Math 478: The Mathematics of Public Key Cryptography

Math 478

Topics in Number Theory:  The Mathematics of Public Key Cryptography

Winter 2017-2018

Instructor: Joshua Holden
Office: G207
Office Phone: 877-8320
E-mail: holden@rose-hulman.edu
Web Page: http://www.rose-hulman.edu/~holden


Description

Maybe this looks familiar:  (If it doesn’t, that’s okay too!)

                                                                                                              

Alice                                                                            Eve                                                                   Bob

makes encryption key E
makes decryption key D
posts encryption key E
“Now Alice can send me a message!”

“I want to send a message to Bob.”
looks up Bob’s encryption key E

“Hi, Bob, this is Alice.”
↓E
JDAOEBCMXFMZNCTKKAKDNZC

JDAOEBCMXFMZNCTKKAKDNZC→
looks up E
“I don’t know D.”
“How do I invert the function?”

JDAOEBCMXFMZNCTKKAKDNZC
↓ D
“Hi, Bob, this is Alice.”

 

But do you know this one?

                                                                                                              

Alice                                                                            Eve                                                                   Bob

“I want to send a message to Bob, but all I know is his email.”

“Hi, Bob, this is Alice.”
↓bob@bobsemail.com
JDAOEBCMXFMZNCTKKAKDNZC

JDAOEBCMXFMZNCTKKAKDNZC→
looks up bob@bobsemail.com
“How do I invert the function?”

“Oh, look, it’s a message.”
bob@bobsemail.com↓
makes decryption key D

JDAOEBCMXFMZNCTKKAKDNZC
↓ D
“Hi, Bob, this is Alice.”

How can Alice send Bob a secret message before Bob even knows he needs a secret key???

We are going to be using facts about integers to do some cool things in cryptography, like Identity-Based Encryption. You don’t have to know anything about cryptography to start, but if you do I think you will still learn something new!

Requirements

The prerequisite for this class is DISCO I (Math 275) or Number Theory (Math 378).   (Banner says Math 375 but I will waive that if you have had Math 275.)  If you have had some other experience with number theory or cryptography, come see me and we’ll talk.

Class Schedule Information from Banner