06/02/ Local & Metropolitan Area Networks. 0. Overview. Terminology ACOE322. Lecture 8 Network Security

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "06/02/ Local & Metropolitan Area Networks. 0. Overview. Terminology ACOE322. Lecture 8 Network Security"

Transcription

1 1 Local & Metropolitan Area Networks ACOE322 Lecture 8 Network Security Dr. L. Christofi 1 0. Overview As the knowledge of computer networking and protocols has become more widespread, so the threat of intercepting and decoding message data during its transfer across a network has increased. An intruder in a network can identify and remove the protocol control information at the head of each message, leaving the message contents. The message contents, including passwords and other sensitive information, can then be interpreted. This is know as listening or eavesdropping. In addition, an intruder can use a recorded message sequence to generate a new sequence. This is known as masquerading. Therefore, encryption should be applied to all data transfers that involve a network. In the context of the ISO reference model, the most appropriate layer to perform such operations is the presentation layer. Dr. L. Christofi 2 Terminology Data encryption involves the sending party in processing all data prior to transmission so that in case it is intercepted during transmission to be incomprehensible to the intercepting party. Data should only be interpreted (decrypted) only by the intended recipient. Most encryption methods involve the use of an encryption key, which is only known by the two correspondents. Before encryption, message data is called plaintext and after encryption, ciphertext. The aim is to chose an encryption method such as an intruder cannot decipher the recorded ciphertext in a realistic time period. Dr. L. Christofi 3 06/02/2006 1

2 2 Security Requirements Privacy (Confidentiality) Data only be accessible by authorized parties Authenticity A host or service be able to verity the identity of a user Integrity Data can be modified only by authorized parties Availability Data are available to authorized parties Non-repudiation Receiver must be able to prove that a received message came from a specific sender Dr. L. Christofi 4 Cryptography Original message Plaintext Encryption Transforms the plaintext to cipher text Decryption Transforms the ciphertext back to plain text Ciphers Different categories of algorithms in cryptography Key Number (value) that the ciphers operate on Dr. L. Christofi 5 Cryptography Components Dr. L. Christofi 6 06/02/2006 2

3 3 Encryption and Decryption In cryptography, the encryption/decryption algorithms are public; the keys are secret Two groups of algorithms Symmetric-key algorithms Public-key algorithms Dr. L. Christofi 7 Symmetric-key cryptography Same key is used by the sender (for encryption) and receiver (for decryption). The key is shared In symmetric-key cryptography, the same key is used in both directions Often used for long messages Algorithm is public, key is secret Dr. L. Christofi 8 Traditional Ciphers Substitution Ciphers Transposition Ciphers Dr. L. Christofi 9 06/02/2006 3

4 4 Substitution Ciphers One symbol is substitutes by another e.g. Caesar Cipher (a->d, b->e, c->f, z-c). Monoalphabetic substitution The relationship between a character in the plaintext to the character in the ciphertext is always one-to-one Polyalphabetic substitution The relationship between a character in the plaintext and a character in the ciphertext is one-to-many Dr. L. Christofi 10 Transposition Ciphers The characters retain their plaintext form but change their positions Text is organized into a two-dimensional table and the columns are interchanged according to a key Dr. L. Christofi 11 Block Cipher Plain text and ciphertext are block of bits Each block is a unit of encryption/decryption Dr. L. Christofi 12 06/02/2006 4

5 5 Block Cipher (Cont.) P-box S-box Product block Data Encryption Standard (DES) Triple DES Dr. L. Christofi 13 Public-key cryptography Two keys are used Private key Kept by receiver Used for decryption Public key Announced to the public Used for encryption Disadvantages Complexity of the algorithm Key is too large, calculation time is long Need to verify the association between an entity and its public key Most common algorithm RSA (Rivest, Shamir, and Adleman) More efficient for short messages Dr. L. Christofi 14 Public-key cryptography (Cont.) Dr. L. Christofi 15 06/02/2006 5

6 6 Digital signature Digital signature is used to provide Authentication Integrity Nonrepudiation Dr. L. Christofi 16 Signing the whole document The sender uses private key to encrypt (sign) the message The receiver uses the public key of the sender to decrypt the message. Note: Digital signature does not provide privacy. If there is a need for privacy, another layer of encryption/decryption must be applied. Dr. L. Christofi 17 Signing the document The sender creates a miniature version or digest of the document and signs it Using hash function is used to creates a fixed-size digest from a variable-length message Two common hash MD5: produce a 120-bit digest SHA-1: produce a 160-bit digest The receiver checks signature on miniature Dr. L. Christofi 18 06/02/2006 6

