Network Security Fundamentals Assignment

SECURITY
FUNDAMENTALS

ABSTRACT
This report will lay emphasis on five research questions such as: Importance of availability,
confidentiality and integrity requirements associated with ATM Machine. Calculation of
maximum number of PIN that can be entered to discover correct PIN. Reasons due to which
people may be reluctant for using biometrics authentication and ways to counter such
obligations. Two circumstances in which false negatives are mostly considered more serious as
compared to false positives. Steps to decipher a text.

TABLE OF CONTENTS
ABSTRACT.....................................................................................................................................2
TABLE OF CONTENTS.................................................................................................................3
Question 1........................................................................................................................................1
Importance of availability, confidentiality and integrity requirements associated with ATM
Machine........................................................................................................................................1
Question 2........................................................................................................................................1
Calculation of maximum number of PIN that can be entered to discover correct PIN...............1
Question 3........................................................................................................................................1
Reasons due to which people may be reluctant for using biometrics authentication and ways to
counter such obligations..............................................................................................................1
Question 4........................................................................................................................................2
Two circumstances in which false negatives are mostly considered more serious as compared
to false positives...........................................................................................................................2
Question 5........................................................................................................................................3
Steps to decipher a text................................................................................................................3
REFERENCES................................................................................................................................4

Question 1
Importance of availability, confidentiality and integrity requirements associated with ATM
Machine
 Confidentiality is one of the main and basic requirement of ATM machines as
confidentiality helps the users to keep their ATM's PIN confidential so that no can know
their pin and only authorised users can operate it (Meridji & et.al., 2019).
 Integrity is also important as it helps in authenticating the data and user of ATM machine.
In other words data entered by the users is authenticated and authorised by a third party
so that it can be verified that the data entered by the person is the original user of the data.
 Availability requirements are important because it helps the user to access all the
facilities of ATM machine and should not face any kind of denial. For example: if the
user wants to withdraw some cash then they can easily withdraw any amount of cash
entered by the user.
Question 2
Calculation of maximum number of PIN that can be entered to discover correct PIN
The total number of keys in ATM machine are 10(0,1,2,3,4,5,6,7,8,9). But since the thief
broke 5 keys, so only 5 keys are remaining. So here n=5. (5keys left.) and r=4 (4 digits are used
for pin) and since repetition is allowed. Applying Permutation Formula, for maximum number of
pins to be entered are 624 since 1 of the possible Permutation is the card holder pin itself.
Question 3
Reasons due to which people may be reluctant for using biometrics authentication and ways to
counter such obligations
Biometric authentication is a technologies through which identification and authorisation of
people is done based on their physical characteristics. It can be a finger print scan, retina and iris
scan, facial recognition, voice recognition or any other kind of scan (Srinivasan & Raja, 2016).
But there are few reasons due to which people feel reluctant for using biometric authentication
such as:
 First of all people feel that biometrics are not private i.e. anyone can see and observe
them as they are completely different for everyone. So because of this anyone can know
what is the password by observing the user.
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 Second is that biometrics are easily hackable i.e. if someone has a picture of user's ear,
eye or has their fingerprint then they can easily access the machine through users account
(Cook, 2019).
 Another problem is that it requires proper environment otherwise ID becomes unreliable.
For example if a person wants to access their account through facial recognition then
their face should be in proper position and should have light on their face.
These obligations can be countered through:
 There is always light available in ATM machine rooms so ID unreliable is no problem.
 Users can use the machine and go their identity will not be captured by anyone.
 No one accept the users are allowed in ATM machine room so their password can be kept
private and no one will know what is the password of their Account.
Question 4
Two circumstances in which false negatives are mostly considered more serious as compared to
false positives
There are two main circumstances through which biometrics can create a problem for the
user to access their account (Martinovic & et.al., 2017). These circumstances are: False positive
and false negative. Most of the time it is seen that false positive much more serious problem than
false negative as in false positive someone else not the user can access and unlock users account
but in false negative users biometric sample is not accepted by the machine and is declined by
the machine.
Two circumstances in which false negatives are mostly considered more serious as compared to
false positives are:
 If the machine declines the fingerprint of the user and user does not have any other
password set to access their account then it is a serious problem because they wont be
able to access their account.
 If user gets hurt and their face or finger gets damaged which is their password then again
they wont be able to access their account which is one of the main serious issue
associated with false negative.
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Question 5
Steps to decipher a text
It is easy to identify whether transposition technique has been used or not because in
transposition technique letters of plain text message are used but orders of letters is permuted. So
it becomes easy to spot transposition cipher as letter frequencies are mimic as compared to usual
frequencies of English. So, Let's assume that the cipher is transposition cipher based on the
pattern of the cipher. Then based on this try all kinds of transposition cipher with their code to
decipher. Then in order to read the cipher text simple matrix transposition cipher will be used.
Steps to decode matrix transposition cipher are (Hauer & Kondrak, 2016):
 First of all calculate number of columns that are required to be taken according to the
length of the message. It can be done by dividing the key and then rounding up.
 Then draw total number of boxes based on the above calculation where number of rows
is the key and columns have already been calculated.
 Subtract cipher text message length from total number of boxes then shade those boxes.
 Then start filling the characters with the cipher text from top to bottom and skip all
shaded boxes.
 Then get the plain text be reading columns from left to right.
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REFERENCES
Books and Journals
Cook, S. (2019). Why the biometrics industry needs anti-spoofing standards. Biometric
Technology Today. 2019(6). 9-11.
Hauer, B., & Kondrak, G. (2016). Decoding anagrammed texts written in an unknown language
and script. Transactions of the Association for Computational Linguistics. 4. 75-86.
Kumar, S. P., & Shanmugasundaram, N. (2018). Pin number theft recognition and cash
transaction using sixth sense technology in ATM/CDM. International Journal of
Engineering & Technology. 7(31). 178-180.
Martinovic, I., & et.al. (2017). Authentication using pulse-response biometrics. Communications
of the ACM. 60(2). 108-115.
Meridji, K., & et.al. (2019). System Security Requirements: A Framework for Early
Identification, Specification and Measurement of Related Software
Requirements. Computer Standards & Interfaces.
Srinivasan, S., & Raja, K. (2016). Preventing Cloud Attacks using Bio-Metric Authentication in
Cloud Computing. Indian Journal of Science and Technology. 9. 23.
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