CSE 565 Computer Security Solution Key for Midterm 1
Question 1: (4 + 6 + 5 points) a) A simple frequency analysis will determine the difference. If a monoalphabetic substitution is used, then the statistical properties of the ciphertext should be the sam
CSE565: Computer Security
Shambhu Upadhyaya Computer Science & Eng. University at Buffalo
UB Fall 2010
Buffalo, New York, 14260
UB Fall 2010 CSE565: S. Upadhyaya Lec 1.1
8/31/10 8/31/10
Overview Lecture 1
August 31, 2010 Introduction and Motivation (15
9/15/2009
CSE 565: Computer Security
Due: Oct. 1, 2009
Project 1 – Vulnerability Analysis
1. Background
Vulnerability is a weakness in a system that makes it possible for a threat to precipitate. A threat
is a potential occurrence that can have an undesir
11/29/2015
CSE 565: Computer Security
Project 1-B
Due: Dec. 10, 2015
In Class
This part of the project is individual work. Submit an individual report not to exceed two pages.
Shorter but a clearer report is encouraged.
This is a continuation of Project 1
9/06/2016 CSE 565: Computer Security Due: In Class, Sept. 22, 2016
Homework 1
Problem 1.
Obtain manufacturers specifications on two current cryptographic products for the same algorithm, such as AES, DES, a proprietary algorithm from the manufacturer, or
9/08/2016
CSE 565: Computer Security
Project 1
Completion Date: Dec. 3, 2016
This is a unique class project to be done individually (all remaining class projects for this course
will be group projects), where you take part in an ongoing research that is f
CSE565:
CSE565: Computer
Computer Security
Security
Lectures
Lectures 3
3&
&4
4
Block
Block Ciphers
Ciphers and
and Data
Data
Encryption
Encryption Standard
Standard
Shambhu Upadhyaya
Computer Science &
Eng.
University at Buffalo
Buffalo, New York 14260
9
Active Authentication using Behavioral Biometrics
To prevent masquerading, in the absence of authenticated users. Usage of keystroke dynamics, may be
used to uniquely identify the users. [ Soft Biometrics using ML ]. Thus, the user is continuously
authent
Lecture 6
Rijndael Encryption
Initial XOR with sub-key
4 steps per round, a total of 10 rounds.
Step I Substitution performed - ( S-box )
Step II Row Shift
Step III Mix of Columns
Step IV Adding round key ( XOR with key )
Need to generate 11 distinct sub-
DES Encryption (Contd.)
Key is always different for each round, due to a left shift by 1 or 2 positions.
Initial Permutation
There are two p-boxes, one is called IP (Initial Permutation) and IP -1 (Inverse Initial Permutation).
It re-orders the input dat
Lecture Notes
1. Playfair Cipher Columnar and Row-wise
2. Hill Cipher Linear Algebra Concepts
will not be a part of the syllabus for tests
Summary
For Stream Ciphers,
I. Low Error Propagation Error in encipherment and decipherment, only affects a single c
Diffie Helman Key Exchange
Choose a prime number q.
Find its primitive roots.
[q, primitive root] = public-key.
Let, q = 97 alpha = 5.
SENDER = A
RECIEVER = B
XA = 36 , XB = 58
PRIVATE
YA = alphaXa mod q
YB = alphaXb mod q.
K = Yb Xa mod q = Ya mod Xb = 7
Cryptography and Network
Security
Chapter 8
Fourth Edition
by William Stallings
Lecture slides by Lawrie Brown
Chapter 8 Introduction to Number
Theory
The Devil said to Daniel Webster: "Set me a task I can't carry out, and I'll give you
anything in the wo
Cryptography and Network
Security
Chapter 9
Fourth Edition
by William Stallings
Lecture slides by Lawrie Brown
Chapter 9 Public Key Cryptography
and RSA
Every Egyptian received two names, which were known
respectively as the true name and the good name, o
Cryptography and Network
Security
Chapter 1
Fourth Edition
by William Stallings
Lecture slides by Lawrie Brown
Chapter 1 Introduction
The art of war teaches us to rely not on the likelihood of the
enemy's not coming, but on our own readiness to receive
hi
Cryptography and Network
Security
Chapter 3
Fourth Edition
by William Stallings
Lecture slides by Lawrie Brown
Chapter 3 Block Ciphers and the Data
Encryption Standard
All the afternoon Mungo had been working on Stern's code,
principally with the aid of t
Cryptography and Network
Security
Chapter 5
Fourth Edition
by William Stallings
Lecture slides by Lawrie Brown
Chapter 5 Advanced Encryption
Standard
"It seems very simple."
"It is very simple. But if you don't know what the key is it's
virtually indeciph
Cryptography and Network
Security
Chapter 10
Fourth Edition
by William Stallings
Lecture slides by Lawrie Brown
Chapter 10 Key Management; Other
Public Key Cryptosystems
No Singhalese, whether man or woman, would venture out
of the house without a bunch o
Cryptography and Network
Security
Chapter 2
Fourth Edition
by William Stallings
Lecture slides by Lawrie Brown
Chapter 2 Classical Encryption
Techniques
Many savages at the present day regard their names as vital
parts of themselves, and therefore take gr
Name: _
CSE 435/535 Information Retrieval Fall 2015
Midterm (90 minutes, 100 points)
Question 1: State whether the following statements are True or False (10 points)
You do not have to give reasons.
a) If the Jaccard distance between two strings is small
CSE565:
CSE565: Computer
Computer Security
Security
Lecture
Lecture 13
13
Digital
Digital Signatures
Signatures
Shambhu Upadhyaya
Computer Science &
Eng.
University at Buffalo
Buffalo, New York 14260
10/11/16
UB Fall 2016
CSE565: S. Upadhyaya
Lec 13.1
Ack
Problem 2
Two approaches to attack a cipher are:
1. Brute Force Approach:
Brute force involves the use of all possible set of keys to decrypt a cipher.
Brute force is a time consuming as well as expensive (depends on the complexity
of the cipher).
It mo
Yash Navin Kumar Jain
50206851
CSE 565 : HOME WORK 2
Question 1 (a) :
With the given hint let us take 2 bit strings as :
A
1
0
A
0
1
B
1
0
B
0
1
Computing (A xor B)
1
0
0
1
0
1
0
1
1
0
1
0
1
0
0
1
0
1
1
0
1
0
0
1
1
0
1
0
0
1
0
1
0
0
(A B)
1
1
(A B)
Now we
CSE 565 Computer Security
Solution Key for Homework 2 (Total points you can earn is 70)
All questions carry equal points.
Question 1
a) The equality in the hint can be shown by listing all 1-bit possibilities:
A
0
0
1
1
AB
0
1
1
0
B
0
1
0
1
(A B)'
1
0
0
1
CSE 565 Computer Security Solution Key for Midterm 1
Question 1: 18 (3 + 7 + 8 points)
a) If you are an adversary (cryptanalyst), how would you determine if
a given ciphertext is encrypted using either monoalphabetic
substitution or a Vigenere cipher?
Ans
CSE 565 Computer Security
Solutions to Homework 3
(Max. is 70, optional questions will not be graded, all questions carry equal points)
Problem 1:
Yes. If a plaintext block has a common factor with n then the encrypted block will also have a common
factor
CSE 565 Computer Security
Solutions to Homework 4 Problems
sh is
ar stu
ed d
vi y re
aC s
o
ou urc
rs e
eH w
er as
o.
co
m
Question 1:
The four approaches are i) secret key distribution using symmetric encryption and a KDC, ii) secret key
distribution usi