Test 2 Review. 1. (10 points) Timestamps and nonces are both used in security protocols to prevent replay attacks.
|
|
- Josephine Underwood
- 5 years ago
- Views:
Transcription
1 Test 2 Review Name Student ID number Notation: {X} Bob Apply Bob s public key to X [Y ] Bob Apply Bob s private key to Y E(P, K) Encrypt P with symmetric key K D(C, K) Decrypt C with symmetric key K h(x) Apply the cryptographic hash function h to x Directions: Read each problem carefully and provide complete but concise answers. Note that when analyzing protocols, we assume that the cryptography is secure. 1. (10 points) Timestamps and nonces are both used in security protocols to prevent replay attacks. (a) Give one significant advantage of a timestamp over a nonce. (b) Give one significant advantage of a nonce over a timestamp. 2. (10 points) Consider passwords that are stored in a file. (a) What is a salt? (b) How and why is a salt used when hashing passwords?
2 3. (10 points) (a) Methods used to prevent covert channels are inherently weak. Is it better to use such weak methods or to do nothing at all? (b) Methods used for inference control are inherently weak. Is it better to use such weak methods or to do nothing at all? (c) Suppose that the only cryptosystem you have access to is known to be weak. Is it better to use this weak system to encrypt your data or to do nothing at all? 4. (10 points) In term of Lampson s access control matrix (a) What are capabilities (C-lists)? (b) What are access control lists (ACLs)? 5. (10 points) This problem deals with biometrics. (a) What are the most significant differences between the authentication problem and the identification problem? (b) Which is the easier problem, authentication or identification? Why?
3 6. (10 points) Suppose that passwords are stored as follows, where there are 128 possible choices for each character: If a password exceeds 16 characters, it is truncated to 16 characters. If a password is less than 16 characters, it is padded with A until it is exactly 16 characters. The resulting 16-character password is split into two parts, X 0 and X 1, where X 0 consists of the first 6 characters and X 1 consists of the last 10 characters. Then we compute and store Y 0 = h(x 0 ) and Y 1 = h(x 1 ), which are used for password verification. (a) What is the expected work for an exhaustive search to recover one specific password? (b) How would you attack a password in a way that would, in general, provide a significant shortcut as compared to an exhaustive search or a standard dictionary attack? 7. (10 points) Conceptually, at which layer of the protocol stack does each of the following types of firewalls operate? (a) Packet filter (b) Stateful packet filter (c) Application proxy
4 8. (10 points) Consider the following 2-message protocol, which is based on public key cryptography. Alice Message 1 [T + 1] Bob Bob For each part below, answer the following questions: Is the protocol practical, given that Bob is a server who must deal with many clients? Who is securely authenticated and who is not? Is the session key K secure? (a) Message 1: {[T, K] Alice } Bob (b) Message 1: { Alice, [T, K] Alice } Bob (c) Message 1: Alice, {[T, K] Alice } Bob (d) Message 1: T, Alice, {[K] Alice } Bob (e) Message 1: Alice, {[T ] Alice } Bob and let K = h(t )
5 9. (10 points) Consider the following 3-message protocol, based on the shared symmetric key K AB. Message 1 Alice Message 2 Bob R B For each part below, answer the following questions: Is the protocol practical, given that Bob is a server who must deal with many clients? Who is securely authenticated and who is not? Is the session key K secure? (a) Message 1: E( Alice, K, R A, K AB ) Message 2: R A, E(R B, K AB ) (b) Message 1: Alice, E(K, R A, K AB ) Message 2: R A, E(R B, K) (c) Message 1: Alice, E(K, R A, K AB ) Message 2: R A, E(R B, K AB ) (d) Message 1: Alice, E(K, R A, K) Message 2: R A, E(R B, K AB ) (e) Message 1: Alice, R A Message 2: E(K, R A, R B, K AB )
6 10. (10 points) The Fiat-Shamir zero knowledge protocol is illustrated below. x = r 2 mod N Alice e {0, 1} Bob y = r S e mod N Suppose that N = 55 and v = 34. (a) In the first iteration of the protocol, Alice sends x = 4 in message one, Bob sends e = 1 in message two and Alice sends y = 24 in message three. Does Bob accept this iteration of the protocol? Show your work. (b) In the second iteration of the protocol, Alice sends x = 4, Bob sends e = 0, and Alice sends y = 13. Find S. Hint: 13 1 mod 55 = 17. Extra Credit: TBD
Test 2 Review. (b) Give one significant advantage of a nonce over a timestamp.
