/software is written correctly so it doesn't have any loopholes
educate users on clicking strange links from unknown email addresses
have a firewall
two factor authentication
install ande regularly update anti malware software
effects of being hacked
data breaches: hackers can gain access to personal information and can leak them
malware installation: hackers can install malware on your device that can steal information or cause chaos
data loss: hackers can delete your sensitive and important files
identity theft: hackers can steal your identity such as your ID, and make actions about your sensitive information pretending that its you
financial loss: hackers can steal your bank account information, take your money etc
phishing & pharming
what is phising?
phising is a form of social engineering where a hacker sends legitimate looking emails to someones inbox and convinces them to click on the link that will potentially steal their sensitive information
what are the effects of phising?
stolen information, lost files or data, and unauthorised access into bank accounts etc
with the loss of your sensitive information, things such as personal data loss, unauthorised bank transactions and identity theft can occur
what are the ways to prevent phising?
have strong, non guessable passwords
educate users on identifying phisers
have anti spam functionality
filter through emails
change user profle permissions to make sure they cant open executables or batches
what is pharming?
pharming is when a hacker manipulates the DNS of a website server address so that when you click onto a website, it re-directs you to another fradulent website
this is to trick the user into typing their passwords and important information into the fake website
what are the effects of pharming?
pharming steals sensitive information from users, therefore meaning effects such as identity theft, unauthorised bank transactions, and hacking into accounts can happen
how can pharming be prevented?
ensuring that code is written properly so it doesn't have any security vulnerabilities to exploit
checking URLs regularly
make sure the padlock icon is visible whenever youre visiting a site (your web browser should show this whenever entering onto a site to show that its secure)
malware
what is malware?
malware stands for malicious software, software that is made with malicious purpose to intrude into someones computer system and cause harm and issues
examples of malware include deleting files, holding files ransom for financial payment, computer being unable to be used, and internet connectivity being weak or slow
malware can exists in many forms! the three that cambridge wants you to focus on are...
trojan/trojan horse
essentially, an innocent looking, real-looking file or executable that can be downloaded onto your computer, but inside it contains malware that was not detected when you first downloaded it
computer virus
like a real virus, a computer virus has code that is intended to replicate itself so it can spread across the computer system
computer viruses causes unexpected things to occur
they can do things such as delete important files, slow the computer system down, and have certain applications not work on your device
spyware
spyware is malware that when downloaded onto your computer is able to spy on your computer activity
this includes key strokes and inputs, meaning that spyware can save your account passwords, credit card information etc
spyware can also have access to your personal, private, and sensitive files, and may even send them to third party applications
this type of software is usually hidden in other normal looking applications/software, such as games or programs
preventative measures against malware:
educating users
installing a firewall
ensuring code is written properly
regulary updating your anti virus software
keeping data safe
keeping data safe is part of data integrity, and a lot of times this comes down to making sure the right people have the right access to data/files! this is done through access rights!
what are access rights?
access rights are essentially what a user can or can't do on a network, depending on their role in the network
this pretty much make sures that the user is not tampering with anything that's not related or useful to them to make sure there aren't any issues being created
access rights are based on users roles, responsibilites, or the position of security they are in
types of access rights:
full access
able to view, open, edit, delete, modify, move, comment on said files or documents
read-only access
user is able to read, view the file
no access
user is not able to view the file or have access to it
encryption
now you often see online talking about things such as encryption tools, decrypt a code, or information blah blah blah... but this concept is integral to security measures and purposes, as it has one main job: hiding data from the people who intercept it, and not allowing them to know what it is
what is encryption?
encryption is when data is being transmitted over a network, encrypting the data scrambles the data into weird looking mumo jumbo through a cipher or key, and then sending it over to the receiver and decrypting it with a known cipher or key
encryption is done on both wireless and wired networks – but, it is especially important on wireless networks due to the fact it is very easy to intercept radio signals transmitting the information.
there are two types of encryption
symmetric encryption
data is encrypted by a key. the same key is used to decrypt the data.
this is very fast and efficient, but not as secure
asymmetric encryption
data is encrypted by a public key. it is then decrypted by a separate, private key.
this is slower, but is a lot more secure.
how is wireless data encrypted?
remember keys? they come in ue when it comes to the encryption of data over wireless networks.
every network has a set service identifier (SSID). an SSID is basically the human-read-able name of your network, "Lando's_Sushi_Restauraunt Wifi" is an SSID!
and you know how most wifi networks will have a password? with this password and the SSID (network name), the wifi system will generate a master key to encrypt all your information with!
note: the master key is NEVER shared across the network!
when a device connects to a network, they are given a copy of the master key
and whenever the device sends a request across the network, the information is encrypted with the master key into what is called cipher text!
and when the information/request is received, then
there are dedicated, standaridsed protocols such as WPA2/3 to encrypt information and requests going across the wifi network
wired data is encrypted similarily to wireless data, but they have different protocol for each application, eg http.
