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 byAmia Hammond
Modified over 3 years ago
Asymmetric Encryption Prof. Ravi Sandhu
2 © Ravi Sandhu PUBLIC KEY ENCRYPTION Encryption Algorithm E Decryption Algorithm D Plain- text Plain- text Ciphertext INSECURE CHANNEL B's Public Key B's Private Key RELIABLE CHANNEL A A B B
3 © Ravi Sandhu PUBLIC KEY CRYPTOSYSTEM solves the key distribution problem provided there is a reliable channel for communication of public keys requires reliable dissemination of 1 public key/party scales well for large-scale systems
4 © Ravi Sandhu PUBLIC KEY ENCRYPTION confidentiality based on infeasibility of computing B's private key from B's public key key sizes are large (512 bits and above) to make this computation infeasible
5 © Ravi Sandhu SPEED OF PUBLIC KEY VERSUS SECRET KEY Public key runs at kilobits/second think modem connection Secret key runs at megabits/second and even gigabits/second think LAN or disk connection This large difference in speed is likely to remain independent of technology advances
6 © Ravi Sandhu RSA public key is (n,e) private key is d encrypt: C = M e mod n decrypt: M = C d mod n
7 © Ravi Sandhu GENERATION OF RSA KEYS choose 2 large (100 digit) prime numbers p and q compute n = p * q pick e relatively prime to (p-1)*(q-1) compute d, e*d = 1 mod (p-1)*(q-1) publish (n,e) keep d secret (and discard p, q)
8 © Ravi Sandhu PROTECTION OF RSA KEYS compute d, e*d = 1 mod (p-1)*(q-1) if factorization of n into p*q is known, this is easy to do security of RSA is no better than the difficulty of factoring n into p, q
9 © Ravi Sandhu RSA KEY SIZE key size of RSA is selected by the user casual384 bits commercial512 bits military1024 bits
Asymmetric Digital Signatures And Key Exchange Prof. Ravi Sandhu.
1 Public-Key Cryptography and Message Authentication.
Chapter 3 – Public Key Cryptography and RSA (A). Private-Key Cryptography traditional private/secret/single-key cryptography uses one key shared by both.
Encryption on the Internet Jeff Cohen. Keeping Information Secret What information do we want to be secret? –Credit card number –Social security number.
“RSA”. RSA by Rivest, Shamir & Adleman of MIT in 1977 best known & widely used public-key scheme RSA is a block cipher, plain & cipher text are.
PKI Introduction Ravi Sandhu 2 © Ravi Sandhu 2002 CRYPTOGRAPHIC TECHNOLOGY PROS AND CONS SECRET KEY SYMMETRIC KEY Faster Not scalable No digital signatures.
Introduction Requirements for RSA Ingredients for RSA RSA Algorithm RSA Example Problems on RSA.
Asymmetric encryption. Asymmetric encryption, often called "public key" encryption, allows Alice to send Bob an encrypted message without a shared secret.
WS Algorithmentheorie 03 – Randomized Algorithms (Public Key Cryptosystems) Prof. Dr. Th. Ottmann.
Public Key Model 8. Cryptography part 2.
Cryptography1 CPSC 3730 Cryptography Chapter 9 Public Key Cryptography and RSA.
24-Nov-15Security Cryptography Cryptography is the science and art of transforming messages to make them secure and immune to attacks. It involves plaintext,
Public Key Cryptography. symmetric key crypto requires sender, receiver know shared secret key Q: how to agree on key in first place (particularly if.
Symmetric Encryption Prof. Ravi Sandhu.
7. Asymmetric encryption-
Public-Key Cryptography CS110 Fall Conventional Encryption.
Darci Miyashiro Math 480 April 29, 2013
Module 3 – Cryptography Cryptography basics Ciphers Symmetric Key Algorithms Public Key Algorithms Message Digests Digital Signatures.
Chapter 9 Public Key Cryptography and RSA. Private-Key Cryptography traditional private/secret/single key cryptography uses one key shared by both sender.
Public Key Cryptography Nick Feamster CS 6262 Spring 2009.
Fall 2010/Lecture 311 CS 426 (Fall 2010) Public Key Encryption and Digital Signatures.
Computer and Network Security Rabie A. Ramadan Lecture 6.
1 Pertemuan 08 Public Key Cryptography Matakuliah: H0242 / Keamanan Jaringan Tahun: 2006 Versi: 1.
Cryptography and Network Security Third Edition by William Stallings Lecture slides by Lawrie Brown.
Dr.Saleem Al_Zoubi1 Cryptography and Network Security Third Edition by William Stallings Public Key Cryptography and RSA.
BASIC CRYPTOGRAPHIC CONCEPTS. Public Key Cryptography Uses two keys for every simplex logical communication link. Public key Private key The use.
1 CIS 5371 Cryptography 8. Asymmetric encryption-.
Private-Key Cryptography traditional private/secret/single key cryptography uses one key shared by both sender and receiver if this key is disclosed communications.
Public Key Cryptography RSA Diffie Hellman Key Management Based on slides by Dr. Lawrie Brown of the Australian Defence Force Academy, University College,
Public Key Cryptography INFSCI 1075: Network Security – Spring 2013 Amir Masoumzadeh.
Symmetric Message Authentication Codes Prof. Ravi Sandhu.
RSA ( Rivest, Shamir, Adleman) Public Key Cryptosystem
BY MUKTADIUR RAHMAN MAY 06, 2010 INTERODUCTION TO CRYPTOGRAPHY.
COMP 424 Lecture 04 Advanced Encryption Techniques (DES, AES, RSA)
CSCE 715: Network Systems Security Chin-Tser Huang University of South Carolina.
Introduction to Public Key Cryptography
IS 302: Information Security and Trust Week 4: Asymmetric Encryption
Dr. Lo’ai Tawalbeh Summer 2007 Chapter 9 – Public Key Cryptography and RSA Dr. Lo’ai Tawalbeh New York Institute of Technology (NYIT) Jordan’s Campus INCS.
CSCE 201 Introduction to Information Security Fall 2010 Data Protection.
Cryptographic Security Aveek Chakraborty CS5204 – Operating Systems1.
Chi-Cheng Lin, Winona State University CS 313 Introduction to Computer Networking & Telecommunication Network Security (A Very Brief Introduction)
CMSC 414 Computer and Network Security Lecture 6 Jonathan Katz.
Public Key Cryptography
Encryption Basics Module 7 Section 2. History of Encryption Secret - NSA National Security Agency –has powerful computers - break codes –monitors all.
Cryptography 1 Crypto Cryptography 2 Crypto Cryptology The art and science of making and breaking “secret codes” Cryptography making “secret.
Public Key Cryptosystem Introduced in 1976 by Diffie and Hellman  In PKC different keys are used for encryption and decryption 1978: First Two Implementations.
© 2017 SlidePlayer.com Inc. All rights reserved.