s-intro_s

s-intro_s - Course Information CSE 107 — Introduction to...

Info iconThis preview shows pages 1–15. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Course Information CSE 107 — Introduction to Modern Cryptography Instructor: Mihir Bellare Website: http://www-cse.ucsd.edu/users/mihir/cse107 1 / 56 Cryptography usage Did you use any cryptography • today? • over the last week? • over the Christmas break? 2 / 56 Cryptography usage • https invokes the Secure Socket Layer (SSL) communication security protocol to securely transmit your credit card number to the server • SSL uses cryptography 3 / 56 Cryptography usage Other uses of cryptography • ATM machines • On-line banking • Remote login and file transfer using SSH 4 / 56 What is cryptography about? Adversary: clever person with powerful computer Goals: • Data privacy • Data integrity and authenticity 5 / 56 Privacy The goal is to ensure that the adversary does not see or obtain the data (message) M . Example : M could be a credit card number being sent by shopper Alice to server Bob and we want to ensure attackers don’t learn it. 6 / 56 Integrity and authenticity The goal is to ensure that • M really originates with Alice and not someone else • M has not been modified in transit 7 / 56 Integrity and authenticity example Alice Bob (Bank) Alice Pay $100 to Charlie a45 Adversary Eve might • Modify “Charlie” to “Eve” • Modify “$100” to “$1000” Integrity prevents such attacks. 8 / 56 Medical databases Doctor Reads F A Modifies F A to F ′ A Get Alice a45 F A a27 Put: Alice, F ′ A a45 Database Alice F A Bob F B Alice F ′ A Bob F B • Privacy: F A , F ′ A contain confidential information and we want to ensure the adversary does not obtain them • Integrity and authenticity: Need to ensure – doctor is authorized to get Alice’s file – F A , F ′ A are not modified in transit – F A is really sent by database – F ′ A is really sent by (authorized) doctor 9 / 56 What is cryptography about? Adversary: clever person with powerful computer Goals: • Data privacy • Data integrity and authenticity 10 / 56 Ideal World Cryptonium pipe: Cannot see inside or alter content. All our goals would be achieved! But cryptonium is only available on planet Crypton and is in short supply. 11 / 56 Cryptographic schemes E : encryption algorithm D : decryption algorithm K e : encryption key K d : decryption key Algorithms: standardized, implemented, public! 12 / 56 Cryptographic schemes E : encryption algorithm D : decryption algorithm K e : encryption key K d : decryption key Settings: • public-key (assymmetric): K e public, K d secret • private-key (symmetric): K e = K d secret 13 / 56 Cryptographic schemes E : encryption algorithm D : decryption algorithm K e : encryption key K d : decryption key How do keys get distributed? Magic, for now!...
View Full Document

This note was uploaded on 10/10/2010 for the course CSE CSE107 taught by Professor Bellare during the Spring '10 term at UCSD.

Page1 / 57

s-intro_s - Course Information CSE 107 — Introduction to...

This preview shows document pages 1 - 15. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online