L13. Reviews. Rocky K. C. Chang, April 10, 2015
|
|
- Brooke Ray
- 5 years ago
- Views:
Transcription
1 L13. Reviews Rocky K. C. Chang, April 10,
2 Foci of this course Understand the 3 fundamental cryptographic functions and how they are used in network security. Understand the main elements in securing today s Internet infrastructure. Exposed to some current Internet security problems. 2
3 Types of attacks Passive attacks (eavesdropping), e.g., ciphertext-only attacks (recognizable plaintext attacks) Fred has seen some ciphertext. known-plaintext attacks Fred has obtained some <plaintext, ciphertext> pairs. chosen-plaintext attacks Fred can choose any plaintext he wants. Active attacks, e.g., pretend to be someone else (impersonation) introduce new messages in the protocol delete existing messages substituting one message for another replay old messages 3
4 Three cryptographic functions Hash functions: require 0 key Secret key functions: require 1 key Public key functions: require 2 keys 4
5 5
6 Symmetric cryptography Secret key functions Stream cipher vs block cipher Symmetric cryptography based on substitution (confusion) and diffusion 64-bit DES and 128/192/256-bit AES Secrecy service Encrypting data of any size: cipher block chaining (CBC) Security problems with CBC, e.g., identical and nonidentical ciphertext blocks. 6
7 7
8 Cryptographic hash functions and MAC Hash functions 3 properties: pre-image resistance, collision resistance, and mixing transformation The birthday problem and attack k 1.774q, where q is the number of distinct hash outputs The length of a secure hash output 256 bits Hash function standards (MDx, SHA-x) 2 problems: length extension and partial message collision Message authentication codes A successful attack on MAC CBC-MAC and HMAC 8
9 9
10 The public-key cryptography Prime numbers, modulo a prime A group for the set of numbers modulo a prime p without 0 under multiplication Compute the multiplicative inverse using the extended Euclid algorithm. Generate a large prime number. The Rabin-Miller test determines whether an odd integer is prime. Each party involved in a public-key cryptographic system is one secret and one public key. 10
11 The Diffie-Hellman (DH) protocol The DH protocol uses the multiplicative group modulo p, where p is a very large prime. A generator g generates a set of numbers 1, g, g 2,, g t-1 (g t = 1 again). Subgroups (t < p-1) and group (t = p-1) The basic Diffie-Hellman (DH) protocol (g, p) and a random number in (1, 2,, p-1) The discrete logarithm problem Security problems Using a smaller subgroup ({1}, {1, p-1}) and a safe prime Squares and nonsquares Man in the middle attack 11
12 Alice Bob Check (p, q, g) Check (p, q, g) Randomly pick x from {1,, q-1} X = g x Check 1 < X < p and X q = 1 Y = g y Randomly pick y from Z * p Check 1 < Y < p and Y q = 1 k Y x mod p k X y mod p 12
13 The RSA algorithm In RSA, we perform modulo a composite number n = p q, where p and q are large primes. Use 2 different exponents e (public) and d (private), such that e d = 1 mod t, where t = lcm(p 1, q 1). To encrypt m, compute c = m e mod n; to decrypt c, compute c d mod n = m. To sign m, compute s = m 1/e mod n; to verify the signature, compute s e = m mod n. Choices of e, p, and q Pitfalls of using RSA, e.g., encrypting a small message, message signing. 13
14 14
