Instructor: Rafael Pass
Time: W
4.45-7.15
Place: Gates 405 (Ithaca), Touchdown (NYC)
Course Web page: http://www.cs.cornell.edu/courses/cs6830/2016sp/
Office
Hours: by appointment.
Course
Admin: Devaneke Crumpler
<dec89@cornell.edu>
The
modern study of cryptography investigates techniques for facilitating interactions
between distrustful entities. In our connected society, such techniques have
become indispensable---enabling, for instance, automated teller machines,
secure wireless networks, internet banking, satellite
radio/television and more.
In this
course we introduce some of the fundamental concepts of this study. Emphasis
will be placed on the foundations of cryptography and in particular on precise
definitions and proof techniques.
Topics
include: one-way functions, encryption, signatures, pseudo-random number
generation, zero-knowledge and basic protocols.
Note:
This will be a theory course. You will be expected to read and write formal
definitions and mathematical proofs. This is not a course in security: you will
not learn how to secure your system. Cryptography is only one (important) part
of security. We will not study cryptographic acronyms or all cryptographic
protocols in use today. Rather we focus on some of the fundamental design
paradigms and on notions that will allow you to critically evaluate
cryptographic protocols.
General ease with algorithms and elementary probability theory, maturity with mathematical proofs (to be able to read and write mathematical proofs)
We are using the course management system, CMS. Please login to http://cms.csuglab.cornell.edu/ and check whether you are registered. There will be a list of courses you are registered for, and CS 6830 should be one of them. If not, please send your full name and Cornell netid to the Devaneke so she can register you. You can check your grades and submit homework in CMS.
There
will be roughly 4-5 homeworks. The grade will be based
on homework assignments and class participation.
You are free to collaborate with other students on the homework, but you must turn in your own individually written solution and you must specify the names of your collaborators. Additionally, you may make use of published material, provided that you acknowledge all sources used. Note that it is a violation of this policy to submit a problem solution that you are unable to explain orally to me. Typed problem sets are strongly preferred.
Homework 1 is due on Feb 3.
G-writer ciphertext are found here: zip
You will need the following notation and preliminaries.
Lecture
notes covering a large fraction of the course can be found here.
(Background
material on discrete math from CS 2800 can be found here.)
There
is no required textbook for the course. However, most of the topics we will
cover can be found in the following excellent reference.
Hard-core
bits. Constructions of a PRGs and PRFs.
Zero
knowledge-based definitions of encryption. Equivalence with indistinguishability-based definitions.
Constant-round ZK.
1.
Computing on Secret Inputs:
2.
Composability:
1. Composability of Encryption schemes.
Chosen challenge-text, Chosen plain-text, Chosen cipher-text 1 and 2 (CCA1, CCA2).
Malleability.
2. Composability of Zero-Knowledge proofs.
3. Program Obfuscation
1. Impossibility of Virtual Black-box Obfuscation
2. Indistinguishability Obfuscation and Applications
4. Bitcoin and Proof-of-Work Based Ledgers
1. Proofs of Work
2. The Blockchain protocol