Network Security. Computer Networking Lecture 08. March 19, HKU SPACE Community College. HKU SPACE CC CN Lecture 08 1/23
|
|
- Alfred Crawford
- 8 years ago
- Views:
Transcription
1 Network Security Computer Networking Lecture 08 HKU SPACE Community College March 19, 2012 HKU SPACE CC CN Lecture 08 1/23
2 Outline Introduction Cryptography Algorithms Secret Key Algorithm Message Digest Public Key Cryptography Security Protocols Authentication Algorithms Message Integrity Protocols Remaining Issues HKU SPACE CC CN Lecture 08 2/23
3 Introduction Some expected network security services: Secrecy (or confidentiality): Prevent others from reading information shared between two participants. Authentication: Verifying someone s identity. Message integrity: Assure that the message received has not be altered after it was generated. Nonrepudiation: A sender should not be able to falsely deny later that he sent a message. Most of the security services require cryptographic tools as building blocks. Regarding the usage of cryptographic tools, there are two approaches: Keep the cryptographic algorithm (method) secret. (The preferred one) The cryptographic algorithm is not a secret, but the key is. HKU SPACE CC CN Lecture 08 3/23
4 Introduction (Cont d) The scope of the security issues (from networking point of view): Concern mainly the communication between two parties. Concern attacks against protocols, not those against cryptographic algorithms or cryptographic techniques used to implement the algorithms. Types of attacks against protocols: Passive attacks (eavesdropping), e.g., ciphertext-only attacks Active attacks, e.g., pretend to be someone else, introduce new messages in the protocol, delete existing messages, substituting one message for another, replay old messages, etc. HKU SPACE CC CN Lecture 08 4/23
5 Cryptography Algorithms One kind of cryptography algorithms is to process original data into some unintelligible form. The process is called encryption and the recovery of the original data is called decryption. The idea of encryption plaintext encryption ciphertext decryption plaintext Another kind of cryptography algorithms is to produce a unique piece data (signature) based on some given data. HKU SPACE CC CN Lecture 08 5/23
6 Cryptography Algorithms (Cont d) Requirements of the algorithms are: to keep the key secret is enough to ensure the privacy of the data; to be able to prevent the attacker from deducing the key, either by making the algorithm complicated (DES) making the algorithm be one-way (MD5) Common cryptography algorithms are: Secret key algorithms: Data Encryption Standard (DES) International Data Encryption Algorithm (IDEA) Public key algorithm: RSA Message digest: MD5 (also call cryptographic checksum) HKU SPACE CC CN Lecture 08 6/23
7 Secret Key (Symmetric) Cryptography Given: Alice and Bob agree on a cryptosystem. Alice and Bob agree on a key (secret). Encryption and decryption using the key. M E K (M) D K (E K (M)) M Problems: Keys must be distributed in secret. Compromising of keys means compromising all aspects of security. Number of keys is not scalable to the user population size. HKU SPACE CC CN Lecture 08 7/23
8 Secret Key (Symmetric) Cryptography (Cont d) Example: an 64-bit DES (Data Encryption Standard) Alice and Bob use the same algorithm and the same key to encrypt and decrypt. The only approach to attack is to search the entire key space. When more than 64 bits are required, use a cipher block chaining (CBC). The ciphertext for block i is XORed with the plaintext for block i+1 before running it through DES. An initialization vector (IV) is used in lieu of the nonexisting block 0. This number is randomly generated by a sender and it is sent along with the encrypted message. Triple-DES, i.e., encrypt the data three times. HKU SPACE CC CN Lecture 08 8/23
9 Secret Key (Symmetric) Cryptography (Cont d) Figure: Outline of DES. HKU SPACE CC CN Lecture 08 9/23
10 Secret Key (Symmetric) Cryptography (Cont d) Figure: CBC for large messages. HKU SPACE CC CN Lecture 08 10/23
11 Message Digest (Cryptographic Checksum) Message digest is a technique which can be used to verify whether a message has been malicious changed during the transmission (integrity). Message digest uses one-way hash functions as its fundamental building block. One-way functions are relatively easy to compute (given x, compute f (x)), but significantly harder to reverse (given f (x), compute x) For example, given integers x and y, it is easy to compute the product of x and y but hard to factorize a large integer. Given a cryptographic checksum for a message, it is not computationally feasible to find two messages that hash to the same cryptographic checksum. Example: MD5 HKU SPACE CC CN Lecture 08 11/23
12 Message Digest (Cryptographic Checksum) (Cont d) Figure: Outline of MD5. HKU SPACE CC CN Lecture 08 12/23
13 Public Key (Asymmetric) Cryptography In this method, two keys are used: a private key and a public key. It is computationally hard to deduce the private key from the public key. In the secrecy service, the encryption is done by using the public key and the decryption is done by using the private key. M E pub (M) D pri (E pub (M)) M Mathematically, the process bases on one-way functions. The public-key algorithm is slow. Symmetric algorithms are at least 1000 times faster. HKU SPACE CC CN Lecture 08 13/23