7 7 Sender and receiver site Sender Site Receiver site Dr. L. Christofi 19 User authentication Message authentication Identity of sender is verified for each single message User authentication User identity is verified once for the entire duration of system access With symmetric key With public key Sender use private key to encrypt the message Receiver uses sender s public key to decrypt the message Dr. L. Christofi 20 Using symmetric key only Simple approach Sender sends his/her identity and password in an encrypted message, using symmetric key (Kab) Can not prevent replay attack. Replay attack: malicious intruders can resend the same message Dr. L. Christofi 21 06/02/2006 7

8 8 Using symmetric key only (Cont.) Using a nonce Step 1: Sender sends his/her identity and password in an encrypted message, using symmetric key (Kab) Step 2: Receiver challenges sender by sending a nonce, which is a large random number that is used only once (one-time number), to the receiver Step 3: Receiver responds to the message by sending back the encrypted nonce using the symmetric key Advantage: can prevent replay attack Dr. L. Christofi 22 Public key authentication Sender encrypts the message with his/her private key Receiver uses sender s public key to decrypt the message and authenticate the sender Problem Cannot prevent man-in-the-middle attack Man-in-the-middle-attack: Intruder announce his/her public key to the receiver in place of a sender Dr. L. Christofi 23 Firewalls A device (usually a router or a computer) installed between the internal network of an organization and rest of the internet Help to protect an organization s computers and networks from unwanted Internet traffic Designed to keep problems in the internet from spreading to an organizations computers Classes of firewalls Packet-filter firewalls Proxy-based firewalls Dr. L. Christofi 24 06/02/2006 8

9 9 Packet-filter firewall A filter that uses a filtering table to decide which packet must be discarded (not forwarded). Filters on network layer and transport layer Block packets based on Source and destination IP addresses Source and destination ports Type of protocol (TCP or UDP) Dr. L. Christofi 25 Packet-filter firewall Dr. L. Christofi 26 Proxy firewall Focuses on application layer Filters messages based on information of the message at application layer Step 1: Runs as a proxy for destination process to receive the request Step 2: Opens the packet at the application level and finds out if the request is legitimate Step 3: If message is legitimate, act as sender process and sends the message to the real receiver. Otherwise drop the message and send an error message to the external sender Dr. L. Christofi 27 06/02/2006 9

10 10 Proxy firewall Dr. L. Christofi 28 References F. Halsall, Data Communications, Computer Networks and Open Systems, 4 th edition, Addison Wesley, 1995 W. Stallings, Data and Computer Communications, 7 th edition, Prentice Hall, 2004 Dr. L. Christofi 29 06/02/

(2½ hours) Total Marks: 75

(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 information

Ref:

Ref: Cryptography & digital signature Dec. 2013 Ref: http://cis.poly.edu/~ross/ 2 Cryptography Overview Symmetric Key Cryptography Public Key Cryptography Message integrity and digital signatures References:

More information

Cryptographic Concepts

Cryptographic Concepts Outline Identify the different types of cryptography Learn about current cryptographic methods Chapter #23: Cryptography Understand how cryptography is applied for security Given a scenario, utilize general

More information

Lecture III : Communication Security Mechanisms

Lecture III : Communication Security Mechanisms Lecture III : Communication Security Mechanisms Internet Security: Principles & Practices John K. Zao, PhD (Harvard) SMIEEE Computer Science Department, National Chiao Tung University 2 X.800 : Security

More information

BCA III Network security and Cryptography Examination-2016 Model Paper 1

BCA 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 information

Overview. SSL Cryptography Overview CHAPTER 1

Overview. SSL Cryptography Overview CHAPTER 1 CHAPTER 1 Secure Sockets Layer (SSL) is an application-level protocol that provides encryption technology for the Internet. SSL ensures the secure transmission of data between a client and a server through

More information

KALASALINGAM UNIVERSITY

KALASALINGAM UNIVERSITY KALASALINGAM UNIVERSITY (Kalasalingam Academy of Research and Education) DEPARTMENT OF COMPUTER SCIENCE AND ENGINEERING CLASS NOTES CRYPTOGRAPHY AND NETWOTK SECURITY (CSE 405) Prepared by M.RAJA AP/CSE

More information

Principles of Information Security, Fourth Edition. Chapter 8 Cryptography

Principles of Information Security, Fourth Edition. Chapter 8 Cryptography Principles of Information Security, Fourth Edition Chapter 8 Cryptography Learning Objectives Upon completion of this material, you should be able to: Chronicle the most significant events and discoveries

More information

NETWORK SECURITY & CRYPTOGRAPHY

NETWORK SECURITY & CRYPTOGRAPHY Assignment for IT Applications in Management Project On NETWORK SECURITY & CRYPTOGRAPHY Course Instructor Submitted By: Mr. ANIL KUMAR ROHIT BARVE 2013240 Section E PGDM 2013-15 Table of Contents Chapter

More information

The question paper contains 40 multiple choice questions with four choices and students will have to pick the correct one (each carrying ½ marks.).

