What is encryption?
Converting plaintext(readable data) to ciphered text (unreadable)
What is readable data
plaintext (normal text)
What is ciphered data
unreadable data
What is parity bit
A bit(0s or 1s) added to a byte to ensure total number of 1s is even for even parity check and total number of 1s is odd for odd parity check
Why is parity checking important
To ensure data was received correctly.
Define strong password policies.
Must use letters, numbers & symbols
Must be more than 10
characters
Avoid using names or simple words
Change
passwords regularly
What is biometric security
Security that uses fingerprints, facial recognition, or iris scans
Explain the purpose of 2FA
Add an extra layer of security
❓ Question:
You received the following 8-bit data packet:
CopyEdit11010111
Assume that parity is EVEN.
Yes, because we are checking for even parity and the total number of 1s is even.
❓ Question:
You received the following 8-bit data packet:
CopyEdit10110010
Assume that parity is ODD.
No, because we are checking for odd parity check but there is even total number of 1s when its supposed for the total number of 1s to be odd.
❓ Question:
You are given this 7-bit data packet:
1010110
Use even parity check
The parity bit should be 0 ( in exam you can put the parity bit in the parity bit row one!)
❓ Question:
You are given this 6-bit data packet:
110101
Use odd parity.
1,0 / 0,1 (any order is fine but the total number of ones but be odd at the 8 bit(6 bit with the extra 2 parity bit) total number of ones.)
READ THIS/ FLIP THE CARD
The exam will ask this question
Identify if data
transmission from data packet is successful by even/odd parity
This means check if the total num of ones match which parity
check you are checking.
Describe how to locate error in 2d Parity
First check each row and column and check which parity check it is
(even or odd)
If both column and row is wrong, find where a row
and column that have an issue intersect and flip that bit to fix the error.
Can parity checking fix errors?
So the data wont be sent incorrectly or
Give real world example of 2FA
(Learner's Opinion)
E.g. When you login to google by email and
password and google sends a code to the user's email to confirm and
the user must enter the code to access the account this provides two
layers of security.
Compare passwords and biometrics for security. Which is more reliable?
This question both is correct but you need a good explanation to
Passwords is more reliable rather than biometrics, because people can use a picture of your face or your fingerprint to access your account but for passwords you can put a very strong password and hackers will not be able to use brute force attacks to guess your password.
One limitation of parity checking, give one example
It can only detect odd number of errors not even number of errors, for example a data packet 11011011 has two bits changed during transmissions, 10111011, the it still has the same total number of 1s in the data packet and so the wrong data will be transmitted.