14 Public Key Cryptography - RSA RSA stands for Rivest, Shamir and Adleman. They are the inventors of the algorithm. The algorithm s outline goes as follows: Choose two large prime numbers p and q. Multiply p and q together to get n. Choose the encryption key e, such that e and (p 1) (q 1) are relatively prime. Compute decryption key d such that d =e 1 mod ((p 1) (q 1)). Construct private key as (e, n). Construct public key as (d, n). Discard (do not disclose) original primes p and q. To encrypt: c = m e mod n. To decrypt: m = c d mod n. Example: p = 3, q = 5, and plaintext = 9. HKU SPACE CC CN Lecture 08 14/23
15 Security Protocols Using the cryptography algorithms, we can design protocols to provide different security services. For the secrecy service, the secret key and the public key algorithms can be used. For the authentication service, we introduce here three protocols: two based on secret key algorithms and the other on public key algorithms. For the integrity, we also introduce three protocols. Besides the permanent keys, in a protocol, sometimes, the two participants may also establish session keys for ensuring the privacy between their communication. HKU SPACE CC CN Lecture 08 15/23
16 Authentication Algorithm (1) Assumption: both client and server already share a secret key. Approach: Each side generate a random number encrypted with the secret key. See whether the other side can decrypt it. Successful if CHK = SHK (client and server handshaking keys) SK: Session key HKU SPACE CC CN Lecture 08 16/23
17 Authentication Algorithm (1) Figure: Three-way handshake. HKU SPACE CC CN Lecture 08 17/23
18 Authentication Algorithm (2) This approach is based on a trusted third party (authentication server). Assumptions: A shares a secret key with S, and so is B with S. Notations in the messages: A, B: The participants identities T: Timestamp L: Lifetime K: Session key for A and B KA, KB: A s secret key shared with S and B s secret key shared with S, respectively. HKU SPACE CC CN Lecture 08 18/23
19 Authentication Algorithm (2) Figure: Trusted third party. HKU SPACE CC CN Lecture 08 19/23
20 Authentication Algorithm (3) Assumptions: Public key algorithm is used. A picks a random number and encrypts it with B s public key. B does the same to A. Figure: Public key authentication. HKU SPACE CC CN Lecture 08 20/23
21 Message Integrity Protocols Digital Signature Using RSA special case of a message integrity where the code can only have been generated by one participant, compute signature with private key and verify with public key. Keyed MD5 sender: m + MD5(m + k) + E(k, private); receiver: recovers random key using the sender s public key then applies MD5 to the concatenation of this random key message. MD5 with RSA signature sender: m + E(MD5(m), private); receiver: decrypts signature with sender s public key then compares result with MD5 checksum sent with message. HKU SPACE CC CN Lecture 08 21/23
22 Remaining Issues For the private key approach, how does a pair of participants generates and manages their shared secret key? Use RSA key exchange with digital signatures. Diffie-Hellman key exchange For the public key approach, how can one obtain another s true public key or how can one reliably advertise one s public key to others? Digital certificates Certification authority (a trusted third party approach) HKU SPACE CC CN Lecture 08 22/23
23 Acknowledgments Part of this slide set is referenced, prepared or/and extracted from the books: Computer Networks - A Systems Approach and the book Routing in the Internet. Also, some images and information are sourced from the Internet. This set of slides is for teaching purpose only. HKU SPACE CC CN Lecture 08 23/23
CSE/EE 461 Lecture 23
CSE/EE 461 Lecture 23 Network Security David Wetherall djw@cs.washington.edu Last Time Naming Application Presentation How do we name hosts etc.? Session Transport Network Domain Name System (DNS) Data
More informationSecurity. Friends and Enemies. Overview Plaintext Cryptography functions. Secret Key (DES) Symmetric Key
Friends and Enemies Security Outline Encryption lgorithms Protocols Message Integrity Protocols Key Distribution Firewalls Figure 7.1 goes here ob, lice want to communicate securely Trudy, the intruder
More informationCRYPTOGRAPHY IN NETWORK SECURITY
ELE548 Research Essays CRYPTOGRAPHY IN NETWORK SECURITY AUTHOR: SHENGLI LI INSTRUCTOR: DR. JIEN-CHUNG LO Date: March 5, 1999 Computer network brings lots of great benefits and convenience to us. We can
More informationCIS 6930 Emerging Topics in Network Security. Topic 2. Network Security Primitives
CIS 6930 Emerging Topics in Network Security Topic 2. Network Security Primitives 1 Outline Absolute basics Encryption/Decryption; Digital signatures; D-H key exchange; Hash functions; Application of hash
More informationNetwork Security. Security Attacks. Normal flow: Interruption: 孫 宏 民 hmsun@cs.nthu.edu.tw Phone: 03-5742968 國 立 清 華 大 學 資 訊 工 程 系 資 訊 安 全 實 驗 室