15 Authentication Network-based, password-based Cryptographic authentication Symmetric and asymmetric Challenge and response Mutual authentication 2 x one-way authentication. Reflection attack and man in the middle attack Principles: One-way: Have the responder influence on what she encrypts or hashes. Have both parties have some influence over the quantity signed. 15
16 Authenticated key exchange Authenticated Diffie-Hellman exchange Perfect forward secrecy Allow both sides to agree on the crypto. algorithms and the DH parameters. A partial solution to denial-of service attacks using cookies It is prudent to couple the key exchange with authentication. 16
17 Alice Bob s min p size Randomly pick N a from {0,, } s, N a Choose (p, q, g) (p, q, g), X = g x, AUTH B Randomly pick x from {1,, q-1} Check (p, g, q), X, AUTH B Randomly pick y from {1,, q-1} Y = g y, AUTH A k h(x y mod p) Check Y, AUTH A k h(y x mod p) 17
18 18 Secure network protocols in practice
19 PKI Alice generates her public/private key pair. Keep the private key. Take the public key to the CA, say k The CA has to verify that Alice is who she says she is. The CA then issues a digital statement stating that k belongs to Alice. There will never be a single CA for all or most of all. There are going to be a large number of PKIs. Use different key pairs in different PKIs. Choose between a key server approach and a PKI approach. 19
20 IPSec Unicast, unidirectional security association at the IP layer Authentication Header and Encapsulation Security Payload Partial solution to the replay attack Tunnel mode and transport mode Encryption without authentication is useless. Outbound and inbound packet processing 20
21 IKEv.1 IKE phase 1 (ISAKMP association) and phase 2 The main mode consists of 3 message pairs. 1st pair: ISAKMP SA negotiation 2nd pair: a D-H exchange and an exchange of nonces 3rd pair: Peer authentication The phase 1 is protected with encryption and authentication. Establish IPSec associations and the necessary keys. A new issue here is hiding the identities of the end points 21
22 TLS 1.2 Pros and cons of providing security services at the transport layer instead of the IP layer. The TLS Handshake and Record layers. Session states and connection states The session states can be reused to establish a new connection. Server and client authentication 22
23 Network security is more than the above Wireless security: IEEE i, RFID, Bluetooth, IP telephony, etc Worms and buffer overflow attacks Denial-of-service and degradation-of-service attacks Data security Covert channel, privacy protection 23
24 Network security is more than the above Security policies Operational issues Human issues Vulnerability analysis Auditing Intrusion detection System security Program security etc 24
25 Security is a chain; it s only as secure as the weakest link. Security is not a product; it itself is a process. Bruce Schneier 25
Computer Security. 10r. Recitation assignment & concept review. Paul Krzyzanowski. Rutgers University. Spring 2018
Computer Security 10r. Recitation assignment & concept review Paul Krzyzanowski Rutgers University Spring 2018 April 3, 2018 CS 419 2018 Paul Krzyzanowski 1 1. What is a necessary condition for perfect
More informationDr. Jinyuan (Stella) Sun Dept. of Electrical Engineering and Computer Science University of Tennessee Fall 2010
Dr. Jinyuan (Stella) Sun Dept. of Electrical Engineering and Computer Science University of Tennessee Fall 2010 1 Photuris and SKIP PHASE 1 IKE PHASE 2 IKE How is SA established? How do parties negotiate
More informationDavid Wetherall, with some slides from Radia Perlman s security lectures.
