CS 758: Cryptography / Network Security


 Madeline White
 1 years ago
 Views:
Transcription
1 CS 758: Cryptography / Network Security offered in the Fall Semester, 2003, by Doug Stinson my office: DC 3122 my address: my web page: provides a link to the course web page lectures: Mondays and Wednesdays from 2:30 PM  4:00 PM in E Sept. 8,
2 Objectives/Prerequisites basic cryptography concerns secure communication between two parties, while in this course we are interested in cryptographic protocols in multiuser/network context there is no overlap with C&O 685 (Mathematics of PublicKey Cryptography), or with ECE 720 (Cryptographic Computations), or with ECE 710 (Sequence Design and Cryptography) prerequisites: a previous course in cryptography (e.g. C&O 487, Applied Cryptography) is helpful but not required background: basic complexity theory, elementary number theory, algebra (finite groups, finite fields, linear algebra), probability (random variables), combinatorics Sept. 8,
3 Course Requirements students grades will be based on assignments (4 or 5, about 70%) and a project (about 30%) the project will be a written project, possibly with a partner the project will involve preparing a report on a recent research paper on a topic related to the course material, or implementing and analyzing one or more protocols on a topic related to the course material Sept. 8,
4 Course Outline Review of cryptographic primitives and their applications to information security, and notions of cryptographic security. Discussion of publickey encryption, secretkey encryption, message authentication, signature schemes, and hash functions. Techniques for entity authentication. Passwords, challengeresponse, identification schemes (e.g., FiatShamir, GuillouQuisquater), general techniques for zeroknowledge proofs for NPcomplete languages. Protocols for key establishment, transport, agreement and maintenance. Online key distibution using a trusted server (Kerberos). Publickey techniques, including DiffieHellman key agreement, maninthemiddle attacks, STS and forward secrecy. Unconditionally secure key distribution, including the Blom scheme and combinatorial key distribution patterns. Sept. 8,
5 Course Outline (cont.) Cryptography in a multiuser setting. Secret sharing schemes (including Shamir threshold schemes and schemes for general access structures). Conference key distribution and broadcast encryption. Copyright protection techniques and tracing schemes. Publickey infrastructure. Models for managing public keys and certificates (X.509 certificates, certification authorities, trust models, certificate verification and revocation, etc.). Applications, including PGP, SSL and IPsec. Sept. 8,
6 Goals of Cryptography confidentiality Confidentiality (or secrecy) means that data cannot be understood by an unauthorized party. data integrity Data integrity means that data cannot be modified by an unauthorized party. data origin authentication Data origin authentication is achieved when it can be verified that data was transmitted by a particular source. entity authentication Entity authentication (or identification) refers to the verification of the identity of a person, computer or other device. Sept. 8,
7 Goals of Cryptography (cont.) nonrepudiation Nonrepudiation occurs when it is impossible for someone to deny having transmitted a message that, in fact, they did transmit. access control Access control refers to the restriction of electronic or physical access to authorized parties. anonymity Anonymity refers to the anonymous transmission of data, so that the origin cannot be determined. Sept. 8,
8 Cryptographic Tools encryption schemes Encryption schemes are used to achieve confidentiality. signature schemes Signature schemes are used to sign data. A signature helps to ensure data integrity and data origin authentication, and it can also provide nonrepudiation. message authentication codes A message authentication code provides data integrity. cryptographic hash functions A hash function is used to provide random, unpredictable redundancy in data. Sept. 8,