Test 2 Review Name Student ID number Notation: {X} Bob Apply Bob s public key to X [Y ] Bob Apply Bob s private key to Y E(P, K) Encrypt P with symmetric key K D(C, K) Decrypt C with symmetric key K h(x)
More informationICT 6541 Applied Cryptography Lecture 8 Entity Authentication/Identification
ICT 6541 Applied Cryptography Lecture 8 Entity Authentication/Identification Hossen Asiful Mustafa Introduction Entity Authentication is a technique designed to let one party prove the identity of another
More informationPassword. authentication through passwords
Password authentication through passwords Human beings Short keys; possibly used to generate longer keys Dictionary attack: adversary tries more common keys (easy with a large set of users) Trojan horse
More informationComputer Security Fall 2006 Joseph/Tygar MT 2 Solutions
CS 161 Computer Security Fall 2006 Joseph/Tygar MT 2 Solutions Problem 1. [Covert Channels] (30 points) (a) (5 points) Write down the Fiat-Shamir zero-knowledge protocol (as presented in class) where Alice
More informationUNIT - IV Cryptographic Hash Function 31.1
UNIT - IV Cryptographic Hash Function 31.1 31-11 SECURITY SERVICES Network security can provide five services. Four of these services are related to the message exchanged using the network. The fifth service
More informationElements of Cryptography and Computer and Network Security Computer Science 134 (COMPSCI 134) Fall 2016 Instructor: Karim ElDefrawy
Elements of Cryptography and Computer and Network Security Computer Science 134 (COMPSCI 134) Fall 2016 Instructor: Karim ElDefrawy Homework 3 Due: Monday, 11/28/2016 at 11:55pm PT Solution: Will be posted
More informationUser Authentication. Modified By: Dr. Ramzi Saifan
User Authentication Modified By: Dr. Ramzi Saifan Authentication Verifying the identity of another entity Computer authenticating to another computer Person authenticating to a local/remote computer Important
More informationCS /29/17. Paul Krzyzanowski 1. Fall 2016: Question 2. Distributed Systems. Fall 2016: Question 2 (cont.) Fall 2016: Question 3
Fall 2016: Question 2 You have access to a file of class enrollment lists. Each line contains {course_number, student_id}. Distributed Systems 2017 Pre-exam 3 review Selected questions from past exams
More informationKey Establishment and Authentication Protocols EECE 412
Key Establishment and Authentication Protocols EECE 412 1 where we are Protection Authorization Accountability Availability Access Control Data Protection Audit Non- Repudiation Authentication Cryptography
More informationProtocols II. Computer Security Lecture 12. David Aspinall. 17th February School of Informatics University of Edinburgh
Protocols II Computer Security Lecture 12 David Aspinall School of Informatics University of Edinburgh 17th February 2011 Outline Introduction Shared-key Authentication Asymmetric authentication protocols
More informationSecurity Handshake Pitfalls
Security Handshake Pitfalls Ahmet Burak Can Hacettepe University abc@hacettepe.edu.tr 1 Cryptographic Authentication Password authentication is subject to eavesdropping Alternative: Cryptographic challenge-response
More informationWhat did we talk about last time? Public key cryptography A little number theory
Week 4 - Friday What did we talk about last time? Public key cryptography A little number theory If p is prime and a is a positive integer not divisible by p, then: a p 1 1 (mod p) Assume a is positive
More informationCIS 4360 Introduction to Computer Security Fall WITH ANSWERS in bold. First Midterm
CIS 4360 Introduction to Computer Security Fall 2010 WITH ANSWERS in bold Name:.................................... Number:............ First Midterm Instructions This is a closed-book examination. Maximum
More informationDistributed Systems. 26. Cryptographic Systems: An Introduction. Paul Krzyzanowski. Rutgers University. Fall 2015
Distributed Systems 26. Cryptographic Systems: An Introduction Paul Krzyzanowski Rutgers University Fall 2015 1 Cryptography Security Cryptography may be a component of a secure system Adding cryptography
More informationUser Authentication. Modified By: Dr. Ramzi Saifan
User Authentication Modified By: Dr. Ramzi Saifan Authentication Verifying the identity of another entity Computer authenticating to another computer Person authenticating to a local/remote computer Important
More informationSecurity Handshake Pitfalls
