[SOLVED] Csci262 assignment 2  1. you have two puzzles with parameters as follows: puzzle a: one sub–puzzle. k = 5.

1. You have two puzzles with parameters as follows:
Puzzle A: One sub–puzzle. k = 5.
Puzzle B: Four sub-puzzles. k = 3.You should provide, for both cases other than part (b), the following:
(a) The distribution of the number of cases that require each number of hashes. 1 Mark
(b) Explain the method you used to obtain your distributions. Don’t go into too many details or
show working, it’s more “I wrote a C++ program to … and then using … I …”. 0.5 Mark(c) A graph of the distribution of the data above. 0.5 Mark
(d) The average number of hashes needed. 0.5 Mark
(e) The population standard deviation for the distribution of the number of hashes needed. 0.5
MarkYou should assume that if there are N possible solutions you check the Nth by hashing even if all
others have failed and there has to be a solution.2. Using a TCP SYN spoofing attack, the attacker aims to flood the table of TCP connection requests
on a system so that it is unable to respond to legitimate connection requests. Consider a server
system with a table for 512 connection requests.This system will retry sending the SYN-ACK
packet five times when it fails to receive an ACK packet in response, at 30 second intervals, before
purging the request from its table. Assume that no additional countermeasures are used against this
attack and that the attacker has filled this table with an initial flood of connection requests. At
what rate (per minute) must the attacker continue to send TCP connection requests to this system
in order to ensure that the table remains full? Assuming that the TCP SYN packet is 32 bytes in
size. How much bandwidth does the attacker consume to continue this attack? 1 Mark3. Consider that the incidence of viral attachments in email messages in 1 in 250. Your malware checker
will correctly identify a message as viral 95% of the time. Your malware checker will correctly identify
a message as non–viral 95% of the time. Your malware checker has just flagged a message as being
malware. What is the probability that the message is actually okay (no malware)? Justify your
answer using Bayes theorem. 1 Mark4. Many websites use a CAPTCHA image on their login page. A typical application of this is in an
HTML form asking for the email ID and the login password of a user. The webpage also shows some
numbers and letters, modified in a manner such that it is still easy for a human to recognize these
characters. The user is then asked to recognize these characters and is granted login access only
when they successfully enter the characters. Explain how using a CAPTCHA can help prevent email
spam. What is the main difficulty with using CAPTCHAs?. 1 Marks5. What are honeypots? How are they better at resisting spam bots than CAPTCHAs? 1 Mark
6. Briefly describe, in your own words, each of the following. Be sure to specify the domain and nature
of each.
(a) WannaCry. 0.5 Mark
(b) XML Bomb. 0.5 Mark7. Consider the database below and answer the questions based on it.
Name Gender School Position Salary
Alex Male Computing Lecturer $80,000
Bob Male Mathematics Lecturer $60,000
Carol Female Mathematics Lecturer $100,000
Diana Female Computing Lecturer $65,000
Ewen Male Physics Lecturer $72,000
Fran Female Physics Lecturer $98,000
Gary Male Computing Administrator $40,000
Humphry Male Mathematics Lecturer $72,000
Ivana Female Computing Tutor $12,000
Jeff Male Physics Administrator $80,000
Kim Female Mathematics Lecturer $100,000
Lex Male Computing Tutor $12,000
Morris Male Engineering Tutor $15,000Assume you only have a statistical interface, so only aggregate queries will be successful. You know
Fran is a female Physics Lecturer and Dania is a female Computing lecturer. The questions below
explore how we might determine her salary using inference, in the presence of various query size
restrictions.(a) Assume there is no limit on the query size. Give a sequence of two queries that will identify
the salary of Fran. 1 Mark
(b) Suppose that there is a lower and upper query size limit that satisfies
k ≤ |X(C)| ≤ N − k
with k = 2. Show a sequence of queries that could be used to determine Diana’s salary.
1 MarkNotes on submission
1. Submission is via Moodle. Your submission file should be a PDF file.
2. Late submissions will be marked with a 25% deduction for each day, including days over the weekend.3. Submissions more than three days late will not be marked, unless an extension has been granted.
4. If you need an extension apply through SOLS, if possible before the assignment deadline.
5. Plagiarism is treated seriously. Students involved will likely receive zero.