9 Cryptographic Tools (cont.) key agreement protocols A key agreement protocol is used to establish a common secret key known to two or more specified parties. Usually this key is to be subsequently used for another cryptographic purpose such as symmetrickey encryption or message authentication. identification schemes An identification scheme provides entity authentication. pseudorandom number generators Pseudorandom number generators expand a small, truly random, seed into a long string of bits that cannot be distinguished from random bits. Pseudorandom number generators are used in many cryptographic contexts, for example, in the generation of keys. Sept. 8,
10 Tools and their Usage of Keys A short summary of cryptographic tools and their usage of keys is provided in the following table. An X indicates that the given algorithm and key combination is feasible. keys scheme public/private? secret? no key? encryption scheme X X signature scheme MAC hash function key agreement scheme X X identification scheme X X X X X Sept. 8,
11 Secure Socket Layer client server I m Alice I m Bob, Inc. PK, sig CA (PK ) verify PK generate MS y = e PK (MS) K 1,K 2 = h(ms) MS = d PK (y) K 1,K 2 = h(ms) Sept. 8,
12 Cryptosystem A cryptosystem is a fivetuple (P, C, K, E, D), where the following conditions are satisfied: 1. P is a finite set of possible plaintexts 2. C is a finite set of possible ciphertexts 3. K, thekeyspace, is a finite set of possible keys 4. For each K K, thereisanencryption rule e K E and a corresponding decryption rule d K D. Eache K : P C and d K : C P are functions such that d K (e K (x)) = x for every plaintext element x P. Sept. 8,
13 Publickey vs Secretkey Cryptosystems in a secretkey cryptosystem, K is known to both Alice and Bob: Alice K Bob K y = e K (x) y x = d K (y) in a publickey cryptosystem, K is known only to Bob and e K is public: Alice e k y = e K (x) y Bob K x = d K (y) Sept. 8,
14 A SubstitutionPermutation Network x K 1 u 1 1 v S 1 S S 1 S w 1 K 2 u 2 S 2 S S 2 3 S 2 4 v 2 w 2 u 3 v 3 S 1 3 K 3 S 3 2 S 3 S w u 4 v 4 y 3 S 1 4 K 4 S 4 2 S 4 3 S 4 4 K 5 Sept. 8,
15 The Advanced Encryption Standard (AES) AES has a block length of 128 bits, and it supports key lengths of 128, 192 and 256 bits. The number of rounds, Nr, depends on the key length: Nr = 10 if the key length is 128 bits; Nr = 12 if the key length is 192 bits; and Nr = 14 if the key length is 256 bits. 1. Given a plaintext x, initialize State to be x and perform AddRoundKey, which xors the RoundKey with State. 2. For each of the first Nr 1 rounds, perform a substitution operation called SubBytes on State using an Sbox; perform a permutation ShiftRows on State; perform an operation MixColumns on State; andperformaddroundkey. 3. Perform SubBytes; perform ShiftRows; and perform AddRoundKey. 4. Define the ciphertext y to be State. Sept. 8,
16 AES States All operations in AES are byteoriented operations, and all variables used are considered to be formed from an appropriate number of bytes. The plaintext x consists of 16 bytes, denoted x 0,...,x 15. State is represented as a four by four array of bytes, initialized as follows: s 0,0 s 0,1 s 0,2 s 0,3 s 1,0 s 1,1 s 1,2 s 1,3 s 2,0 s 2,1 s 2,2 s 2,3 s 3,0 s 3,1 s 3,2 s 3,3 x 0 x 4 x 8 x 12 x 1 x 5 x 9 x 13 x 2 x 6 x 10 x 14 x 3 x 7 x 11 x 15 Sept. 8,
17 The Finite Field F 256 The operation SubBytes performs a substitution on each byte of State independently, which involves operations in the finite field F 2 8 = Z 2 [x]/(x 8 + x 4 + x 3 + x +1). Let BinaryToField convert a byte to a field element; and let FieldToBinary perform the inverse conversion. This conversion is done in the obvious way: the field element corresponds to the byte 7 a i x i i=0 where a i Z 2 for 0 i 7. a 7 a 6 a 5 a 4 a 3 a 2 a 1 a 0, Sept. 8,