Cryptographic Authentication Security Handshake Pitfalls Ahmet Burak Can Hacettepe University abc@hacettepe.edu.tr Password authentication is subject to eavesdropping Alternative: Cryptographic challenge-response
More informationBCA III Network security and Cryptography Examination-2016 Model Paper 1
Time: 3hrs BCA III Network security and Cryptography Examination-2016 Model Paper 1 M.M:50 The question paper contains 40 multiple choice questions with four choices and student will have to pick the correct
More informationCS 161 Computer Security
Paxson Spring 2017 CS 161 Computer Security Discussion 6 Week of March 6, 2017 Question 1 Password Hashing (10 min) When storing a password p for user u, a website randomly generates a string s (called
More informationHOST Authentication Overview ECE 525
Authentication Overview Authentication refers to the process of verifying the identity of the communicating principals to one another Usually sub-divided into Entity authentication Authentication in real-time
More informationStudy Guide for the Final Exam
YALE UNIVERSITY DEPARTMENT OF COMPUTER SCIENCE CPSC 467b: Cryptography and Computer Security Handout #22 Professor M. J. Fischer April 30, 2005 1 Exam Coverage Study Guide for the Final Exam The final
More informationKurose & Ross, Chapters (5 th ed.)
Kurose & Ross, Chapters 8.2-8.3 (5 th ed.) Slides adapted from: J. Kurose & K. Ross \ Computer Networking: A Top Down Approach (5 th ed.) Addison-Wesley, April 2009. Copyright 1996-2010, J.F Kurose and
More informationAuthentication Part IV NOTE: Part IV includes all of Part III!
Authentication Part IV NOTE: Part IV includes all of Part III! ECE 3894 Hardware-Oriented Security and Trust Spring 2018 Assoc. Prof. Vincent John Mooney III Georgia Institute of Technology NOTE: THE FOLLOWING
More informationSecurity Handshake Pitfalls
Security Handshake Pitfalls 1 Authentication Handshakes Secure communication almost always includes an initial authentication handshake: Authenticate each other Establish sessions keys This process may
More informationPublic-key Cryptography: Theory and Practice
Public-key Cryptography Theory and Practice Department of Computer Science and Engineering Indian Institute of Technology Kharagpur Chapter 1: Overview What is Cryptography? Cryptography is the study of
More informationECEN 5022 Cryptography
Introduction University of Colorado Spring 2008 Historically, cryptography is the science and study of secret writing (Greek: kryptos = hidden, graphein = to write). Modern cryptography also includes such
More informationIdeal Security Protocol. Identify Friend or Foe (IFF) MIG in the Middle 4/2/2012
Ideal Security Protocol Satisfies security requirements Requirements must be precise Efficient Small computational requirement Small bandwidth usage, network delays Not fragile Works when attacker tries
More informationLecture 7 - Applied Cryptography
CSE497b Introduction to Computer and Network Security - Spring 2007 - Professor Jaeger Lecture 7 - Applied Cryptography CSE497b - Spring 2007 Introduction Computer and Network Security Professor Jaeger
More informationECE596C: Handout #9. Authentication Using Shared Secrets. Electrical and Computer Engineering, University of Arizona, Loukas Lazos
ECE596C: Handout #9 Authentication Using Shared Secrets Electrical and Computer Engineering, University of Arizona, Loukas Lazos Abstract. In this lecture we introduce the concept of authentication and
More informationBasic Concepts and Definitions. CSC/ECE 574 Computer and Network Security. Outline
CSC/ECE 574 Computer and Network Security Topic 2. Introduction to Cryptography 1 Outline Basic Crypto Concepts and Definitions Some Early (Breakable) Cryptosystems Key Issues 2 Basic Concepts and Definitions
More informationCS Computer Networks 1: Authentication
CS 3251- Computer Networks 1: Authentication Professor Patrick Traynor 4/14/11 Lecture 25 Announcements Homework 3 is due next class. Submit via T-Square or in person. Project 3 has been graded. Scores
More information10/1/2015. Authentication. Outline. Authentication. Authentication Mechanisms. Authentication Mechanisms. Authentication Mechanisms
Authentication IT443 Network Security Administration Instructor: Bo Sheng Authentication Mechanisms Key Distribution Center and Certificate Authorities Session Key 1 2 Authentication Authentication is
More informationLecture 1: Course Introduction
Lecture 1: Course Introduction Thomas Johansson T. Johansson (Lund University) 1 / 37 Chapter 9: Symmetric Key Distribution To understand the problems associated with managing and distributing secret keys.