The 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 information

Outline. Public Key Cryptography. Applications of Public Key Crypto. Applications (Cont d)

Outline. 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 information

Verteilte Systeme (Distributed Systems)

Verteilte 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 information

1.264 Lecture 28. Cryptography: Asymmetric keys

1.264 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 information

Cryptography & 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 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 information

Introduction to Cryptography. Vasil Slavov William Jewell College

Introduction to Cryptography. Vasil Slavov William Jewell College Introduction to Cryptography Vasil Slavov William Jewell College Crypto definitions Cryptography studies how to keep messages secure Cryptanalysis studies how to break ciphertext Cryptology branch of mathematics,

More information

Prof. Shervin Shirmohammadi SITE, University of Ottawa. Security Architecture. Lecture 13: Prof. Shervin Shirmohammadi CEG

Prof. Shervin Shirmohammadi SITE, University of Ottawa. Security Architecture. Lecture 13: Prof. Shervin Shirmohammadi CEG Lecture 13: Security Architecture Prof. Shervin Shirmohammadi SITE, University of Ottawa Prof. Shervin Shirmohammadi CEG 4185 13-1 Network Assets and Security Threats Assets: Hardware (PC, workstation,

More information

Security: Cryptography

Security: Cryptography Security: Cryptography Computer Science and Engineering College of Engineering The Ohio State University Lecture 38 Some High-Level Goals Confidentiality Non-authorized users have limited access Integrity

More information

FIREWALLS & NETWORK SECURITY with Intrusion Detection and VPNs, 2

FIREWALLS & NETWORK SECURITY with Intrusion Detection and VPNs, 2 FIREWALLS & NETWORK SECURITY with Intrusion Detection and VPNs, 2 nd ed. 9 Encryption and Firewalls By Whitman, Mattord & Austin 2008 Course Technology Learning Objectives Describe the role encryption

More information

Computer Security: Principles and Practice

Computer Security: Principles and Practice Computer Security: Principles and Practice Chapter 2 Cryptographic Tools First Edition by William Stallings and Lawrie Brown Lecture slides by Lawrie Brown Cryptographic Tools cryptographic algorithms

More information

Int ernet w orking. Internet Security. Literature: Forouzan: TCP/IP Protocol Suite : Ch 28

Int ernet w orking. Internet Security. Literature: Forouzan: TCP/IP Protocol Suite : Ch 28 Int ernet w orking Internet Security Literature: Forouzan: TCP/IP Protocol Suite : Ch 28 Internet Security Internet security is difficult Internet protocols were not originally designed for security The

More information

EEC-682/782 Computer Networks I

EEC-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

First Semester Examinations 2013/14 (Model Solution) INTERNET PRINCIPLES

First Semester Examinations 2013/14 (Model Solution) INTERNET PRINCIPLES PAPER CODE NO. EXAMINER : Martin Gairing COMP211 DEPARTMENT : Computer Science Tel. No. 0151 795 4264 First Semester Examinations 2013/14 (Model Solution) INTERNET PRINCIPLES TIME ALLOWED : Two Hours INSTRUCTIONS

More information

Glenda Whitbeck Global Computing Security Architect Spirit AeroSystems

Glenda Whitbeck Global Computing Security Architect Spirit AeroSystems Glenda Whitbeck Global Computing Security Architect Spirit AeroSystems History 2000 B.C. Egyptian Hieroglyphics Atbash - Hebrew Original alphabet mapped to different letter Type of Substitution Cipher

More information

Most Common Security Threats (cont.)

Most Common Security Threats (cont.) Most Common Security Threats (cont.) Denial of service (DoS) attack Distributed denial of service (DDoS) attack Insider attacks. Any examples? Poorly designed software What is a zero-day vulnerability?