18 SubBytes Algorithm: SubBytes(a 7 a 6 a 5 a 4 a 3 a 2 a 1 a 0 ) external FieldInv, BinaryToField, FieldToBinary z BinaryToField(a 7 a 6 a 5 a 4 a 3 a 2 a 1 a 0 ) if z 0 then z FieldInv(z) (a 7 a 6 a 5 a 4 a 3 a 2 a 1 a 0 ) FieldToBinary(z) (c 7 c 6 c 5 c 4 c 3 c 2 c 1 c 0 ) ( ) for i 0 to 7 do b i (a i + a i+4 + a i+5 + a i+6 + a i+7 + c i )mod2 return b 7 b 6 b 5 b 4 b 3 b 2 b 1 b 0 Sept. 8,
19 ShiftRows The operation ShiftRows acts on State as shown in the following diagram: s 0,0 s 0,1 s 0,2 s 0,3 s 1,0 s 1,1 s 1,2 s 1,3 s 2,0 s 2,1 s 2,2 s 2,3 s 3,0 s 3,1 s 3,2 s 3,3 s 0,0 s 0,1 s 0,2 s 0,3 s 1,1 s 1,2 s 1,3 s 1,0 s 2,2 s 2,3 s 2,0 s 2,1 s 3,3 s 3,0 s 3,1 s 3,2 Sept. 8,
20 MixColumns Algorithm: MixColumn(c) external FieldMult, BinaryToField, FieldToBinary for i 0 to 3 do t i BinaryToField(s i,c ) u 0 FieldMult(x, t 0 ) FieldMult(x +1,t 1 ) t 2 t 3 u 1 FieldMult(x, t 1 ) FieldMult(x +1,t 2 ) t 3 t 0 u 2 FieldMult(x, t 2 ) FieldMult(x +1,t 3 ) t 0 t 1 u 3 FieldMult(x, t 3 ) FieldMult(x +1,t 0 ) t 1 t 2 for i 0 to 3 do s i,c FieldToBinary(u i ) Sept. 8,
21 Modes of Operation ECB (electronic code book) mode corresponds to the naive use of a block cipher: given a sequence x 1 x 2 of plaintext blocks (each consisting of 128 bits, in the case of the AES), each x i is encrypted with the same key K, producing a string of ciphertext blocks, y 1 y 2. In CBC (cipher block chaining) mode, each ciphertext block y i is xored with the next plaintext block, x i+1, before being encrypted with the key K. More formally, we start with an initialization vector, denoted by IV, and define y 0 =IV. Then we construct y 1,y 2,..., using the rule i 1. y i = e K (y i 1 x i ), Sept. 8,
22 CBC Mode x 1 x 2 IV = y encrypt e K e K y 1 y 2 decrypt y 1 y 2 d K d K IV = y x 1 x 2 Sept. 8,
23 The RSA Publickey Cryptosystem Let n = pq, wherep and q are large primes. Let P = C = Z n,and define K = {(n, p, q, a, b) :ab 1(modφ(n))}. For K =(n, p, q, a, b), define e K (x) =x b mod n and d K (y) =y a mod n (x, y Z n ). The values n and b comprise the public key, and the values p, q and a form the private key. Sept. 8,
24 A Toy Example suppose Bob chooses primes p = 101 and q = 113 then n = and φ(n) = = suppose Bob chooses public encryption exponent b = 3533 then his private decryption exponent is a = b 1 mod = 6597 suppose Alice wants to encrypt the plaintext x = 9726 she will compute and send y to Bob y = mod = 5761 when Bob receives the ciphertext y = 5761, he computes x = mod = Sept. 8,
25 The Rabin Cryptosystem Let n = pq, wherep and q are primes. Let P = C = Z n, and define K = {(n, p, q)}. For K =(n, p, q), define e K (x) =x 2 mod n and d K (y) = y mod n. The value n is the public key, while p and q are the private key. Note: there are four square roots of y modulo n. Sept. 8,
26 A Toy Example suppose Bob chooses primes p =7andq =11 then the encryption function is e K (x) =x 2 mod 77 and the decryption function is d K (y) = y mod 77 suppose Alice encrypts the plaintext x =32tosendtoBob the ciphertext is y =32 2 mod 77 = 23 the four square roots of 23 modulo 77 are ±10, ±32 mod 77 the four possible plaintexts are x =10, 32, 45 and 67 Sept. 8,
Cryptosystems. 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 informationNetwork Security. Computer Networking Lecture 08. March 19, 2012. HKU SPACE Community College. HKU SPACE CC CN Lecture 08 1/23
Network Security Computer Networking Lecture 08 HKU SPACE Community College March 19, 2012 HKU SPACE CC CN Lecture 08 1/23 Outline Introduction Cryptography Algorithms Secret Key Algorithm Message Digest
More informationEXAM questions for the course TTM4135  Information Security May 2013. Part 1
EXAM questions for the course TTM4135  Information Security May 2013 Part 1 This part consists of 5 questions all from one common topic. The number of maximal points for every correctly answered question