More informationAuthenticating People and Machines over Insecure Networks
Authenticating People and Machines over Insecure Networks EECE 571B Computer Security Konstantin Beznosov authenticating people objective Alice The Internet Bob Password= sesame Password= sesame! authenticate
More informationElements of Cryptography and Computer and Networking Security Computer Science 134 (COMPSCI 134) Fall 2016 Instructor: Karim ElDefrawy
Elements of Cryptography and Computer and Networking Security Computer Science 134 (COMPSCI 134) Fall 2016 Instructor: Karim ElDefrawy Homework 2 Due: Friday, 10/28/2016 at 11:55pm PT Will be posted on
More informationח'/סיון/תשע "א. RSA: getting ready. Public Key Cryptography. Public key cryptography. Public key encryption algorithms
Public Key Cryptography Kurose & Ross, Chapters 8.28.3 (5 th ed.) Slides adapted from: J. Kurose & K. Ross \ Computer Networking: A Top Down Approach (5 th ed.) AddisonWesley, April 2009. Copyright 19962010,
More informationPublic-Key Cryptography. Professor Yanmin Gong Week 3: Sep. 7
Public-Key Cryptography Professor Yanmin Gong Week 3: Sep. 7 Outline Key exchange and Diffie-Hellman protocol Mathematical backgrounds for modular arithmetic RSA Digital Signatures Key management Problem:
More informationComputer Security. 08r. Pre-exam 2 Last-minute Review Cryptography. Paul Krzyzanowski. Rutgers University. Spring 2018
Computer Security 08r. Pre-exam 2 Last-minute Review Cryptography Paul Krzyzanowski Rutgers University Spring 2018 March 26, 2018 CS 419 2018 Paul Krzyzanowski 1 Cryptographic Systems March 26, 2018 CS
More informationAuthentication. Strong Password Protocol. IT352 Network Security Najwa AlGhamdi
Authentication Strong Password Protocol 1 Strong Password Protocol Scenario : Alice uses any workstation to log to the server B, using a password to authenticate her self. Various way to do that? Use Ur
More informationCS 161 Computer Security
Paxson Spring 2011 CS 161 Computer Security Discussion 9 March 30, 2011 Question 1 Another Use for Hash Functions (8 min) The traditional Unix system for password authentication works more or less like
More informationIssues. Separation of. Distributed system security. Security services. Security policies. Security mechanism
Module 9 - Security Issues Separation of Security policies Precise definition of which entities in the system can take what actions Security mechanism Means of enforcing that policy Distributed system
More informationUser Authentication Protocols
User Authentication Protocols Class 5 Stallings: Ch 15 CIS-5370: 26.September.2016 1 Announcement Homework 1 is due today by end of class CIS-5370: 26.September.2016 2 User Authentication The process of
More informationAuthentication. Overview of Authentication systems. IT352 Network Security Najwa AlGhamdi
Authentication Overview of Authentication systems 1 Approaches for Message Authentication Authentication is process of reliably verifying the identity of someone. Authentication Schemes 1. Password-based
More informationOther Topics in Cryptography. Truong Tuan Anh
Other Topics in Cryptography Truong Tuan Anh 2 Outline Public-key cryptosystem Cryptographic hash functions Signature schemes Public-Key Cryptography Truong Tuan Anh CSE-HCMUT 4 Outline Public-key cryptosystem
More informationElements of Cryptography and Computer and Network Security Computer Science 134 (COMPSCI 134) Fall 2016 Instructor: Karim ElDefrawy
Elements of Cryptography and Computer and Network Security Computer Science 134 (COMPSCI 134) Fall 2016 Instructor: Karim ElDefrawy Homework 3 Due: Monday, 11/28/2016 at 11:55pm PT Solution: Will be posted