Network Security 孫 宏 民 hmsun@cs.nthu.edu.tw Phone: 03-5742968 國 立 清 華 大 學 資 訊 工 程 系 資 訊 安 全 實 驗 室 Security Attacks Normal flow: sender receiver Interruption: Information source Information destination
More informationSecurity. Contents. S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 1
Contents Security requirements Public key cryptography Key agreement/transport schemes Man-in-the-middle attack vulnerability Encryption. digital signature, hash, certification Complete security solutions
More informationChapter 7: Network security
Chapter 7: Network security Foundations: what is security? cryptography authentication message integrity key distribution and certification Security in practice: application layer: secure e-mail transport
More informationLecture 9: Application of Cryptography
Lecture topics Cryptography basics Using SSL to secure communication links in J2EE programs Programmatic use of cryptography in Java Cryptography basics Encryption Transformation of data into a form that
More informationCSCE 465 Computer & Network Security
CSCE 465 Computer & Network Security Instructor: Dr. Guofei Gu http://courses.cse.tamu.edu/guofei/csce465/ Public Key Cryptogrophy 1 Roadmap Introduction RSA Diffie-Hellman Key Exchange Public key and
More informationCS 758: Cryptography / Network Security
CS 758: Cryptography / Network Security offered in the Fall Semester, 2003, by Doug Stinson my office: DC 3122 my email address: dstinson@uwaterloo.ca my web page: http://cacr.math.uwaterloo.ca/~dstinson/index.html
More informationSECURITY IN NETWORKS
SECURITY IN NETWORKS GOALS Understand principles of network security: Cryptography and its many uses beyond confidentiality Authentication Message integrity Security in practice: Security in application,
More informationCryptosystems. Bob wants to send a message M to Alice. Symmetric ciphers: Bob and Alice both share a secret key, K.
Cryptosystems Bob wants to send a message M to Alice. Symmetric ciphers: Bob and Alice both share a secret key, K. C= E(M, K), Bob sends C Alice receives C, M=D(C,K) Use the same key to decrypt. Public
More informationCS 348: Computer Networks. - Security; 30 th - 31 st Oct 2012. Instructor: Sridhar Iyer IIT Bombay
CS 348: Computer Networks - Security; 30 th - 31 st Oct 2012 Instructor: Sridhar Iyer IIT Bombay Network security Security Plan (RFC 2196) Identify assets Determine threats Perform risk analysis Implement
More informationChapter 11 Security+ Guide to Network Security Fundamentals, Third Edition Basic Cryptography
Chapter 11 Security+ Guide to Network Security Fundamentals, Third Edition Basic Cryptography What Is Steganography? Steganography Process of hiding the existence of the data within another file Example:
More informationOverview of Cryptographic Tools for Data Security. Murat Kantarcioglu
UT DALLAS Erik Jonsson School of Engineering & Computer Science Overview of Cryptographic Tools for Data Security Murat Kantarcioglu Pag. 1 Purdue University Cryptographic Primitives We will discuss the
More informationOverview of Public-Key Cryptography
CS 361S Overview of Public-Key Cryptography Vitaly Shmatikov slide 1 Reading Assignment Kaufman 6.1-6 slide 2 Public-Key Cryptography public key public key? private key Alice Bob Given: Everybody knows
More informationComputer Networks. Network Security and Ethics. Week 14. College of Information Science and Engineering Ritsumeikan University
Computer Networks Network Security and Ethics Week 14 College of Information Science and Engineering Ritsumeikan University Security Intro for Admins l Network administrators can break security into two
More informationNetwork Security. Abusayeed Saifullah. CS 5600 Computer Networks. These slides are adapted from Kurose and Ross 8-1
Network Security Abusayeed Saifullah CS 5600 Computer Networks These slides are adapted from Kurose and Ross 8-1 Public Key Cryptography symmetric key crypto v requires sender, receiver know shared secret
More informationNetwork Security. HIT Shimrit Tzur-David
Network Security HIT Shimrit Tzur-David 1 Goals: 2 Network Security Understand principles of network security: cryptography and its many uses beyond confidentiality authentication message integrity key
More informationLukasz Pater CMMS Administrator and Developer
Lukasz Pater CMMS Administrator and Developer EDMS 1373428 Agenda Introduction Why do we need asymmetric ciphers? One-way functions RSA Cipher Message Integrity Examples Secure Socket Layer Single Sign
More informationNetwork Security (2) CPSC 441 Department of Computer Science University of Calgary
Network Security (2) CPSC 441 Department of Computer Science University of Calgary 1 Friends and enemies: Alice, Bob, Trudy well-known in network security world Bob, Alice (lovers!) want to communicate
More informationNetwork Security. Gaurav Naik Gus Anderson. College of Engineering. Drexel University, Philadelphia, PA. Drexel University. College of Engineering
Network Security Gaurav Naik Gus Anderson, Philadelphia, PA Lectures on Network Security Feb 12 (Today!): Public Key Crypto, Hash Functions, Digital Signatures, and the Public Key Infrastructure Feb 14:
More informationWhat is network security?