ok guys! final run! now its onto data integrity, validation and verification!
pleaseeee speed i want to finish this chapter sooo bad
data validation & verification
so, remember those times when you're filling out forms, and then it doesn't let you submit it because you forgot one specific box? or, when one time, you weren't allowed to reset your password because when you typed your password in for the second time, you didn't type it in correctly? well, that my friends is validation and verification! essentially making sure all ur data and info is correct before proceeding with anything :)
validation
there are a couple types of validation:
presence check
formatting check
existence check
range check
length check
limit check
check digit
what is presence check?
presence check is when the system is checking that someone has actually entered something into the designated data box, eg someone fillling out a form and making sure they have filled out every single box
what is format check?
format check checks that the data entered by the user is in the specified format that the system/form is asking for, eg, someone asks for age, the user must input a valid integer value
what is existence check?
existence check is when the system checks that the data entered actually exists in the database itself, and isn't some weird value that was made up, eg, putting in your student ID into the school database application, and the applicaton validating that you exist (haha)
what is range check?
range check is the validation method that checks if the user has entered in a value that is within the accepted range, eg entering a percentage value between 0 to 100
what is a length check?
a length check is something that checks if what the user inputs fit within a specificed range, eg a code can only be up to 4 digits
what is a limit check?
this basically just checks that a value doesn't exeed a maximum value, eg ensuring no more than 4 things can be in a list or smth like that
what is a check digit?
a check digit is formed from a standardised algorithim used all across the world to produce an integer number that is used to validate that the data input into the system is valid. it added to the end of the value. it is used to check if there are any omissions of data or errors with it
examples of things a check digit can check for:
when a user forgets or accidentally doesn't put the correct values into the system
missing information or corrupted information
typos or sounding errors (phonetic errors)
isbn codes
isbn codes usually consist about 10 digits, with something along the lines of:
123-893-192-1
as each book has a unique ISBN number, this makes check digits are used in isbn codes to make sure that the code is actually correct
an integer number is chosen specifically for the end number (9 in the above example), and goes through an algorithim to show that the ISBN book number is actually real and valid!
barcodes
as barcades have white and black lines, when they are scanned by the laser, they reflect a pattern up into the scanner to show the information of the thing that's being scanned
barcodes also have a unique code that identifies them
the last line of the bar code is usually the check digit
verification methods
what is a check sum?
a check sum is a widely standardised method of verification that the data is very in fact real and useable through the use of mathematic algorithms
it is a way for users to check if their data has been corrupted or altered
checksums are calculated through mathematic algorithms, and added to the end of the original value
and then, it goes through another algorithm to check if it matches up with the previous one
if the checksums are not the same or in accordance with each other, then we can safely assume some part of the data is wrong.
what is double entry checking?
this is when a user enters in a data value twice
this is mainly used for things such as passwords to make sure that they are identical with each other and accurate with one another
what is visual checking?
this relies on the user's verification
when the data is entered, it is visually shown to the user through a pop-up text/box and ask if its correct before continuing
if it is not correct, then the user selects the option to re-enter their information/data in again
parity checks
when looking at numbers and values of strings of bits, sometimes there can be an error you don't even know exists. this error might've been caused due to weather issues when being transmitted wirelessly, or the file might've been corrupted in transit. a great way to detect these issues is with parity checks?
the better question is though, how do parity checks work?
when a parity check is involved, they usually have one bit that acts as the parity bit.
what the parity bit is depends on the contents of the string bit, and whether it is an odd or even parity check/setting.
an odd parity setting/check means that the amount of 1s in a binary string must be odd (including the parity bit, so questions might sometimes ask you to change the parity bit accordingly)
an even parity bit is essentially the same thing as an odd parity bit, there must be an even amount of 1s in the binary bit string, including the parity bit.
when the data is transmitted through and received on the other side, the receiver is able to check if there was an issue with the transmission or if the data is accurate by seeing if anything happened to the parity checks (to see if they're odd or even etc, depending on the setting.)
one thing to note is that parity checks are often only used to check for errors or omissions or data, and not necessarily where the data has been modified, changed, altered, corrupted, or omitted. it is only a signal to see if something has gone wrong or not.
some visual examples from save my exams:
but what if we really want to find out the one bit of data that went wrong and needs to be corrected?
then, you would use a parity table
how a parity table operates is that when you have a bunch of bit strings being received, it creates a table of bits.
usually, exam questions will tell you which parity these fall under (odd/even)
your job is to look through each individual column of bits, count them, and see which one is not following the odd/even sequence
you do it both horizontally and vertically
and from there, you've crossed a point where the wrong bit is misaligned, and needing to change it to either a 1 or 0
visual example from save my exams:
thanks for reading as always!!!! another very long post, but hope this helps out my fellow cs nerds!!! as always, correct me if im wrong and have a lovely day <3