More information9/30/2016. Cryptography Basics. Outline. Encryption/Decryption. Cryptanalysis. Caesar Cipher. Mono-Alphabetic Ciphers
Cryptography Basics IT443 Network Security Administration Slides courtesy of Bo Sheng Basic concepts in cryptography systems Secret cryptography Public cryptography 1 2 Encryption/Decryption Cryptanalysis
More informationCryptography and Network Security. Prof. D. Mukhopadhyay. Department of Computer Science and Engineering. Indian Institute of Technology, Kharagpur
Cryptography and Network Security Prof. D. Mukhopadhyay Department of Computer Science and Engineering Indian Institute of Technology, Kharagpur Module No. # 01 Lecture No. # 38 A Tutorial on Network Protocols
More informationDr. Jinyuan (Stella) Sun Dept. of Electrical Engineering and Computer Science University of Tennessee Fall 2010
CS 494/594 Computer and Network Security Dr. Jinyuan (Stella) Sun Dept. of Electrical Engineering and Computer Science University of Tennessee Fall 2010 1 Security Handshake Pitfalls Login only Mutual
More informationCryptography Basics. IT443 Network Security Administration Slides courtesy of Bo Sheng
Cryptography Basics IT443 Network Security Administration Slides courtesy of Bo Sheng 1 Outline Basic concepts in cryptography systems Secret key cryptography Public key cryptography Hash functions 2 Encryption/Decryption
More informationProceedings of the 10 th USENIX Security Symposium
USENIX Association Proceedings of the 10 th USENIX Security Symposium Washington, D.C., USA August 13 17, 2001 THE ADVANCED COMPUTING SYSTEMS ASSOCIATION 2001 by The USENIX Association All Rights Reserved
More informationCryptographic Checksums
Cryptographic Checksums Mathematical function to generate a set of k bits from a set of n bits (where k n). k is smaller then n except in unusual circumstances Example: ASCII parity bit ASCII has 7 bits;
More informationIntroduction. CSE 5351: Introduction to cryptography Reading assignment: Chapter 1 of Katz & Lindell
Introduction CSE 5351: Introduction to cryptography Reading assignment: Chapter 1 of Katz & Lindell 1 Cryptography Merriam-Webster Online Dictionary: 1. secret writing 2. the enciphering and deciphering
More informationUser Authentication Protocols Week 7
User Authentication Protocols Week 7 CEN-5079: 2.October.2017 1 Announcement Homework 1 is posted on the class webpage Due in 2 weeks 10 points (out of 100) subtracted each late day CEN-5079: 2.October.2017
More informationCSCI 454/554 Computer and Network Security. Topic 2. Introduction to Cryptography
CSCI 454/554 Computer and Network Security Topic 2. Introduction to Cryptography Outline Basic Crypto Concepts and Definitions Some Early (Breakable) Cryptosystems Key Issues 2 Basic Concepts and Definitions
More informationCSC/ECE 774 Advanced Network Security
Computer Science CSC/ECE 774 Advanced Network Security Topic 2. Network Security Primitives CSC/ECE 774 Dr. Peng Ning 1 Outline Absolute basics Encryption/Decryption; Digital signatures; D-H key exchange;
More informationSSL/TLS. How to send your credit card number securely over the internet
SSL/TLS How to send your credit card number securely over the internet The security provided by SSL SSL is implemented at level 4 The transport control layer In practice, SSL uses TCP sockets The underlying
More informationCristina Nita-Rotaru. CS355: Cryptography. Lecture 17: X509. PGP. Authentication protocols. Key establishment.