David Wetherall, with some slides from Radia Perlman s security lectures. djw@cs.washington.edu Networks are shared: Want to secure communication between legitimate participants from others with (passive
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 informationReal-time protocol. Chapter 16: Real-Time Communication Security
Chapter 16: Real-Time Communication Security Mohammad Almalag Dept. of Computer Science Old Dominion University Spring 2013 1 Real-time protocol Parties negotiate interactively (Mutual) Authentication
More informationCSE 127: Computer Security Cryptography. Kirill Levchenko
CSE 127: Computer Security Cryptography Kirill Levchenko October 24, 2017 Motivation Two parties want to communicate securely Secrecy: No one else can read messages Integrity: messages cannot be modified
More informationCSCE 715: Network Systems Security
CSCE 715: Network Systems Security Chin-Tser Huang huangct@cse.sc.edu University of South Carolina Security in Network Layer Implementing security in application layer provides flexibility in security
More informationEncryption. INST 346, Section 0201 April 3, 2018
Encryption INST 346, Section 0201 April 3, 2018 Goals for Today Symmetric Key Encryption Public Key Encryption Certificate Authorities Secure Sockets Layer Simple encryption scheme substitution cipher:
More informationLecture 9a: Secure Sockets Layer (SSL) March, 2004
Internet and Intranet Protocols and Applications Lecture 9a: Secure Sockets Layer (SSL) March, 2004 Arthur Goldberg Computer Science Department New York University artg@cs.nyu.edu Security Achieved by
More informationCIS 6930/4930 Computer and Network Security. Final exam review
CIS 6930/4930 Computer and Network Security Final exam review About the Test This is an open book and open note exam. You are allowed to read your textbook and notes during the exam; You may bring your
More informationCS 494/594 Computer and Network Security
CS 494/594 Computer and Network Security Dr. Jinyuan (Stella) Sun Dept. of Electrical Engineering and Computer Science University of Tennessee Fall 2010 1 Real-Time Communication Security Network layers
More informationTable of Contents 1 IKE 1-1
Table of Contents 1 IKE 1-1 IKE Overview 1-1 Security Mechanism of IKE 1-1 Operation of IKE 1-1 Functions of IKE in IPsec 1-2 Relationship Between IKE and IPsec 1-3 Protocols 1-3 Configuring IKE 1-3 Configuration
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 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 informationCRYPTOGRAPHY AND NETWROK SECURITY-QUESTION BANK
CRYPTOGRAPHY AND NETWROK SECURITY-QUESTION BANK UNIT-1 1. Answer the following: a. What is Non-repudiation b. Distinguish between stream and block ciphers c. List out the problems of one time pad d. Define
More informationPublic Key Algorithms
CSE597B: Special Topics in Network and Systems Security Public Key Cryptography Instructor: Sencun Zhu The Pennsylvania State University Public Key Algorithms Public key algorithms RSA: encryption and
More informationCryptographic Systems
CPSC 426/526 Cryptographic Systems Ennan Zhai Computer Science Department Yale University Recall: Lec-10 In lec-10, we learned: - Consistency models - Two-phase commit - Consensus - Paxos Lecture Roadmap
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 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 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 informationKey Exchange. References: Applied Cryptography, Bruce Schneier Cryptography and Network Securiy, Willian Stallings
Key Exchange References: Applied Cryptography, Bruce Schneier Cryptography and Network Securiy, Willian Stallings Outlines Primitives Root Discrete Logarithm Diffie-Hellman ElGamal Shamir s Three Pass
More informationLecture 6 - Cryptography
Lecture 6 - Cryptography CMPSC 443 - Spring 2012 Introduction Computer and Network Security Professor Jaeger www.cse.psu.edu/~tjaeger/cse443-s12 Question Setup: Assume you and I donʼt know anything about
More informationSankalchand Patel College of Engineering, Visnagar Department of Computer Engineering & Information Technology. Question Bank
Sankalchand Patel College of Engineering, Visnagar Department of Computer Engineering & Information Technology Question Bank Subject: Information Security (160702) Class: BE Sem. VI (CE/IT) Unit-1: Conventional
More informationChapter 8. Network Security. Cryptography. Need for Security. An Introduction to Cryptography 10/7/2010
Cryptography Chapter 8 Network Security Introduction to Cryptography Substitution Ciphers Transposition Ciphers One-Time Pads Two Fundamental Cryptographic Principles Need for Security An Introduction
More informationCSE484 Final Study Guide
CSE484 Final Study Guide Winter 2013 NOTE: This study guide presents a list of ideas and topics that the TAs find useful to know, and may not represent all the topics that could appear on the final exam.