Network security Network Security Srinidhi Varadarajan Foundations: what is security? cryptography authentication message integrity key distribution and certification Security in practice: application
More information7! Cryptographic Techniques! A Brief Introduction
7! Cryptographic Techniques! A Brief Introduction 7.1! Introduction to Cryptography! 7.2! Symmetric Encryption! 7.3! Asymmetric (Public-Key) Encryption! 7.4! Digital Signatures! 7.5! Public Key Infrastructures
More informationLecture 9 - Network Security TDTS41-2006 (ht1)
Lecture 9 - Network Security TDTS41-2006 (ht1) Prof. Dr. Christoph Schuba Linköpings University/IDA Schuba@IDA.LiU.SE Reading: Office hours: [Hal05] 10.1-10.2.3; 10.2.5-10.7.1; 10.8.1 9-10am on Oct. 4+5,
More informationChapter 10. Network Security
Chapter 10 Network Security 10.1. Chapter 10: Outline 10.1 INTRODUCTION 10.2 CONFIDENTIALITY 10.3 OTHER ASPECTS OF SECURITY 10.4 INTERNET SECURITY 10.5 FIREWALLS 10.2 Chapter 10: Objective We introduce
More informationAn Introduction to Cryptography as Applied to the Smart Grid
An Introduction to Cryptography as Applied to the Smart Grid Jacques Benoit, Cooper Power Systems Western Power Delivery Automation Conference Spokane, Washington March 2011 Agenda > Introduction > Symmetric
More informationPrinciples of Network Security
he Network Security Model Bob and lice want to communicate securely. rudy (the adversary) has access to the channel. lice channel data, control s Bob Kai Shen data secure sender secure receiver data rudy
More informationAn Introduction to Cryptography and Digital Signatures
An Introduction to Cryptography and Digital Signatures Author: Ian Curry March 2001 Version 2.0 Copyright 2001-2003 Entrust. All rights reserved. Cryptography The concept of securing messages through
More informationMessage authentication and. digital signatures
Message authentication and " Message authentication digital signatures verify that the message is from the right sender, and not modified (incl message sequence) " Digital signatures in addition, non!repudiation
More informationComputer Networks 1 (Mạng Máy Tính 1) Lectured by: Dr. Phạm Trần Vũ MEng. Nguyễn CaoĐạt
Computer Networks 1 (Mạng Máy Tính 1) Lectured by: Dr. Phạm Trần Vũ MEng. Nguyễn CaoĐạt 1 Lecture 11: Network Security Reference: Chapter 8 - Computer Networks, Andrew S. Tanenbaum, 4th Edition, Prentice
More informationContent Teaching Academy at James Madison University
Content Teaching Academy at James Madison University 1 2 The Battle Field: Computers, LANs & Internetworks 3 Definitions Computer Security - generic name for the collection of tools designed to protect
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. # 02 Overview on Modern Cryptography
More information1720 - Forward Secrecy: How to Secure SSL from Attacks by Government Agencies
1720 - Forward Secrecy: How to Secure SSL from Attacks by Government Agencies Dave Corbett Technical Product Manager Implementing Forward Secrecy 1 Agenda Part 1: Introduction Why is Forward Secrecy important?