More information

Cipher Suite Configuration Mode Commands

Cipher Suite Configuration Mode Commands The Cipher Suite Configuration Mode is used to configure the building blocks for SSL cipher suites, including the encryption algorithm, hash function, and key exchange. Important The commands or keywords/variables

More information

key distribution requirements for public key algorithms asymmetric (or public) key algorithms

key distribution requirements for public key algorithms asymmetric (or public) key algorithms topics: cis3.2 electronic commerce 24 april 2006 lecture # 22 internet security (part 2) finish from last time: symmetric (single key) and asymmetric (public key) methods different cryptographic systems

More information

Security: Focus of Control. Authentication

Security: Focus of Control. Authentication Security: Focus of Control Three approaches for protection against security threats a) Protection against invalid operations b) Protection against unauthorized invocations c) Protection against unauthorized

More information

ISA 662 Internet Security Protocols. Outline. Prime Numbers (I) Beauty of Mathematics. Division (II) Division (I)

ISA 662 Internet Security Protocols. Outline. Prime Numbers (I) Beauty of Mathematics. Division (II) Division (I) Outline ISA 662 Internet Security Protocols Some Math Essentials & History Asymmetric signatures and key exchange Asymmetric encryption Symmetric MACs Lecture 2 ISA 662 1 2 Beauty of Mathematics Demonstration

More information

CCNA Security 1.1 Instructional Resource

CCNA Security 1.1 Instructional Resource CCNA Security 1.1 Instructional Resource Chapter 7 Cryptographic Systems 2012 Cisco and/or its affiliates. All rights reserved. 1 Explain how cryptology consists of cryptography (encoding messages) and

More information

Public-key Cryptography: Theory and Practice

Public-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 information

Chapter 3 Traditional Symmetric-Key Ciphers 3.1

Chapter 3 Traditional Symmetric-Key Ciphers 3.1 Chapter 3 Traditional Symmetric-Key Ciphers 3.1 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 3 Objectives To define the terms and the concepts of symmetric

More information

Security: Focus of Control

Security: Focus of Control Security: Focus of Control Three approaches for protection against security threats a) Protection against invalid operations b) Protection against unauthorized invocations c) Protection against unauthorized

More information

Systems and Network Security (NETW-1002)

Systems and Network Security (NETW-1002) Systems and Network Security (NETW-1002) Dr. Mohamed Abdelwahab Saleh IET-Networks, GUC Spring 2017 Course Outline Basic concepts of security: Attacks, security properties, protection mechanisms. Basic

More information

CS 425 / ECE 428 Distributed Systems Fall 2017

CS 425 / ECE 428 Distributed Systems Fall 2017 CS 425 / ECE 428 Distributed Systems Fall 2017 Indranil Gupta (Indy) Dec 5, 2017 Lecture 27: Security All slides IG Security Threats Leakage Unauthorized access to service or data E.g., Someone knows your

More information

Other Uses of Cryptography. Cryptography Goals. Basic Problem and Terminology. Other Uses of Cryptography. What Can Go Wrong? Why Do We Need a Key?

Other Uses of Cryptography. Cryptography Goals. Basic Problem and Terminology. Other Uses of Cryptography. What Can Go Wrong? Why Do We Need a Key? ryptography Goals Protect private communication in the public world and are shouting messages over a crowded room no one can understand what they are saying 1 Other Uses of ryptography Authentication should

More information

CRYPTOGRAPHY AND NETWROK SECURITY-QUESTION BANK

CRYPTOGRAPHY 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 information

Cryptography Introduction

Cryptography Introduction Cryptography Introduction Last Updated: Aug 20, 2013 Terminology Access Control o Authentication Assurance that entities are who they claim to be o Authorization Assurance that entities have permission

More information

Distributed 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 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 information

Classical Cryptography. Thierry Sans

Classical Cryptography. Thierry Sans Classical Cryptography Thierry Sans Example and definitions of a cryptosystem Caesar Cipher - the oldest cryptosystem A shift cipher attributed to Julius Caesar (100-44 BC) MEET ME AFTER THE TOGA PARTY

More information

Internet Technology. Security

Internet Technology. Security Uni Innsbruck Informatik - 1 Internet Technology Security Michael Welzl michael.welzl@uibk.ac.at DPS NSG Team http://dps.uibk.ac.at dps.uibk.ac.at/nsg Institute of Computer Science University of Innsbruck,

More information

ISACA CISA. ISACA CISA ( Certified Information Systems Auditor ) Download Full Version :

ISACA CISA. ISACA CISA ( Certified Information Systems Auditor ) Download Full Version : ISACA CISA ISACA CISA ( Certified Information Systems Auditor ) Download Full Version : http://killexams.com/pass4sure/exam-detail/cisa QUESTION: 390 Applying a digital signature to data traveling in a

More information

Configuring Internet Key Exchange Security Protocol

Configuring Internet Key Exchange Security Protocol Configuring Internet Key Exchange Security Protocol This chapter describes how to configure the Internet Key Exchange (IKE) protocol. IKE is a key management protocol standard that is used in conjunction

More information

Chapter 6. IP Security. Dr. BHARGAVI H. GOSWAMI Department of Computer Science Christ University

Chapter 6. IP Security. Dr. BHARGAVI H. GOSWAMI Department of Computer Science Christ University Chapter 6 IP Security Dr. BHARGAVI H. GOSWAMI Department of Computer Science Christ University +91 9426669020 bhargavigoswami@gmail.com Topic List 1. IP Security Overview 2. IP Security Architecture 3.