More informationNetwork Security Chapter 8
Network Security Chapter 8 Cryptography Symmetric-Key Algorithms Public-Key Algorithms Digital Signatures Management of Public Keys Communication Security Authentication Protocols Email Security Web Security
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 informationCSCI 454/554 Computer and Network Security. Topic 5.2 Public Key Cryptography
CSCI 454/554 Computer and Network Security Topic 5.2 Public Key Cryptography Outline 1. Introduction 2. RSA 3. Diffie-Hellman Key Exchange 4. Digital Signature Standard 2 Introduction Public Key Cryptography
More informationChapter 9 Public Key Cryptography. WANG YANG
Chapter 9 Public Key Cryptography WANG YANG wyang@njnet.edu.cn Content Introduction RSA Diffie-Hellman Key Exchange Introduction Public Key Cryptography plaintext encryption ciphertext decryption plaintext
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 informationOutline. CSCI 454/554 Computer and Network Security. Introduction. Topic 5.2 Public Key Cryptography. 1. Introduction 2. RSA
CSCI 454/554 Computer and Network Security Topic 5.2 Public Key Cryptography 1. Introduction 2. RSA Outline 3. Diffie-Hellman Key Exchange 4. Digital Signature Standard 2 Introduction Public Key Cryptography
More informationComputer Networks 1 (Mạng Máy Tính 1) Lectured by: Dr. Phạm Trần Vũ
Computer Networks 1 (Mạng Máy Tính 1) Lectured by: Dr. Phạm Trần Vũ Chapter 8 Network Security Computer Networking: A Top Down Approach, 5 th edition. Jim Kurose, Keith Ross Addison-Wesley, April 2009.
More informationData Security and Privacy. Topic 14: Authentication and Key Establishment
Data Security and Privacy Topic 14: Authentication and Key Establishment 1 Announcements Mid-term Exam Tuesday March 6, during class 2 Need for Key Establishment Encrypt K (M) C = Encrypt K (M) M = Decrypt
More informationOutline. Public Key Cryptography. Applications of Public Key Crypto. Applications (Cont d)
Outline AIT 682: Network and Systems Security 1. Introduction 2. RSA 3. Diffie-Hellman Key Exchange 4. Digital Signature Standard Topic 5.2 Public Key Cryptography Instructor: Dr. Kun Sun 2 Public Key
More informationIPSec Transform Set Configuration Mode Commands
IPSec Transform Set Configuration Mode Commands The IPSec Transform Set Configuration Mode is used to configure IPSec security parameters. There are two core protocols, the Authentication Header (AH) and
More informationIP Security IK2218/EP2120
IP Security IK2218/EP2120 Markus Hidell, mahidell@kth.se KTH School of ICT Based partly on material by Vitaly Shmatikov, Univ. of Texas Acknowledgements The presentation builds upon material from - Previous
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 information14. Internet Security (J. Kurose)
14. Internet Security (J. Kurose) 1 Network security Foundations: what is security? cryptography authentication message integrity key distribution and certification Security in practice: application layer:
More informationChapter 8. Network Security. Need for Security. An Introduction to Cryptography. Transposition Ciphers One-Time Pads
Cryptography p y Chapter 8 Network Security Introduction to Cryptography Substitution Ciphers Transposition Ciphers One-Time Pads Two Fundamental Cryptographic Principles Need for Security An Introduction
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 informationCryptography and Network Security
Cryptography and Network Security Spring 2012 http://users.abo.fi/ipetre/crypto/ Lecture 14: Folklore, Course summary, Exam requirements Ion Petre Department of IT, Åbo Akademi University 1 Folklore on
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 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
Raluca Popa Spring 2018 CS 161 Computer Security Homework 2 Due: Wednesday, February 14, at 11:59pm Instructions. This homework is due Wednesday, February 14, at 11:59pm. No late homeworks will be accepted.
More information(2½ hours) Total Marks: 75
(2½ hours) Total Marks: 75 N. B.: (1) All questions are compulsory. (2) Makesuitable assumptions wherever necessary and state the assumptions made. (3) Answers to the same question must be written together.