More informationHow encryption works to provide confidentiality. How hashing works to provide integrity. How digital signatures work to provide authenticity and
How encryption works to provide confidentiality. How hashing works to provide integrity. How digital signatures work to provide authenticity and non-repudiation. How to obtain a digital certificate. Installing
More informationOutline. CSc 466/566. Computer Security. 8 : Cryptography Digital Signatures. Digital Signatures. Digital Signatures... Christian Collberg
Outline CSc 466/566 Computer Security 8 : Cryptography Digital Signatures Version: 2012/02/27 16:07:05 Department of Computer Science University of Arizona collberg@gmail.com Copyright c 2012 Christian
More informationNetwork Security [2] Plain text Encryption algorithm Public and private key pair Cipher text Decryption algorithm. See next slide
Network Security [2] Public Key Encryption Also used in message authentication & key distribution Based on mathematical algorithms, not only on operations over bit patterns (as conventional) => much overhead
More informationCryptographic hash functions and MACs Solved Exercises for Cryptographic Hash Functions and MACs
Cryptographic hash functions and MACs Solved Exercises for Cryptographic Hash Functions and MACs Enes Pasalic University of Primorska Koper, 2014 Contents 1 Preface 3 2 Problems 4 2 1 Preface This is a
More informationCommon security requirements Basic security tools. Example. Secret-key cryptography Public-key cryptography. Online shopping with Amazon
1 Common security requirements Basic security tools Secret-key cryptography Public-key cryptography Example Online shopping with Amazon 2 Alice credit card # is xxxx Internet What could the hacker possibly
More informationApplication Layer (1)
Application Layer (1) Functionality: providing applications (e-mail, www, USENET etc) providing support protocols to allow the real applications to function properly security comprising a large number
More informationProperties of Secure Network Communication
Properties of Secure Network Communication Secrecy: Only the sender and intended receiver should be able to understand the contents of the transmitted message. Because eavesdroppers may intercept the message,
More informationModule 7 Security CS655! 7-1!
Module 7 Security CS655! 7-1! 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
More informationOverview of CSS SSL. SSL Cryptography Overview CHAPTER
CHAPTER 1 Secure Sockets Layer (SSL) is an application-level protocol that provides encryption technology for the Internet, ensuring secure transactions such as the transmission of credit card numbers
More informationCSC474/574 - Information Systems Security: Homework1 Solutions Sketch
CSC474/574 - Information Systems Security: Homework1 Solutions Sketch February 20, 2005 1. Consider slide 12 in the handout for topic 2.2. Prove that the decryption process of a one-round Feistel cipher
More informationCryptography & Digital Signatures
Cryptography & Digital Signatures CS 594 Special Topics/Kent Law School: Computer and Network Privacy and Security: Ethical, Legal, and Technical Consideration Prof. Sloan s Slides, 2007, 2008 Robert H.
More informationPGP (Pretty Good Privacy) INTRODUCTION ZHONG ZHAO
PGP (Pretty Good Privacy) INTRODUCTION ZHONG ZHAO In The Next 15 Minutes, You May Know What is PGP? Why using PGP? What can it do? How did it evolve? How does it work? How to work it? What s its limitation?
More informationPublic Key Cryptography Overview
Ch.20 Public-Key Cryptography and Message Authentication I will talk about it later in this class Final: Wen (5/13) 1630-1830 HOLM 248» give you a sample exam» Mostly similar to homeworks» no electronic
More informationFinal Exam. IT 4823 Information Security Administration. Rescheduling Final Exams. Kerberos. Idea. Ticket
IT 4823 Information Security Administration Public Key Encryption Revisited April 5 Notice: This session is being recorded. Lecture slides prepared by Dr Lawrie Brown for Computer Security: Principles
More informationThe Mathematics of the RSA Public-Key Cryptosystem
The Mathematics of the RSA Public-Key Cryptosystem Burt Kaliski RSA Laboratories ABOUT THE AUTHOR: Dr Burt Kaliski is a computer scientist whose involvement with the security industry has been through
More informationPart 2 D(E(M, K),K ) E(M, K) E(M, K) Plaintext M. Plaintext M. Decrypt with private key. Encrypt with public key. Ciphertext
Part 2 Plaintext M Encrypt with public key E(M, K) Ciphertext Plaintext M D(E(M, K),K ) Decrypt with private key E(M, K) Public and private key related mathematically Public key can be published; private
More informationOverview. SSL Cryptography Overview CHAPTER 1
CHAPTER 1 Note The information in this chapter applies to both the ACE module and the ACE appliance unless otherwise noted. The features in this chapter apply to IPv4 and IPv6 unless otherwise noted. Secure
More informationCryptography and Network Security
Cryptography and Network Security Spring 2012 http://users.abo.fi/ipetre/crypto/ Lecture 9: Authentication protocols, digital signatures Ion Petre Department of IT, Åbo Akademi University 1 Overview of
More informationComputer Security: Principles and Practice
Computer Security: Principles and Practice Chapter 20 Public-Key Cryptography and Message Authentication First Edition by William Stallings and Lawrie Brown Lecture slides by Lawrie Brown Public-Key Cryptography
More informationSoftware Tool for Implementing RSA Algorithm
Software Tool for Implementing RSA Algorithm Adriana Borodzhieva, Plamen Manoilov Rousse University Angel Kanchev, Rousse, Bulgaria Abstract: RSA is one of the most-common used algorithms for public-key
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 Introduction to Cryptography What is cryptography?