More informationLecture 9  Network Security TDTS412006 (ht1)
Lecture 9  Network Security TDTS412006 (ht1) Prof. Dr. Christoph Schuba Linköpings University/IDA Schuba@IDA.LiU.SE Reading: Office hours: [Hal05] 10.110.2.3; 10.2.510.7.1; 10.8.1 910am on Oct. 4+5,
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 informationChapter 8. Network Security
Chapter 8 Network Security Cryptography Introduction to Cryptography Substitution Ciphers Transposition Ciphers OneTime Pads Two Fundamental Cryptographic Principles Need for Security Some people who
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; DH key exchange; Hash functions; Application of hash
More informationRef: [Mark Stamp] Chapter 4
Ref: [Mark Stamp] Chapter 4 309 310 311 312 Stream cipher could be an approximation of one time pad. In one time pad the key stream is supp 313 Advanced Encryption Standard (AES) has open design in contrast
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 Secret Key Cryptography Modes of operation Stream
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 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 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 DiffieHellman Key Exchange Public key and
More informationIntroduction to Cryptography CS 355
Introduction to Cryptography CS 355 Lecture 30 Digital Signatures CS 355 Fall 2005 / Lecture 30 1 Announcements Wednesday s lecture cancelled Friday will be guest lecture by Prof. Cristina Nita Rotaru
More informationCRYPTOGRAPHIC ALGORITHMS (AES, RSA)
CALIFORNIA STATE POLYTECHNIC UNIVERSITY, POMONA CRYPTOGRAPHIC ALGORITHMS (AES, RSA) A PAPER SUBMITTED TO PROFESSOR GILBERT S. YOUNG IN PARTIAL FULFILLMENT OF THE REQUIREMENT FOR THE COURSE CS530 : ADVANCED
More informationStream Ciphers. Example of Stream Decryption. Example of Stream Encryption. Real Cipher Streams. Terminology. Introduction to Modern Cryptography
Introduction to Modern Cryptography Lecture 2 Symmetric Encryption: Stream & Block Ciphers Stream Ciphers Start with a secret key ( seed ) Generate a keying stream ith bit/byte of keying stream is a function
More informationChapter 8. Cryptography SymmetricKey Algorithms. Digital Signatures Management of Public Keys Communication Security Authentication Protocols
Network Security Chapter 8 Cryptography SymmetricKey Algorithms PublicKey Algorithms Digital Signatures Management of Public Keys Communication Security Authentication Protocols Email Security Web Security
More informationCommon security requirements Basic security tools. Example. Secretkey cryptography Publickey cryptography. Online shopping with Amazon
1 Common security requirements Basic security tools Secretkey cryptography Publickey cryptography Example Online shopping with Amazon 2 Alice credit card # is xxxx Internet What could the hacker possibly
More informationSecurity. Contents. S72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 1
Contents Security requirements Public key cryptography Key agreement/transport schemes Maninthemiddle attack vulnerability Encryption. digital signature, hash, certification Complete security solutions
More informationApplied Cryptology. Ed Crowley
Applied Cryptology Ed Crowley 1 Basics Topics Basic Services and Operations Symmetric Cryptography Encryption and Symmetric Algorithms Asymmetric Cryptography Authentication, Nonrepudiation, and Asymmetric
More informationMidterm Exam Solutions CS161 Computer Security, Spring 2008
Midterm Exam Solutions CS161 Computer Security, Spring 2008 1. To encrypt a series of plaintext blocks p 1, p 2,... p n using a block cipher E operating in electronic code book (ECB) mode, each ciphertext
More informationTable of Contents. Bibliografische Informationen http://dnb.info/996514864. digitalisiert durch
1 Introduction to Cryptography and Data Security 1 1.1 Overview of Cryptology (and This Book) 2 1.2 Symmetric Cryptography 4 1.2.1 Basics 4 1.2.2 Simple Symmetric Encryption: The Substitution Cipher...