More informationVirtual Private Network
VPN and IPsec Virtual Private Network Creates a secure tunnel over a public network Client to firewall Router to router Firewall to firewall Uses the Internet as the public backbone to access a secure
More informationCryptography MIS
Cryptography MIS-5903 http://community.mis.temple.edu/mis5903sec011s17/ Cryptography History Substitution Monoalphabetic Polyalphabetic (uses multiple alphabets) uses Vigenere Table Scytale cipher (message
More informationSecurity. Communication security. System Security
Security Communication security security of data channel typical assumption: adversary has access to the physical link over which data is transmitted cryptographic separation is necessary System Security
More informationVPN Overview. VPN Types
VPN Types A virtual private network (VPN) connection establishes a secure tunnel between endpoints over a public network such as the Internet. This chapter applies to Site-to-site VPNs on Firepower Threat
More informationSession key establishment protocols
our task is to program a computer which gives answers which are subtly and maliciously wrong at the most inconvenient possible moment. -- Ross Anderson and Roger Needham, Programming Satan s computer Session
More informationIPSec Transform Set Configuration Mode Commands
IPSec Transform Set Configuration Mode Commands The IPSec Transform Set Configuration Mode is used to configure IPSec security parameters. There are two core protocols, the Authentication Header (AH) and
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 informationInformation Security CS 526
Information Security CS 526 Topic 14: Key Distribution & Agreement, Secure Communication Topic 14: Secure Communication 1 Readings for This Lecture On Wikipedia Needham-Schroeder protocol (only the symmetric
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 informationSession key establishment protocols
our task is to program a computer which gives answers which are subtly and maliciously wrong at the most inconvenient possible moment. -- Ross Anderson and Roger Needham, Programming Satan s computer Session
More informationJunos Security. Chapter 8: IPsec VPNs Juniper Networks, Inc. All rights reserved. Worldwide Education Services
Junos Security Chapter 8: IPsec VPNs 2012 Juniper Networks, Inc. All rights reserved. www.juniper.net Worldwide Education Services Chapter Objectives After successfully completing this chapter, you will
More informationChapter 9. Public Key Cryptography, RSA And Key Management
Chapter 9 Public Key Cryptography, RSA And Key Management RSA by Rivest, Shamir & Adleman of MIT in 1977 The most widely used public-key cryptosystem is RSA. The difficulty of attacking RSA is based on
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 informationVPNs and VPN Technologies
C H A P T E R 1 VPNs and VPN Technologies This chapter defines virtual private networks (VPNs) and explores fundamental Internet Protocol Security (IPSec) technologies. This chapter covers the following
More informationModern cryptography 2. CSCI 470: Web Science Keith Vertanen
Modern cryptography 2 CSCI 470: Web Science Keith Vertanen Modern cryptography Overview Asymmetric cryptography Diffie-Hellman key exchange (last time) Pubic key: RSA Pretty Good Privacy (PGP) Digital
More informationCSC 8560 Computer Networks: Network Security
CSC 8560 Computer Networks: Network Security Professor Henry Carter Fall 2017 Last Time We talked about mobility as a matter of context: How is mobility handled as you move around a room? Between rooms
More informationSolutions to exam in Cryptography December 17, 2013
CHALMERS TEKNISKA HÖGSKOLA Datavetenskap Daniel Hedin DIT250/TDA351 Solutions to exam in Cryptography December 17, 2013 Hash functions 1. A cryptographic hash function is a deterministic function that
More informationIntroduction and Overview. Why CSCI 454/554?
Introduction and Overview CSCI 454/554 Why CSCI 454/554? Get Credits and Graduate Security is important More job opportunities More research funds 1 Workload Five homework assignments Two exams (open book
More informationComputer Networking. What is network security? Chapter 7: Network security. Symmetric key cryptography. The language of cryptography
Chapter 7: Network security 15-441 Computer Networking Network Security: Cryptography, Authentication, Integrity Foundations: what is security? cryptography authentication message integrity key distribution
More informationSample excerpt. Virtual Private Networks. Contents
Contents Overview...................................................... 7-3.................................................... 7-5 Overview of...................................... 7-5 IPsec Headers...........................................