More informationLecture 6 - Cryptography
Lecture 6 - Cryptography CSE497b - Spring 2007 Introduction Computer and Network Security Professor Jaeger www.cse.psu.edu/~tjaeger/cse497b-s07 Question 2 Setup: Assume you and I don t know anything about
More informationModule 8. Network Security. Version 2 CSE IIT, Kharagpur
Module 8 Network Security Lesson 2 Secured Communication Specific Instructional Objectives On completion of this lesson, the student will be able to: State various services needed for secured communication
More informationSFWR ENG 4C03 - Computer Networks & Computer Security
KEY MANAGEMENT SFWR ENG 4C03 - Computer Networks & Computer Security Researcher: Jayesh Patel Student No. 9909040 Revised: April 4, 2005 Introduction Key management deals with the secure generation, distribution,
More informationSecure Network Communication Part II II Public Key Cryptography. Public Key Cryptography
Kommunikationssysteme (KSy) - Block 8 Secure Network Communication Part II II Public Key Cryptography Dr. Andreas Steffen 2000-2001 A. Steffen, 28.03.2001, KSy_RSA.ppt 1 Secure Key Distribution Problem
More informationNetwork Security. Security. Security Services. Crytographic algorithms. privacy authenticity Message integrity. Public key (RSA) Message digest (MD5)
Network Security Security Crytographic algorithms Security Services Secret key (DES) Public key (RSA) Message digest (MD5) privacy authenticity Message integrity Secret Key Encryption Plain text Plain
More informationInformation Security
Information Security Dr. Vedat Coşkun Malardalen September 15th, 2009 08:00 10:00 vedatcoskun@isikun.edu.tr www.isikun.edu.tr/~vedatcoskun What needs to be secured? With the rapid advances in networked
More informationSymmetric Key cryptosystem
SFWR C03: Computer Networks and Computer Security Mar 8-11 200 Lecturer: Kartik Krishnan Lectures 22-2 Symmetric Key cryptosystem Symmetric encryption, also referred to as conventional encryption or single
More informationClient Server Registration Protocol
Client Server Registration Protocol The Client-Server protocol involves these following steps: 1. Login 2. Discovery phase User (Alice or Bob) has K s Server (S) has hash[pw A ].The passwords hashes are
More informationPart I. Universität Klagenfurt - IWAS Multimedia Kommunikation (VK) M. Euchner; Mai 2001. Siemens AG 2001, ICN M NT
Part I Contents Part I Introduction to Information Security Definition of Crypto Cryptographic Objectives Security Threats and Attacks The process Security Security Services Cryptography Cryptography (code
More informationSecure Socket Layer. Introduction Overview of SSL What SSL is Useful For
Secure Socket Layer Secure Socket Layer Introduction Overview of SSL What SSL is Useful For Introduction Secure Socket Layer (SSL) Industry-standard method for protecting web communications. - Data encryption
More informationCryptography and Network Security Chapter 9
Cryptography and Network Security Chapter 9 Fifth Edition by William Stallings Lecture slides by Lawrie Brown (with edits by RHB) Chapter 9 Public Key Cryptography and RSA Every Egyptian received two names,
More information159.334 Computer Networks. Network Security 1. Professor Richard Harris School of Engineering and Advanced Technology
Network Security 1 Professor Richard Harris School of Engineering and Advanced Technology Presentation Outline Overview of Identification and Authentication The importance of identification and Authentication
More informationPublic Key Cryptography. c Eli Biham - March 30, 2011 258 Public Key Cryptography
Public Key Cryptography c Eli Biham - March 30, 2011 258 Public Key Cryptography Key Exchange All the ciphers mentioned previously require keys known a-priori to all the users, before they can encrypt
More informationCPSC 467b: Cryptography and Computer Security
CPSC 467b: Cryptography and Computer Security Michael J. Fischer Lecture 1 January 9, 2012 CPSC 467b, Lecture 1 1/22 Course Overview Symmetric Cryptography CPSC 467b, Lecture 1 2/22 Course Overview CPSC
More informationNetwork Security Technology Network Management
COMPUTER NETWORKS Network Security Technology Network Management Source Encryption E(K,P) Decryption D(K,C) Destination The author of these slides is Dr. Mark Pullen of George Mason University. Permission
More informationIT Networks & Security CERT Luncheon Series: Cryptography