More informationCRYPTOGRAPHY IN NETWORK SECURITY
ELE548 Research Essays CRYPTOGRAPHY IN NETWORK SECURITY AUTHOR: SHENGLI LI INSTRUCTOR: DR. JIENCHUNG LO Date: March 5, 1999 Computer network brings lots of great benefits and convenience to us. We can
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 informationSecurity usually depends on the secrecy of the key, not the secrecy of the algorithm (i.e., the open design model!)
1 A cryptosystem has (at least) five ingredients: 1. 2. 3. 4. 5. Plaintext Secret Key Ciphertext Encryption algorithm Decryption algorithm Security usually depends on the secrecy of the key, not the secrecy
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 informationCryptography and Network Security: Summary
Cryptography and Network Security: Summary Timo Karvi 12.2013 Timo Karvi () Cryptography and Network Security: Summary 12.2013 1 / 17 Summary of the Requirements for the exam The advices are valid for
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 informationBasics of Cryptography
Basics of Cryptography What is Cryptography? Cryptography is an applied branch of mathematics In some situations it can be used to provide Confidentiality Integrity Authentication Authorization Nonrepudiation
More informationNetwork Security. Abusayeed Saifullah. CS 5600 Computer Networks. These slides are adapted from Kurose and Ross 81
Network Security Abusayeed Saifullah CS 5600 Computer Networks These slides are adapted from Kurose and Ross 81 Public Key Cryptography symmetric key crypto v requires sender, receiver know shared secret
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 (PublicKey) Encryption! 7.4! Digital Signatures! 7.5! Public Key Infrastructures
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 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 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 informationNetwork Security. Chapter 3 Symmetric Cryptography. Symmetric Encryption. Modes of Encryption. Symmetric Block Ciphers  Modes of Encryption ECB (1)
Chair for Network Architectures and Services Department of Informatics TU München Prof. Carle Network Security Chapter 3 Symmetric Cryptography General Description Modes of ion Data ion Standard (DES)
More informationThe Elements of Cryptography
The Elements of Cryptography (March 30, 2016) Abdou Illia Spring 2016 Learning Objectives Discuss Cryptography Terminology Discuss Symmetric Key Encryption Discuss Asymmetric Key Encryption Distinguish
More informationAPNIC elearning: Cryptography Basics. Contact: esec02_v1.0
APNIC elearning: Cryptography Basics Contact: training@apnic.net esec02_v1.0 Overview Cryptography Cryptographic Algorithms Encryption SymmetricKey Algorithm Block and Stream Cipher Asymmetric Key Algorithm
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 informationCRYPTOGRAPHIC PRIMITIVES AN INTRODUCTION TO THE THEORY AND PRACTICE BEHIND MODERN CRYPTOGRAPHY
CRYPTOGRAPHIC PRIMITIVES AN INTRODUCTION TO THE THEORY AND PRACTICE BEHIND MODERN CRYPTOGRAPHY Robert Sosinski Founder & Engineering Fellow Known as "America's Cryptologic Wing", is the only Air Force
More informationNETWORK ADMINISTRATION AND SECURITY
NETWORK ADMINISTRATION AND SECURITY Unit I (NAS) (W 10) Q. 1) What is Security Attack? Explain general categories of attack with examples. 7 Q. 2) List and define the five security services. 5 Q. 3) Define
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 oneround Feistel cipher
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 informationNetwork Security. Abusayeed Saifullah. CS 5600 Computer Networks. These slides are adapted from Kurose and Ross 81
Network Security Abusayeed Saifullah CS 5600 Computer Networks These slides are adapted from Kurose and Ross 81 Goals v understand principles of network security: cryptography and its many uses beyond
More informationEvaluation of the RC4 Algorithm for Data Encryption
Evaluation of the RC4 Algorithm for Data Encryption Allam Mousa (1) and Ahmad Hamad (2) (1) Electrical Engineering Department AnNajah University, Nablus, Palestine (2) Systems Engineer PalTel Company,
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. 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 informationMathematical Model Based Total Security System with Qualitative and Quantitative Data of Human
Int Jr of Mathematics Sciences & Applications Vol3, No1, JanuaryJune 2013 Copyright Mind Reader Publications ISSN No: 22309888 wwwjournalshubcom Mathematical Model Based Total Security System with Qualitative
More informationCIS 5371 Cryptography. 8. Encryption 
CIS 5371 Cryptography p y 8. Encryption  Asymmetric Techniques Textbook encryption algorithms In this chapter, security (confidentiality) is considered in the following sense: Allornothing secrecy.