More information

CS 332 Computer Networks Security

CS 332 Computer Networks Security CS 332 Computer Networks Security Professor Szajda Last Time We talked about mobility as a matter of context: How is mobility handled as you move around a room? Between rooms in the same building? As your

More information

Cryptography. Intercepting Information Scenario 1. Tuesday, December 9, December 9, Wireless broadcasts information using radio signals

Cryptography. Intercepting Information Scenario 1. Tuesday, December 9, December 9, Wireless broadcasts information using radio signals Cryptography December 9, 2008 1 Intercepting Information Scenario 1 Wireless broadcasts information using radio signals Any computer on a wireless network CAN listen to any network traffic http://www.geeksquad.com/

More information

3 Symmetric Key Cryptography 3.1 Block Ciphers Symmetric key strength analysis Electronic Code Book Mode (ECB) Cipher Block Chaining Mode (CBC) Some

3 Symmetric Key Cryptography 3.1 Block Ciphers Symmetric key strength analysis Electronic Code Book Mode (ECB) Cipher Block Chaining Mode (CBC) Some 3 Symmetric Key Cryptography 3.1 Block Ciphers Symmetric key strength analysis Electronic Code Book Mode (ECB) Cipher Block Chaining Mode (CBC) Some popular block ciphers Triple DES Advanced Encryption

More information

Security in ECE Systems

Security in ECE Systems Lecture 11 Information Security ECE 197SA Systems Appreciation Security in ECE Systems Information security Information can be very valuable Secure communication important to protect information Today

More information

Security Engineering. Lecture 16 Network Security Fabio Massacci (with the courtesy of W. Stallings)

Security Engineering. Lecture 16 Network Security Fabio Massacci (with the courtesy of W. Stallings) Security Lecture 16 Network Security Fabio Massacci (with the courtesy of W. Stallings) Lecture Outline Network Attacks Attive Attacks Passive Attacks TCP Attacks Contermeasures IPSec SSL/TLS Firewalls

More information

Introduction to Computer Security

Introduction to Computer Security Introduction to Computer Security Instructor: Mahadevan Gomathisankaran mgomathi@unt.edu CSCE 4550/5550, Fall 2009 Lecture 10 1 Announcements Project Group Due today Attendance Mandatory Ave. 85% ( 4 absentees

More information

Study Guide to Mideterm Exam

Study Guide to Mideterm Exam YALE UNIVERSITY DEPARTMENT OF COMPUTER SCIENCE CPSC 467b: Cryptography and Computer Security Handout #7 Professor M. J. Fischer February 20, 2012 Study Guide to Mideterm Exam For the exam, you are responsible

More information

Lecture 33. Firewalls. Firewall Locations in the Network. Castle and Moat Analogy. Firewall Types. Firewall: Illustration. Security April 15, 2005

Lecture 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 information

S. Erfani, ECE Dept., University of Windsor Network Security

S. Erfani, ECE Dept., University of Windsor Network Security 4.11 Data Integrity and Authentication It was mentioned earlier in this chapter that integrity and protection security services are needed to protect against active attacks, such as falsification of data

More information

SKP Engineering College

SKP Engineering College SKP Engineering College Tiruvannamalai 606611 A Course Material on Cryptography and Network Security By G.Rajkumar Assistant Professor Electronics and Communication Engineering Electronics and Communication

More information

Introduction to Cryptography. --- Foundations of computer security ---

Introduction to Cryptography. --- Foundations of computer security --- Introduction to Cryptography --- Foundations of computer security --- Related Chapters Cryptography CHAPTER 2, A Cryptography Primer CHAPTER 37, Data Encryption CHAPTER 39, Public Key Infrastructure CHAPTER

More information

Message authentication. Why message authentication. Authentication primitives. and secure hashing. To prevent against:

Message 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 information

COSC4377. Chapter 8 roadmap

COSC4377. Chapter 8 roadmap Lecture 28 Chapter 8 roadmap 8.1 What is network security? 8.2 Principles of cryptography 8.3 Message integrity 8.4 Securing e mail 8.5 Securing TCP connections: SSL 8.6 Network layer security: IPsec 8.7

More information

Module: Cryptographic Protocols. Professor Patrick McDaniel Spring CMPSC443 - Introduction to Computer and Network Security