IT Networks & Security CERT Luncheon Series: Cryptography Presented by Addam Schroll, IT Security & Privacy Analyst 1 Outline History Terms & Definitions Symmetric and Asymmetric Algorithms Hashing PKI
More informationChap. 1: Introduction
Chap. 1: Introduction Introduction Services, Mechanisms, and Attacks The OSI Security Architecture Cryptography 1 1 Introduction Computer Security the generic name for the collection of tools designed
More informationNetwork Security. Abusayeed Saifullah. CS 5600 Computer Networks. These slides are adapted from Kurose and Ross 8-1
Network Security Abusayeed Saifullah CS 5600 Computer Networks These slides are adapted from Kurose and Ross 8-1 Goals v understand principles of network security: cryptography and its many uses beyond
More informationAuthentication Application
Authentication Application KERBEROS In an open distributed environment servers to be able to restrict access to authorized users to be able to authenticate requests for service a workstation cannot be
More informationCryptography and Network Security Department of Computer Science and Engineering Indian Institute of Technology Kharagpur
Cryptography and Network Security Department of Computer Science and Engineering Indian Institute of Technology Kharagpur Module No. # 01 Lecture No. # 05 Classic Cryptosystems (Refer Slide Time: 00:42)
More informationNetwork Security #10. Overview. Encryption Authentication Message integrity Key distribution & Certificates Secure Socket Layer (SSL) IPsec
Network Security #10 Parts modified from Computer Networking: A Top Down Approach Featuring the Internet, 2nd edition. Jim Kurose, Keith Ross, Addison-Wesley, 2002. 1 Overview Encryption Authentication
More informationPublic Key (asymmetric) Cryptography
Public-Key Cryptography UNIVERSITA DEGLI STUDI DI PARMA Dipartimento di Ingegneria dell Informazione Public Key (asymmetric) Cryptography Luca Veltri (mail.to: luca.veltri@unipr.it) Course of Network Security,
More informationSavitribai Phule Pune University
Savitribai Phule Pune University Centre for Information and Network Security Course: Introduction to Cyber Security / Information Security Module : Pre-requisites in Information and Network Security Chapter
More informationMathematical Model Based Total Security System with Qualitative and Quantitative Data of Human
Int Jr of Mathematics Sciences & Applications Vol3, No1, January-June 2013 Copyright Mind Reader Publications ISSN No: 2230-9888 wwwjournalshubcom Mathematical Model Based Total Security System with Qualitative
More informationCUNSHENG DING HKUST, Hong Kong. Computer Security. Computer Security. Cunsheng DING, HKUST COMP4631
Cunsheng DING, HKUST Lecture 08: Key Management for One-key Ciphers Topics of this Lecture 1. The generation and distribution of secret keys. 2. A key distribution protocol with a key distribution center.
More informationMathematics of Internet Security. Keeping Eve The Eavesdropper Away From Your Credit Card Information
The : Keeping Eve The Eavesdropper Away From Your Credit Card Information Department of Mathematics North Dakota State University 16 September 2010 Science Cafe Introduction Disclaimer: is not an internet
More informationLecture G1 Privacy, Security, and Cryptography. Computing and Art : Nature, Power, and Limits CC 3.12: Fall 2007
Lecture G1 Privacy, Security, and Cryptography Computing and Art : Nature, Power, and Limits CC 3.12: Fall 2007 Functionalia Instructor Chipp Jansen, chipp@sci.brooklyn.cuny.edu Course Web Page http://www.sci.brooklyn.cuny.edu/~chipp/cc3.12/
More informationHow To Encrypt Data With Encryption
USING ENCRYPTION TO PROTECT SENSITIVE INFORMATION Commonwealth Office of Technology Security Month Seminars Alternate Title? Boy, am I surprised. The Entrust guy who has mentioned PKI during every Security
More informationCompter Networks Chapter 9: Network Security
Goals of this chapter Compter Networks Chapter 9: Network Security Give a brief glimpse of security in communication networks Basic goals and mechanisms Holger Karl Slide set: Günter Schäfer, TU Ilmenau
More informationAC76/AT76 CRYPTOGRAPHY & NETWORK SECURITY DEC 2014
Q.2a. Define Virus. What are the four phases of Viruses? In addition, list out the types of Viruses. A virus is a piece of software that can infect other programs by modifying them; the modification includes
More informationAN IMPLEMENTATION OF HYBRID ENCRYPTION-DECRYPTION (RSA WITH AES AND SHA256) FOR USE IN DATA EXCHANGE BETWEEN CLIENT APPLICATIONS AND WEB SERVICES