More informationOverview of PublicKey Cryptography
CS 361S Overview of PublicKey Cryptography Vitaly Shmatikov slide 1 Reading Assignment Kaufman 6.16 slide 2 PublicKey Cryptography public key public key? private key Alice Bob Given: Everybody knows
More informationPublic Key (asymmetric) Cryptography
PublicKey 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 informationFirst Semester Examinations 2011/12 INTERNET PRINCIPLES
PAPER CODE NO. EXAMINER : Martin Gairing COMP211 DEPARTMENT : Computer Science Tel. No. 0151 795 4264 First Semester Examinations 2011/12 INTERNET PRINCIPLES TIME ALLOWED : Two Hours INSTRUCTIONS TO CANDIDATES
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 informationChapter 17. TransportLevel Security
Chapter 17 TransportLevel Security Web Security Considerations The World Wide Web is fundamentally a client/server application running over the Internet and TCP/IP intranets The following characteristics
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 informationPublic Key Cryptography. Basic Public Key Cryptography
Public Key Cryptography EJ Jung Basic Public Key Cryptography public key public key? private key Alice Bob Given: Everybody knows Bob s public key  How is this achieved in practice? Only Bob knows the
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 informationComputer Security: Principles and Practice
Computer Security: Principles and Practice Chapter 20 PublicKey Cryptography and Message Authentication First Edition by William Stallings and Lawrie Brown Lecture slides by Lawrie Brown PublicKey Cryptography
More informationIntroduction to Cryptography
Introduction to Cryptography Part 2: publickey cryptography JeanSébastien Coron January 2007 Publickey cryptography Invented by Diffie and Hellman in 1976. Revolutionized the field. Each user now has
More informationSecurity and Authentication Primer
Security and Authentication Primer Manfred Jantscher and Peter H. Cole AutoID Labs White Paper WPHARDWARE025 Mr. Manfred Jantscher Visiting Master Student, School of Electrical and Electronics Engineering,
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 email transport
More informationSeChat: An AES Encrypted Chat
Name: Luis Miguel Cortés Peña GTID: 901 67 6476 GTG: gtg683t SeChat: An AES Encrypted Chat Abstract With the advancement in computer technology, it is now possible to break DES 56 bit key in a meaningful
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 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 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 informationCS 393 Network Security. Nasir Memon Polytechnic University Module 11 Secure Email
CS 393 Network Security Nasir Memon Polytechnic University Module 11 Secure Email Course Logistics HW 5 due Thursday Graded exams returned and discussed. Read Chapter 5 of text 4/2/02 Module 11  Secure
More informationSAMPLE EXAM QUESTIONS MODULE EE5552 NETWORK SECURITY AND ENCRYPTION ECE, SCHOOL OF ENGINEERING AND DESIGN BRUNEL UNIVERSITY UXBRIDGE MIDDLESEX, UK
SAMPLE EXAM QUESTIONS MODULE EE5552 NETWORK SECURITY AND ENCRYPTION September 2010 (reviewed September 2014) ECE, SCHOOL OF ENGINEERING AND DESIGN BRUNEL UNIVERSITY UXBRIDGE MIDDLESEX, UK NETWORK SECURITY
More informationSecure Sockets Layer (SSL ) / Transport Layer Security (TLS) Network Security Products S31213
Secure Sockets Layer (SSL ) / Transport Layer Security (TLS) Network Security Products S31213 UNCLASSIFIED Example http ://www. greatstuf f. com Wants credit card number ^ Look at lock on browser Use https
More informationEnhancing Advanced Encryption Standard SBox Generation Based on Round Key
Enhancing Advanced Encryption Standard SBox Generation Based on Round Key Julia Juremi Ramlan Mahmod Salasiah Sulaiman Jazrin Ramli Faculty of Computer Science and Information Technology, Universiti Putra