CS355: Cryptography Lecture 17: X509. PGP. Authentication protocols. Key establishment. Public Keys and Trust Public Key:P A Secret key: S A Public Key:P B Secret key: S B How are public keys stored How
More informationOutline. Cryptography. Encryption/Decryption. Basic Concepts and Definitions. Cryptography vs. Steganography. Cryptography: the art of secret writing
Outline CSCI 454/554 Computer and Network Security Basic Crypto Concepts and Definitions Some Early (Breakable) Cryptosystems Key Issues Topic 2. Introduction to Cryptography 2 Cryptography Basic Concepts
More informationNetwork Security CHAPTER 31. Solutions to Review Questions and Exercises. Review Questions
CHAPTER 3 Network Security Solutions to Review Questions and Exercises Review Questions. A nonce is a large random number that is used only once to help distinguish a fresh authentication request from
More information1 Identification protocols
ISA 562: Information Security, Theory and Practice Lecture 4 1 Identification protocols Now that we know how to authenticate messages using MACs, a natural question is, how can we use MACs to prove that
More informationMessage authentication. Why message authentication. Authentication primitives. and secure hashing. To prevent against:
Message authentication and secure hashing Why message authentication To prevent against: Masquerade/impersonation Modification of message content Modification of message sequence Acceptance of replayed/delayed
More information1.264 Lecture 27. Security protocols Symmetric cryptography. Next class: Anderson chapter 10. Exercise due after class
1.264 Lecture 27 Security protocols Symmetric cryptography Next class: Anderson chapter 10. Exercise due after class 1 Exercise: hotel keys What is the protocol? What attacks are possible? Copy Cut and
More informationCOMP 250. Lecture 27. hashing. Nov. 10, 2017
COMP 250 Lecture 27 hashing Nov. 10, 2017 1 RECALL Map keys (type K) values (type V) Each (key, value) pairs is an entry. For each key, there is at most one value. 2 RECALL Special Case keys are unique
More informationExercises with solutions, Set 3
Exercises with solutions, Set 3 EDA625 Security, 2017 Dept. of Electrical and Information Technology, Lund University, Sweden Instructions These exercises are for self-assessment so you can check your
More informationFull file at https://fratstock.eu
Solutions Manual Introduction to Computer Security Version 1.1 M. T. Goodrich and R. Tamassia December 20, 2010 1 Terms of Use This manual contains solutions for selected exercises in the book Introduction
More informationDistributed Systems Exam 3 Review. Paul Krzyzanowski. Rutgers University. Fall 2016
Distributed Systems 2015 Exam 3 Review Paul Krzyzanowski Rutgers University Fall 2016 2013-2016 Paul Krzyzanowski 1 2015 Question 1 What information does each node need to store for a three-dimensional
More informationCIS 4360 Secure Computer Systems Applied Cryptography
CIS 4360 Secure Computer Systems Applied Cryptography Professor Qiang Zeng Spring 2017 Symmetric vs. Asymmetric Cryptography Symmetric cipher is much faster With asymmetric ciphers, you can post your Public
More informationData Integrity. Modified by: Dr. Ramzi Saifan
Data Integrity Modified by: Dr. Ramzi Saifan Encryption/Decryption Provides message confidentiality. Does it provide message authentication? 2 Message Authentication Bob receives a message m from Alice,
More informationPROTECTING CONVERSATIONS
PROTECTING CONVERSATIONS Basics of Encrypted Network Communications Naïve Conversations Captured messages could be read by anyone Cannot be sure who sent the message you are reading Basic Definitions Authentication
More informationModelling and Analysing of Security Protocol: Lecture 1. Introductions to Modelling Protocols. Tom Chothia CWI
Modelling and Analysing of Security Protocol: Lecture 1 Introductions to Modelling Protocols Tom Chothia CWI This Course This course will primarily teaching you: How to design your own secure communication
More informationDigital Signatures. Luke Anderson. 7 th April University Of Sydney.