HYBRID RSA-AES ENCRYPTION FOR WEB SERVICES AN IMPLEMENTATION OF HYBRID ENCRYPTION-DECRYPTION (RSA WITH AES AND SHA256) FOR USE IN DATA EXCHANGE BETWEEN CLIENT APPLICATIONS AND WEB SERVICES Kalyani Ganesh
More informationMessage Authentication Codes
2 MAC Message Authentication Codes : and Cryptography Sirindhorn International Institute of Technology Thammasat University Prepared by Steven Gordon on 28 October 2013 css322y13s2l08, Steve/Courses/2013/s2/css322/lectures/mac.tex,
More informationNetwork Security CS 5490/6490 Fall 2015 Lecture Notes 8/26/2015
Network Security CS 5490/6490 Fall 2015 Lecture Notes 8/26/2015 Chapter 2: Introduction to Cryptography What is cryptography? It is a process/art of mangling information in such a way so as to make it
More informationOutline. Computer Science 418. Digital Signatures: Observations. Digital Signatures: Definition. Definition 1 (Digital signature) Digital Signatures
Outline Computer Science 418 Digital Signatures Mike Jacobson Department of Computer Science University of Calgary Week 12 1 Digital Signatures 2 Signatures via Public Key Cryptosystems 3 Provable 4 Mike
More informationNetwork Security. Omer Rana
Network Security Omer Rana CM0255 Material from: Cryptography Components Sender Receiver Plaintext Encryption Ciphertext Decryption Plaintext Encryption algorithm: Plaintext Ciphertext Cipher: encryption
More informationSecurity and Authentication Primer
Security and Authentication Primer Manfred Jantscher and Peter H. Cole Auto-ID Labs White Paper WP-HARDWARE-025 Mr. Manfred Jantscher Visiting Master Student, School of Electrical and Electronics Engineering,
More informationCryptography: Authentication, Blind Signatures, and Digital Cash
Cryptography: Authentication, Blind Signatures, and Digital Cash Rebecca Bellovin 1 Introduction One of the most exciting ideas in cryptography in the past few decades, with the widest array of applications,
More informationSecurity vulnerabilities in the Internet and possible solutions
Security vulnerabilities in the Internet and possible solutions 1. Introduction The foundation of today's Internet is the TCP/IP protocol suite. Since the time when these specifications were finished in
More informationNETWORK SECURITY. Farooq Ashraf. Department of Computer Engineering King Fahd University of Petroleum and Minerals Dhahran 31261, Saudi Arabia
NETWORK SECURITY Farooq Ashraf Department of Computer Engineering King Fahd University of Petroleum and Minerals Dhahran 31261, Saudi Arabia O u t l i n e o f t h e P r e s e n t a t i o n What is Security
More informationA SOFTWARE COMPARISON OF RSA AND ECC
International Journal Of Computer Science And Applications Vol. 2, No. 1, April / May 29 ISSN: 974-13 A SOFTWARE COMPARISON OF RSA AND ECC Vivek B. Kute Lecturer. CSE Department, SVPCET, Nagpur 9975549138
More informationCryptography & Network Security
Cryptography & Network Security Lecture 1: Introduction & Overview 2002. 3. 27 chlim@sejong.ac.kr Common Terms(1) Cryptography: The study of mathematical techniques related to aspects of information security
More informationPublic Key Cryptography and RSA. Review: Number Theory Basics
Public Key Cryptography and RSA Murat Kantarcioglu Based on Prof. Ninghui Li s Slides Review: Number Theory Basics Definition An integer n > 1 is called a prime number if its positive divisors are 1 and
More informationCryptography and Network Security
Cryptography and Network Security Spring 2012 http://users.abo.fi/ipetre/crypto/ Lecture 1: Introduction Ion Petre Department of IT, Åbo Akademi University January 10, 2012 1 Motto Unfortunately, the technical
More informationChapter 8 Security. IC322 Fall 2014. Computer Networking: A Top Down Approach. 6 th edition Jim Kurose, Keith Ross Addison-Wesley March 2012
Chapter 8 Security IC322 Fall 2014 Computer Networking: A Top Down Approach 6 th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 All material copyright 1996-2012 J.F Kurose and K.W. Ross, All
More informationSPC5-CRYP-LIB. SPC5 Software Cryptography Library. Description. Features. SHA-512 Random engine based on DRBG-AES-128
SPC5 Software Cryptography Library Data brief SHA-512 Random engine based on DRBG-AES-128 RSA signature functions with PKCS#1v1.5 ECC (Elliptic Curve Cryptography): Key generation Scalar multiplication
More information