More informationCryptography and Network Security Chapter 16. Fourth Edition by William Stallings
Cryptography and Network Security Chapter 16 Fourth Edition by William Stallings Chapter 16 IP Security If a secret piece of news is divulged by a spy before the time is ripe, he must be put to death,
More information2.1 Basic Cryptography Concepts
ENEE739B Fall 2005 Part 2 Secure Media Communications 2.1 Basic Cryptography Concepts Min Wu Electrical and Computer Engineering University of Maryland, College Park Outline: Basic Security/Crypto Concepts
More informationSpring 2010: CS419 Computer Security
Spring 2010: CS419 Computer Security Vinod Ganapathy Lecture 7 Topic: Key exchange protocols Material: Class handout (lecture7_handout.pdf) Chapter 2 in Anderson's book. Today s agenda Key exchange basics
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 informationCisco Live /11/2016
1 Cisco Live 2016 2 3 4 Connection Hijacking - prevents the authentication happening and then an attacker jumping in during the keyexchange messaging 5 6 7 8 9 Main Mode - (spoofing attack) DH performed
More informationCS 6324: Information Security More Info on Key Establishment: RSA, DH & QKD
ERIK JONSSON SCHOOL OF ENGINEERING & COMPUTER SCIENCE Cyber Security Research and Education Institute CS 6324: Information Security Dr. Junia Valente Department of Computer Science The University of Texas
More informationVirtual Private Networks
EN-2000 Reference Manual Document 8 Virtual Private Networks O ne of the principal features of routers is their support of virtual private networks (VPNs). This document discusses transmission security,
More informationNetwork Security - ISA 656 IPsec IPsec Key Management (IKE)
Network Security - ISA 656 IPsec IPsec (IKE) Angelos Stavrou September 28, 2008 What is IPsec, and Why? What is IPsec, and Why? History IPsec Structure Packet Layout Header (AH) AH Layout Encapsulating
More informationIPSec. Slides by Vitaly Shmatikov UT Austin. slide 1
IPSec Slides by Vitaly Shmatikov UT Austin slide 1 TCP/IP Example slide 2 IP Security Issues Eavesdropping Modification of packets in transit Identity spoofing (forged source IP addresses) Denial of service
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 informationCSE 3461/5461: Introduction to Computer Networking and Internet Technologies. Network Security. Presentation L
CS 3461/5461: Introduction to Computer Networking and Internet Technologies Network Security Study: 21.1 21.5 Kannan Srinivasan 11-27-2012 Security Attacks, Services and Mechanisms Security Attack: Any
More informationLecture 2 Applied Cryptography (Part 2)
Lecture 2 Applied Cryptography (Part 2) Patrick P. C. Lee Tsinghua Summer Course 2010 2-1 Roadmap Number theory Public key cryptography RSA Diffie-Hellman DSA Certificates Tsinghua Summer Course 2010 2-2
More informationLecture 33. Firewalls. Firewall Locations in the Network. Castle and Moat Analogy. Firewall Types. Firewall: Illustration. Security April 15, 2005
Firewalls Lecture 33 Security April 15, 2005 Idea: separate local network from the Internet Trusted hosts and networks Intranet Firewall DMZ Router Demilitarized Zone: publicly accessible servers and networks
More informationNetwork Encryption 3 4/20/17
The Network Layer Network Encryption 3 CSC362, Information Security most of the security mechanisms we have surveyed were developed for application- specific needs electronic mail: PGP, S/MIME client/server
More informationConfiguring Security for VPNs with IPsec
This module describes how to configure basic IPsec VPNs. IPsec is a framework of open standards developed by the IETF. It provides security for the transmission of sensitive information over unprotected
More informationComputer Networks. Wenzhong Li. Nanjing University
Computer Networks Wenzhong Li Nanjing University 1 Chapter 7. Network Security Network Attacks Cryptographic Technologies Message Integrity and Authentication Key Distribution Firewalls Transport Layer
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 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 informationCryptography CS 555. Topic 16: Key Management and The Need for Public Key Cryptography. CS555 Spring 2012/Topic 16 1
Cryptography CS 555 Topic 16: Key Management and The Need for Public Key Cryptography CS555 Spring 2012/Topic 16 1 Outline and Readings Outline Private key management between two parties Key management
More informationProtecting Information Assets - Week 11 - Cryptography, Public Key Encryption and Digital Signatures. MIS 5206 Protecting Information Assets
Protecting Information Assets - Week 11 - Cryptography, Public Key Encryption and Digital Signatures MIS5206 Week 11 Identity and Access Control Week 10 continued Cryptography, Public Key Encryption and
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 information1.264 Lecture 28. Cryptography: Asymmetric keys
1.264 Lecture 28 Cryptography: Asymmetric keys Next class: Anderson chapters 20. Exercise due before class (Reading doesn t cover same topics as lecture) 1 Asymmetric or public key encryption Receiver
More informationLecture Nov. 21 st 2006 Dan Wendlandt ISP D ISP B ISP C ISP A. Bob. Alice. Denial-of-Service. Password Cracking. Traffic.