Module: 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 information

Chapter 6/8. IP Security

Chapter 6/8. IP Security Chapter 6/8 IP Security Prof. Bhargavi H Goswami Department of MCA, Sunshine Group of Institutes, Rajkot, Gujarat, India. Mob: +918140099018. Email: bhargavigoswami@gmail.com Topic List 1. IP Security

More information

ICT 6541 Applied Cryptography Lecture 8 Entity Authentication/Identification

ICT 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 information

SRI VENKATESWARA COLLEGE OF ENGINEERING

SRI VENKATESWARA COLLEGE OF ENGINEERING COURSE DELIVERY PLAN - THEORY Page 1 of 6 Department of Information Technology B.E/B.Tech :IT/CS Regulation:2013 LP: CS6701 Rev. No: 01 Date: 30.06.2017 Sub. Code / Sub. Name : CS6701 CRYPTOGRAPHY & NETWORK

More information

Encryption I. An Introduction

Encryption I. An Introduction Encryption I An Introduction Reading List ADO and SQL Server Security A Simple Guide to Cryptography Protecting Private Data with the Cryptography Namespaces Using MD5 to Encrypt Passwords in a Database

More information

SMart esolutions Information Security

SMart esolutions Information Security Information Security Agenda What are SMart esolutions? What is Information Security? Definitions SMart esolutions Security Features Frequently Asked Questions 12/6/2004 2 What are SMart esolutions? SMart

More information

CSC 482/582: Computer Security. Security Protocols

CSC 482/582: Computer Security. Security Protocols Security Protocols Topics 1. Basic Concepts of Cryptography 2. Security Protocols 3. Authentication Protocols 4. Key Exchange Protocols 5. Kerberos 6. Public Key Infrastructure Encryption and Decryption

More information

Network Security Essentials

Network Security Essentials Network Security Essentials Applications and Standards Third Edition William Stallings Chapter 2 Symmetric Encryption and Message Confidentiality Dr. BHARGAVI H. GOSWAMI Department of Computer Science

More information

Cryptanalysis. Ed Crowley

Cryptanalysis. Ed Crowley Cryptanalysis Ed Crowley 1 Topics Cryptanalysis History Modern Cryptanalysis Characterization of Cryptanalysis Attacks Attack Types 2 Cryptanalysis Science of cracking ciphers and codes, decoding secrets,

More information

WAP Security. Helsinki University of Technology S Security of Communication Protocols

WAP Security. Helsinki University of Technology S Security of Communication Protocols WAP Security Helsinki University of Technology S-38.153 Security of Communication Protocols Mikko.Kerava@iki.fi 15.4.2003 Contents 1. Introduction to WAP 2. Wireless Transport Layer Security 3. Other WAP

More information

Chapter 8 Security. Computer Networking: A Top Down Approach. Andrei Gurtov. 7 th edition Jim Kurose, Keith Ross Pearson/Addison Wesley April 2016

Chapter 8 Security. Computer Networking: A Top Down Approach. Andrei Gurtov. 7 th edition Jim Kurose, Keith Ross Pearson/Addison Wesley April 2016 Chapter 8 Andrei Gurtov All material copyright 1996-2016 J.F Kurose and K.W. Ross, All Rights Reserved Computer Networking: A Top Down Approach 7 th edition Jim Kurose, Keith Ross Pearson/Addison Wesley

More information

Student ID: CS457: Computer Networking Date: 5/8/2007 Name:

Student ID: CS457: Computer Networking Date: 5/8/2007 Name: CS457: Computer Networking Date: 5/8/2007 Name: Instructions: 1. Be sure that you have 10 questions 2. Write your Student ID (email) at the top of every page 3. Be sure to complete the honor statement

More information

Firewalls, Tunnels, and Network Intrusion Detection

Firewalls, Tunnels, and Network Intrusion Detection Firewalls, Tunnels, and Network Intrusion Detection 1 Firewalls A firewall is an integrated collection of security measures designed to prevent unauthorized electronic access to a networked computer system.

More information

A Proposed Method for Cryptography using Random Key and Rotation of Text

A Proposed Method for Cryptography using Random Key and Rotation of Text Volume 6, No.2, March - April 2017 Mousumi Ghanti et al., International Journal of Advanced Trends in Computer Science and Engineering, 6(2), March - April 2017, 18-22 Available Online at http://www.warse.org/ijatcse/static/pdf/file/ijatcse03622017.pdf

More information

History Of Cryptography

History Of Cryptography 1 Cryptography History Of Cryptography Pen and Paper Cryptography 2000 B.C. 1750 AD Examples: Caesar Vigenère Mechanical cipher machines 1750-1950 Confederate Army s Cipher Disk Japanese Red and Purple

More information

E-Commerce Security Pearson Prentice Hall, Electronic Commerce 2008, Efraim Turban, et al.