Digital Signatures Luke Anderson luke@lukeanderson.com.au 7 th April 2017 University Of Sydney Overview 1. Digital Signatures 1.1 Background 1.2 Basic Operation 1.3 Attack Models Replay Naïve RSA 2. PKCS#1
More informationVerteilte Systeme (Distributed Systems)
Verteilte Systeme (Distributed Systems) Lorenz Froihofer l.froihofer@infosys.tuwien.ac.at http://www.infosys.tuwien.ac.at/teaching/courses/ VerteilteSysteme/ Security Threats, mechanisms, design issues
More informationModule: Cryptographic Protocols. Professor Patrick McDaniel Spring CMPSC443 - Introduction to Computer and Network Security
CMPSC443 - Introduction to Computer and Network Security Module: Cryptographic Protocols Professor Patrick McDaniel Spring 2009 1 Key Distribution/Agreement Key Distribution is the process where we assign
More informationStrong Password Protocols
Strong Password Protocols Strong Password Protocols Password authentication over a network Transmit password in the clear. Open to password sniffing. Open to impersonation of server. Do Diffie-Hellman
More informationComputer Security. 10. Exam 2 Review. Paul Krzyzanowski. Rutgers University. Spring 2017
Computer Security 10. Exam 2 Review Paul Krzyzanowski Rutgers University Spring 2017 March 23, 2018 CS 419 2017 Paul Krzyzanowski 1 Question 1(a) Suppose you come across some old text in the form GEPPQ
More informationL13. Reviews. Rocky K. C. Chang, April 10, 2015
L13. Reviews Rocky K. C. Chang, April 10, 2015 1 Foci of this course Understand the 3 fundamental cryptographic functions and how they are used in network security. Understand the main elements in securing
More informationCryptography & Key Exchange Protocols. Faculty of Computer Science & Engineering HCMC University of Technology
Cryptography & Key Exchange Protocols Faculty of Computer Science & Engineering HCMC University of Technology Outline 1 Cryptography-related concepts 2 3 4 5 6 7 Key channel for symmetric cryptosystems
More informationA hash function is strongly collision-free if it is computationally infeasible to find different messages M and M such that H(M) = H(M ).
CA4005: CRYPTOGRAPHY AND SECURITY PROTOCOLS 1 5 5.1 A hash function is an efficient function mapping binary strings of arbitrary length to binary strings of fixed length (e.g. 128 bits), called the hash-value
More informationCS 470 Spring Security. Mike Lam, Professor. a.k.a. Why on earth do Alice and Bob need to talk so much?!? Content taken from the following:
50fb6be35f4c3105 9d4ed08fb86d8887 b746c452a9c9443b 15b22f450c76218e CS 470 Spring 2017 9df7031cdbff9d10 b700a92855f16328 5b757e66d2131841 62fedd7d9131e42e Mike Lam, Professor Security a.k.a. Why on earth
More informationCSC 474/574 Information Systems Security
CSC 474/574 Information Systems Security Topic 2.1 Introduction to Cryptography CSC 474/574 By Dr. Peng Ning 1 Cryptography Cryptography Original meaning: The art of secret writing Becoming a science that
More informationNetwork Security and Cryptography. December Sample Exam Marking Scheme
Network Security and Cryptography December 2015 Sample Exam Marking Scheme This marking scheme has been prepared as a guide only to markers. This is not a set of model answers, or the exclusive answers
More informationICT 6541 Applied Cryptography. Hossen Asiful Mustafa
ICT 6541 Applied Cryptography Hossen Asiful Mustafa Basic Communication Alice talking to Bob Alice Bob 2 Eavesdropping Eve listening the conversation Alice Bob 3 Secure Communication Eve listening the
More informationCS 161 Computer Security
Popa & Wagner Spring 2016 CS 161 Computer Security Midterm 2 Print your name:, (last) (first) I am aware of the Berkeley Campus Code of Student Conduct and acknowledge that academic misconduct will be
More informationThe question paper contains 40 multiple choice questions with four choices and students will have to pick the correct one (each carrying ½ marks.).
