We think you have liked this presentation. If you wish to download it, please recommend it to your friends in any social system. Share buttons are a little bit lower. Thank you!
Presentation is loading. Please wait.
Published byChloe Lopez
Modified over 5 years ago
Symmetric Message Authentication Codes Prof. Ravi Sandhu
2 © Ravi Sandhu MESSAGE AUTHENTICATION CODES MAC Algorithm M Verification Algorithm V Plain- text Yes/No Plaintext + MAC INSECURE CHANNEL K A A B B K MAC = MD of plaintext + K
3 © Ravi Sandhu CURRENT GENERATION MAC ALGORITHMS HMAC-MD5, HMAC-SHA IETF standard general technique for constructing a MAC from a message digest algorithm Older MACs are based on secret key encryption algorithms (notably DES) and are still in use DES based MACs are 64 bit and not considered strong anymore
4 © Ravi Sandhu HMAC HMAC computation HMAC K (M) = h(K opad || h(K ipad || M) ) h is any message digest function M message K secret key opad, ipad: fixed outer and inner padding HMAC-MD5, HMAC-SHA
ISA 662 SSL Prof. Ravi Sandhu. 2 © Ravi Sandhu SECURE SOCKETS LAYER (SSL) layered on top of TCP SSL versions 1.0, 2.0, 3.0, 3.1 Netscape protocol later.
Symmetric Encryption Prof. Ravi Sandhu.
Asymmetric Digital Signatures And Key Exchange Prof. Ravi Sandhu.
Asymmetric Encryption Prof. Ravi Sandhu. 2 © Ravi Sandhu PUBLIC KEY ENCRYPTION Encryption Algorithm E Decryption Algorithm D Plain- text Plain- text Ciphertext.
PKI Introduction Ravi Sandhu 2 © Ravi Sandhu 2002 CRYPTOGRAPHIC TECHNOLOGY PROS AND CONS SECRET KEY SYMMETRIC KEY Faster Not scalable No digital signatures.
Hashes and Message Digests
Lecture 5: Cryptographic Hashes
Lecture 7 Overview. Advanced Encryption Standard 10, 12, 14 rounds for 128, 192, 256 bit keys – Regular Rounds (9, 11, 13) – Final Round is different.
MAC Raushan. DES simple fiestel network 3131 PlainText Blocks 2*4=8bits 31 f f =0011 xor 0011=0000 = 0 f(r,k)=(2*r+k^2)%8 f(1,5)=(2*1+5^2)%8=3 xor 3 3.
CS 483 – SD SECTION BY DR. DANIYAL ALGHAZZAWI (3) Information Security.
ECE454/CS594 Computer and Network Security Dr. Jinyuan (Stella) Sun Dept. of Electrical Engineering and Computer Science University of Tennessee Fall 2011.
Socket Layer Security. In this Presentation: need for web security SSL/TLS transport layer security protocols HTTPS secure shell (SSH)
An Introduction to Secure Sockets Layer (SSL). Overview Types of encryption SSL History Design Goals Protocol Problems Competing Technologies.
Transport Layer Security (TLS) Protocol Introduction to networks and communications(CS555) Prof : Dr Kurt maly Student:Abhinav y.
SSL Prof. Ravi Sandhu. 2 © Ravi Sandhu CONTEXT Mid to late 90’s SSL 1.0 never released SSL 2.0 flawed SSL 3.0 complete redesign TLS from Netscape.
Session 5 Hash functions and digital signatures. Contents Hash functions – Definition – Requirements – Construction – Security – Applications 2/44.
1 Chapter 5 Hashes and Message Digests Instructor: 孫宏民 Room: EECS 6402, Tel: , Fax :
HASH ALGORITHMS - Chapter 12
Dr Alejandra Flores-Mosri Message Authentication Internet Management & Security 06 Learning outcomes At the end of this session, you should be able to:
BY MUKTADIUR RAHMAN MAY 06, 2010 INTERODUCTION TO CRYPTOGRAPHY.
© 2019 SlidePlayer.com Inc. All rights reserved.