E-Commerce Security Pearson Prentice Hall, Electronic Commerce 2008, Efraim Turban, et al. E-Commerce Security 2008 Pearson Prentice Hall, Electronic Commerce 2008, Efraim Turban, et al. Learning Objectives 1. Explain EC-related crimes and why they cannot be stopped. 2. Describe an EC security

More information

Elements of Security

Elements of Security Elements of Security Dr. Bill Young Department of Computer Sciences University of Texas at Austin Last updated: April 8, 2015 at 12:47 Slideset 7: 1 Car Talk Puzzler You have a friend in a police state

More information

OpenSSL is a project comprising (1) a core library and (2) a toolkit. The core library offers an API for developers of secure applications.

OpenSSL is a project comprising (1) a core library and (2) a toolkit. The core library offers an API for developers of secure applications. 1 2 OpenSSL is a project comprising (1) a core library and (2) a toolkit. The core library offers an API for developers of secure applications. The toolkit offers a series of command-line tools to perform

More information

Cryptographic Techniques. Information Technologies for IPR Protections 2003/11/12 R107, CSIE Building

Cryptographic Techniques. Information Technologies for IPR Protections 2003/11/12 R107, CSIE Building Cryptographic Techniques Information Technologies for IPR Protections 2003/11/12 R107, CSIE Building Outline Data security Cryptography basics Cryptographic systems DES RSA C. H. HUANG IN CML 2 Cryptography

More information

Unit 3: Cryptography Fundamentals

Unit 3: Cryptography Fundamentals Unit 3: Cryptography Fundamentals Cryptography overview Symmetric Cryptography Fundamentals Asymmetric Cryptography concepts and fundamentals Hash Functions Message Authentication, MAC, HMAC Steganography

More information

Chapter 15: Security. Chapter 15: Security

Chapter 15: Security. Chapter 15: Security Chapter 15: Security Chapter 15: Security The Security Problem Program Threats System and Network Threats Cryptography as a Security Tool User Authentication Firewalling to Protect Systems and Networks

More information

Classical Encryption Techniques. CSS 322 Security and Cryptography

Classical Encryption Techniques. CSS 322 Security and Cryptography Classical Encryption Techniques CSS 322 Security and Cryptography Contents Terminology and Models Requirements, Services and Attacks Substitution Ciphers Caesar, Monoalphabetic, Polyalphabetic, One-time

More information

MARIA COLLEGE OF ENGINEERING AND TECHNOLOGY

MARIA COLLEGE OF ENGINEERING AND TECHNOLOGY MARIA COLLEGE OF ENGINEERING AND TECHNOLOGY DEPARTMENT OF INFORMATION TECHNOLOGY Subject Name : Cryptography and Network Security 1. Specify the four categories of security threads? Interruption Interception

More information

PASSWORDS & ENCRYPTION

PASSWORDS & ENCRYPTION PASSWORDS & ENCRYPTION Villanova University Department of Computing Sciences D. Justin Price Fall 2014 CRYPTOGRAPHY Hiding the meaning of a message from unintended recipients. Open source algorithms are

More information

Introduction to Symmetric Cryptography

Introduction to Symmetric Cryptography Introduction to Symmetric Cryptography Tingting Chen Cal Poly Pomona 1 Some slides are from Dr. Cliff Zou. www.cs.ucf.edu/~czou/cis3360-12/ch08-cryptoconcepts.ppt Basic Cryptography Private Key Cryptography

More information

Chapter 8 Web Security

Chapter 8 Web Security Chapter 8 Web Security Web security includes three parts: security of server, security of client, and network traffic security between a browser and a server. Security of server and security of client

More information

AIT 682: Network and Systems Security

AIT 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

Service Managed Gateway TM. Configuring IPSec VPN

Service Managed Gateway TM. Configuring IPSec VPN Service Managed Gateway TM Configuring IPSec VPN Issue 1.2 Date 12 November 2010 1: Introduction 1 Introduction... 3 1.1 What is a VPN?... 3 1.2 The benefits of an Internet-based VPN... 3 1.3 Tunnelling

More information

Introduction to Computer Security

Introduction to Computer Security Introduction to Computer Security Instructor: Mahadevan Gomathisankaran mgomathi@unt.edu CSCE 4550/5550, Fall 2009 Lecture 9 1 Announcements Assignment 1 Graded (out of 100) Max: 95 Min: 50 Mean: 77.33

More information

Overview. Public Key Algorithms I

Overview. Public Key Algorithms I Public Key Algorithms I Dr. Arjan Durresi Louisiana State University Baton Rouge, LA 70810 Durresi@csc.lsu.Edu These slides are available at: http://www.csc.lsu.edu/~durresi/csc4601-04/ Louisiana State