Time: 3hrs BCA III Network security and Cryptography Examination-2016 Model Paper 2 M.M:50 The question paper contains 40 multiple choice questions with four choices and students will have to pick the
More informationPublic Key Algorithms
Public Key Algorithms 1 Public Key Algorithms It is necessary to know some number theory to really understand how and why public key algorithms work Most of the public key algorithms are based on modular
More informationCS 161 Computer Security
Popa & Wagner Spring 2016 CS 161 Computer Security Discussion 5 Week of February 19, 2017 Question 1 Diffie Hellman key exchange (15 min) Recall that in a Diffie-Hellman key exchange, there are values
More informationAIT 682: Network and Systems Security
AIT 682: Network and Systems Security Final Exam Review Instructor: Dr. Kun Sun Topics covered by Final Topic before Midterm 10% Topic after Midterm 90% Date: 12/13/2017 7:30am 10:15am Place: the same
More information(a) Symmetric model (b) Cryptography (c) Cryptanalysis (d) Steganography
Code No: RR410504 Set No. 1 1. Write short notes on (a) Symmetric model (b) Cryptography (c) Cryptanalysis (d) Steganography 3. (a) Illustrate Diffie-hellman Key Exchange scheme for GF(P) [6M] (b) Consider
More informationPart VI. Public-key cryptography
Part VI Public-key cryptography Drawbacks with symmetric-key cryptography Symmetric-key cryptography: Communicating parties a priori share some secret information. Secure Channel Alice Unsecured Channel
More informationCSC 774 Network Security
CSC 774 Network Security Topic 2. Review of Cryptographic Techniques CSC 774 Dr. Peng Ning 1 Outline Encryption/Decryption Digital signatures Hash functions Pseudo random functions Key exchange/agreement/distribution
More informationEncryption Algorithms Authentication Protocols Message Integrity Protocols Key Distribution Firewalls
Security Outline Encryption Algorithms Authentication Protocols Message Integrity Protocols Key Distribution Firewalls Overview Cryptography functions Secret key (e.g., DES) Public key (e.g., RSA) Message
More informationCS3235 Seventh set of lecture slides
CS3235 Seventh set of lecture slides Hugh Anderson National University of Singapore School of Computing October, 2007 Hugh Anderson CS3235 Seventh set of lecture slides 1 Warp 9... Outline 1 Public Key
More informationSecurity and Anonymity
Security and Anonymity Distributed Systems need a network to send messages. Any message you send in a network can be looked at by any router or machine it goes through. Further if your machine is on the
More informationOverview. Terminology. Password Storage
Class: CSG254 Network Security Team: Enigma (team 2) Kevin Kingsbury Tejas Parikh Tony Ryan Shenghan Zhang Assignment: PS3 Secure IM system Overview Our system uses a server to store the passwords, and
More informationDr. Jinyuan (Stella) Sun Dept. of Electrical Engineering and Computer Science University of Tennessee Fall 2010
CS 494/594 Computer and Network Security Dr. Jinyuan (Stella) Sun Dept. of Electrical Engineering and Computer Science University of Tennessee Fall 2010 1 Public Key Cryptography Modular Arithmetic RSA
More informationInternet security and privacy
Internet security and privacy IPsec 1 Layer 3 App. TCP/UDP IP L2 L1 2 Operating system layers App. TCP/UDP IP L2 L1 User process Kernel process Interface specific Socket API Device driver 3 IPsec Create
More informationComputer Security. 08. Cryptography Part II. Paul Krzyzanowski. Rutgers University. Spring 2018
Computer Security 08. Cryptography Part II Paul Krzyzanowski Rutgers University Spring 2018 March 23, 2018 CS 419 2018 Paul Krzyzanowski 1 Block ciphers Block ciphers encrypt a block of plaintext at a
More informationIntroduction to Modern Cryptography. Benny Chor
Introduction to Modern Cryptography Benny Chor Identification (User Authentication) Fiat-Shamir Scheme Lecture 12 Tel-Aviv University 4 January 2010 Model and Major Issues Alice wishes to prove to Bob
More informationComputer Security 3/20/18
Authentication Identification: who are you? Authentication: prove it Computer Security 08. Authentication Authorization: you can do it Protocols such as Kerberos combine all three Paul Krzyzanowski Rutgers
More informationCryptography (DES+RSA) by Amit Konar Dept. of Math and CS, UMSL
Cryptography (DES+RSA) by Amit Konar Dept. of Math and CS, UMSL Transpositional Ciphers-A Review Decryption 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 Encryption 1 2 3 4 5 6 7 8 A G O O D F R I E N D I S A T R E
More informationComputer Security. 08. Authentication. Paul Krzyzanowski. Rutgers University. Spring 2018
Computer Security 08. Authentication Paul Krzyzanowski Rutgers University Spring 2018 1 Authentication Identification: who are you? Authentication: prove it Authorization: you can do it Protocols such
More information