15-441 Lecture Nov. 21 st 2006 Dan Wendlandt Worms & Viruses Phishing End-host impersonation Denial-of-Service Route Hijacks Traffic modification Spyware Trojan Horse Password Cracking IP Spoofing DNS
More informationCS 161 Computer Security
Popa & Wagner Spring 2016 CS 161 Computer Security Midterm 2 Problem 1 True or False (10 points) Circle True or False. Do not justify your answer. (a) True or False : It is safe (IND-CPA-secure) to encrypt
More informationDiffie-Hellman. Part 1 Cryptography 136
Diffie-Hellman Part 1 Cryptography 136 Diffie-Hellman Invented by Williamson (GCHQ) and, independently, by D and H (Stanford) A key exchange algorithm o Used to establish a shared symmetric key Not for
More informationDigital Signatures. Public-Key Signatures. Arbitrated Signatures. Digital Signatures With Encryption. Terminology. Message Authentication Code (MAC)
Message Authentication Code (MAC) Key-dependent one-way hash function Only someone with a correct key can verify the hash value Easy way to turn one-way hash function into MAC is to encrypt hash value
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 informationCryptography and secure channel. May 17, Networks and Security. Thibault Debatty. Outline. Cryptography. Public-key encryption
and secure channel May 17, 2018 1 / 45 1 2 3 4 5 2 / 45 Introduction Simplified model for and decryption key decryption key plain text X KE algorithm KD Y = E(KE, X ) decryption ciphertext algorithm X
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 informationNetwork Security. Chapter 8. MYcsvtu Notes.
Network Security Chapter 8 Network Security Some people who cause security problems and why. Cryptography Introduction Substitution ciphers Transposition ciphers One-time pads Fundamental cryptographic
More informationProtocols, Technologies and Standards Secure network protocols for the OSI stack P2.1 WLAN Security WPA, WPA2, IEEE i, IEEE 802.1X P2.
P2 Protocols, Technologies and Standards Secure network protocols for the OSI stack P2.1 WLAN Security WPA, WPA2, IEEE 802.11i, IEEE 802.1X P2.2 IP Security IPsec transport mode (host-to-host), ESP and
More informationComputer Security 3/23/18
s s encrypt a block of plaintext at a time and produce ciphertext Computer Security 08. Cryptography Part II Paul Krzyzanowski DES & AES are two popular block ciphers DES: 64 bit blocks AES: 128 bit blocks
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 informationCPSC 467: Cryptography and Computer Security
CPSC 467: Cryptography and Computer Security Michael J. Fischer Lecture 11 October 4, 2017 CPSC 467, Lecture 11 1/39 ElGamal Cryptosystem Message Integrity and Authenticity Message authentication codes
More informationEEC-682/782 Computer Networks I
EEC-682/782 Computer Networks I Lecture 24 Wenbing Zhao wenbingz@gmail.com http://academic.csuohio.edu/zhao_w/teaching/eec682.htm (Lecture nodes are based on materials supplied by Dr. Louise Moser at UCSB
More information