More informationEDA385 Embedded Systems Design. Advanced Course
EDA385 Embedded Systems Design. Advanced Course Encryption for Embedded Systems Supervised by Flavius Gruian Submitted by Ahmed Mohammed Youssef (aso10ayo) Mohammed Shaaban Ibraheem Ali (aso10mib) Orges
More informationOverview of Symmetric Encryption
CS 361S Overview of Symmetric Encryption Vitaly Shmatikov Reading Assignment Read Kaufman 2.14 and 4.2 slide 2 Basic Problem   ? Given: both parties already know the same secret Goal: send
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 information3.2: Transport Layer: SSL/TLS Secure Socket Layer (SSL) Transport Layer Security (TLS) Protocol
Chapter 2: Security Techniques Background Chapter 3: Security on Network and Transport Layer Network Layer: IPSec Transport Layer: SSL/TLS Chapter 4: Security on the Application Layer Chapter 5: Security
More informationApplication Layer (1)
Application Layer (1) Functionality: providing applications (email, www, USENET etc) providing support protocols to allow the real applications to function properly security comprising a large number
More informationLukasz Pater CMMS Administrator and Developer
Lukasz Pater CMMS Administrator and Developer EDMS 1373428 Agenda Introduction Why do we need asymmetric ciphers? Oneway functions RSA Cipher Message Integrity Examples Secure Socket Layer Single Sign
More informationCryptographic Hash Functions Message Authentication Digital Signatures
Cryptographic Hash Functions Message Authentication Digital Signatures Abstract We will discuss Cryptographic hash functions Message authentication codes HMAC and CBCMAC Digital signatures 2 Encryption/Decryption
More informationChapter 10 AsymmetricKey Cryptography
Chapter 10 AsymmetricKey Cryptography Copyright The McGrawHill Companies, Inc. Permission required for reproduction or display. 10.1 Chapter 10 Objectives Present asymmetrickey cryptography. Distinguish
More informationPractice Questions. CS161 Computer Security, Fall 2008
Practice Questions CS161 Computer Security, Fall 2008 Name Email address Score % / 100 % Please do not forget to fill up your name, email in the box in the midterm exam you can skip this here. These practice
More informationToday ENCRYPTION. Cryptography example. Basic principles of cryptography
Today ENCRYPTION The last class described a number of problems in ensuring your security and privacy when using a computer online. This lecture discusses one of the main technological solutions. The use
More informationNetwork Security. HIT Shimrit TzurDavid
Network Security HIT Shimrit TzurDavid 1 Goals: 2 Network Security Understand principles of network security: cryptography and its many uses beyond confidentiality authentication message integrity key
More informationThe Misuse of RC4 in Microsoft Word and Excel
The Misuse of RC4 in Microsoft Word and Excel Hongjun Wu Institute for Infocomm Research, Singapore hongjun@i2r.astar.edu.sg Abstract. In this report, we point out a serious security flaw in Microsoft
More informationData Encryption A B C D E F G H I J K L M N O P Q R S T U V W X Y Z. we would encrypt the string IDESOFMARCH as follows:
Data Encryption Encryption refers to the coding of information in order to keep it secret. Encryption is accomplished by transforming the string of characters comprising the information to produce a new
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 informationDeveloping and Investigation of a New Technique Combining Message Authentication and Encryption
Developing and Investigation of a New Technique Combining Message Authentication and Encryption Eyas ElQawasmeh and Saleem Masadeh Computer Science Dept. Jordan University for Science and Technology P.O.