More information

CS 161 Computer Security

CS 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

Grenzen der Kryptographie

Grenzen der Kryptographie Microsoft Research Grenzen der Kryptographie Dieter Gollmann Microsoft Research 1 Summary Crypto does not solve security problems Crypto transforms security problems Typically, the new problems relate

More information

Textbook: Ahmet Burak Can Hacettepe University. Supplementary books:

Textbook: Ahmet Burak Can Hacettepe University. Supplementary books: Basic Ciphers Ahmet Burak Can Hacettepe University abc@hacettepe.edu.tr Books Textbook: Network Security: Private Communication in a Public World, 2nd Edition. C. Kaufman, R. Perlman, and M. Speciner,

More information

Princess Nora Bint Abdulrahman University College of computer and information sciences Networks department Networks Security (NET 536)

Princess Nora Bint Abdulrahman University College of computer and information sciences Networks department Networks Security (NET 536) Princess Nora Bint Abdulrahman University College of computer and information sciences Networks department Networks Security (NET 536) Prepared by Dr. Samia Chelloug E-mail: samia_chelloug@yahoo.fr Content

More information

Symmetric, Asymmetric, and One Way Technologies

Symmetric, Asymmetric, and One Way Technologies Symmetric, Asymmetric, and One Way Technologies Crypto Basics Ed Crowley Fall 2010 1 Topics: Symmetric & Asymmetric Technologies Kerckhoff s Principle Symmetric Crypto Overview Key management problem Attributes

More information

What did we talk about last time? Public key cryptography A little number theory

What 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 information

0/41. Alice Who? Authentication Protocols. Andreas Zeller/Stephan Neuhaus. Lehrstuhl Softwaretechnik Universität des Saarlandes, Saarbrücken

0/41. Alice Who? Authentication Protocols. Andreas Zeller/Stephan Neuhaus. Lehrstuhl Softwaretechnik Universität des Saarlandes, Saarbrücken 0/41 Alice Who? Authentication Protocols Andreas Zeller/Stephan Neuhaus Lehrstuhl Softwaretechnik Universität des Saarlandes, Saarbrücken The Menu 1/41 Simple Authentication Protocols The Menu 1/41 Simple

More information

F1 - Introduction. What is a Threat in a Communication Network? Security goals depending on the application environment 1

F1 - Introduction. What is a Threat in a Communication Network? Security goals depending on the application environment 1 What is a Threat in a Communication Network F1 - Introduction Abstract Definition: A threat in a communication network is any possible event or sequence of actions that might lead to a violation of one

More information

Public Key Cryptography

Public Key Cryptography Public Key Cryptography Giuseppe F. Italiano Universita` di Roma Tor Vergata italiano@disp.uniroma2.it Motivation Until early 70s, cryptography was mostly owned by government and military Symmetric cryptography

More information

10.1 Introduction 10.2 Asymmetric-Key Cryptography Asymmetric-Key Cryptography 10.3 RSA Cryptosystem

10.1 Introduction 10.2 Asymmetric-Key Cryptography Asymmetric-Key Cryptography 10.3 RSA Cryptosystem [Part 2] Asymmetric-Key Encipherment Asymmetric-Key Cryptography To distinguish between two cryptosystems: symmetric-key and asymmetric-key; To discuss the RSA cryptosystem; To introduce the usage of asymmetric-key

More information

Channel Coding and Cryptography Part II: Introduction to Cryptography

Channel Coding and Cryptography Part II: Introduction to Cryptography Channel Coding and Cryptography Part II: Introduction to Cryptography Prof. Dr.-Ing. habil. Andreas Ahrens Communications Signal Processing Group, University of Technology, Business and Design Email: andreas.ahrens@hs-wismar.de

More information

CPET 581 E-Commerce & Business Technologies. References

CPET 581 E-Commerce & Business Technologies. References CPET 581 E-Commerce & Business Technologies The E-Commerce Security Part 2 of 2 Paul I-Hai Lin, Professor http://www.etcs.ipfw.edu/~lin A Specialty Course for M.S. in Technology IT/Advanced Computer Applications

More information

Encrypted Phone Configuration File Setup

Encrypted Phone Configuration File Setup This chapter provides information about encrypted phone configuration files setup. After you configure security-related settings, the phone configuration file contains sensitive information, such as digest

More information

Some Stuff About Crypto

Some Stuff About Crypto Some Stuff About Crypto Adrian Frith Laboratory of Foundational Aspects of Computer Science Department of Mathematics and Applied Mathematics University of Cape Town This work is licensed under a Creative

More information