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 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 informationNetwork Security. Security Attacks. Normal flow: Interruption: 孫 宏 民 hmsun@cs.nthu.edu.tw Phone: 035742968 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: 035742968 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 informationSavitribai Phule Pune University
Savitribai Phule Pune University Centre for Information and Network Security Course: Introduction to Cyber Security / Information Security Module : Prerequisites in Information and Network Security Chapter
More informationLecture 6  Cryptography
Lecture 6  Cryptography CSE497b  Spring 2007 Introduction Computer and Network Security Professor Jaeger www.cse.psu.edu/~tjaeger/cse497bs07 Question 2 Setup: Assume you and I don t know anything about
More informationSecret File Sharing Techniques using AES algorithm. C. Navya Latha 200201066 Garima Agarwal 200305032 Anila Kumar GVN 200305002
Secret File Sharing Techniques using AES algorithm C. Navya Latha 200201066 Garima Agarwal 200305032 Anila Kumar GVN 200305002 1. Feature Overview The Advanced Encryption Standard (AES) feature adds support
More information, ) I Transport Layer Security
Secure Sockets Layer (SSL, ) I Transport Layer Security _ + (TLS) Network Security Products S31213 UNCLASSIFIED Location of SSL L Protocols TCP Ethernet IP SSL Header Encrypted SSL data= HTTP " Independent
More informationVoIP Security. Seminar: Cryptography and Security. 07.06.2006 Michael Muncan
VoIP Security Seminar: Cryptography and Security Michael Muncan Overview Introduction Secure SIP/RTP Zfone Skype Conclusion 1 Introduction (1) Internet changed to a mass media in the middle of the 1990s
More informationEXAM questions for the course TTM4135  Information Security June 2010. Part 1
EXAM questions for the course TTM4135  Information Security June 2010 Part 1 This part consists of 6 questions all from one common topic. The number of maximal points for every correctly answered question
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 informationCS Computer and Network Security: Applied Cryptography
CS 5410  Computer and Network Security: Applied Cryptography Professor Patrick Traynor Spring 2016 Reminders Project Ideas are due on Tuesday. Where are we with these? Assignment #2 is posted. Let s get
More informationCryptography and Network Security, PART IV: Reviews, Patches, and11.2012 Theory 1 / 53
Cryptography and Network Security, PART IV: Reviews, Patches, and Theory Timo Karvi 11.2012 Cryptography and Network Security, PART IV: Reviews, Patches, and11.2012 Theory 1 / 53 Key Lengths I The old
More informationlundi 1 octobre 2012 In a set of N elements, by picking at random N elements, we have with high probability a collision two elements are equal
Symmetric Crypto PierreAlain Fouque Birthday Paradox In a set of N elements, by picking at random N elements, we have with high probability a collision two elements are equal N=365, about 23 people are
More informationDigital Signatures. Murat Kantarcioglu. Based on Prof. Li s Slides. Digital Signatures: The Problem
Digital Signatures Murat Kantarcioglu Based on Prof. Li s Slides Digital Signatures: The Problem Consider the reallife example where a person pays by credit card and signs a bill; the seller verifies
More informationECE 428 Network Security
ECE 428 Network Security 1 Learning objectives Security requirements and tools Symmetrickey (secret key) cryptography Substitution, transposition, and product ciphers (DES) Public key cryptography: RSA
More informationCPS 590.5 Computer Security Lecture 9: Introduction to Network Security. Xiaowei Yang xwy@cs.duke.edu
CPS 590.5 Computer Security Lecture 9: Introduction to Network Security Xiaowei Yang xwy@cs.duke.edu Previous lectures Worm Fast worm design Today Network security Cryptography building blocks Existing
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 informationCS 161 Computer Security
Song Spring 2015 CS 161 Computer Security Discussion 11 April 7 & April 8, 2015 Question 1 RSA (10 min) (a) Describe how to find a pair of public key and private key for RSA encryption system. Find two
More information