CompSci 461/661
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CompSci 461/661

General

Instructor: G. Andrew Stone (gastone@umass.edu): Office Hours on Tues by appointment (send a message on Piazza) or via Zoom (813 149 9032) any day most times (PM me on Piazza). My office is LGRT A246 (Lederle). You can always drop by on Tuesdays even just to chat, but an appointment ensures that I’ll be there!

Syllabus

TAs:
Joseph Majesky jmajesky@umass.edu
Jenish Bajracharya jbajracharya@umass.edu

Graders:
Tasmiya Fathima tfathima@umass.edu
Saumya Pandey saumyapandey@umass.edu

Classroom:
461: Tues 2:30PM - 3:45PM: Computer Sciences Building 140
661: Tues 4:00PM - 5:15PM: Computer Sciences Building 140 (remote students use Zoom meeting: https://umass-amherst.zoom.us/j/92771831987 code 661)

Discussion: Piazza
Assignment Submission: Gradescope Course Entry Code: 8YNPVV
Midterm: In class TBD
Final: BOTH SECTIONS: TBD
For the Midterm and final you may bring a 8.5x11" doublesided HANDWRITTEN by yourself, NOT PRINTED, cheat sheet. If it is too big I will make it smaller by ripping it! If it is not handwritten I will take it before the exam.

General Reference Materials:

Bitcoin (UTXO) blockchain Concepts
Math
Ethereum

In Class Notes and Recordings

Week N notes
Recordings

Weekly Process

Each week we’ll follow the same pattern:

  1. Skim the written materials.
  2. Watch the video, which is an overview of the written material. It does not replace them!
  3. Read through the written materials in detail.
  4. Come to class prepared for discussion with questions remaining from what you read, and ready to answer questions from your instructor. Discussion is not a repeat of the videos. It moves deeper on the video topics, and new material will be introduced! Attendance is mandatory!

Week 7: Oct 20 Midterm In class

Week 6: Oct 7-Oct13

Week 5: Sep30-Oct6 Bitcoin Networking, Eclipse Attacks, and Distributed Clock Synchronization

We are going to use short excerpts from “Distributed Systems: Principles and Paradigms” by Andrew S. Tanenbaum and Maarten Van Steen. Fortunately, the entire text is available for free! Just give any email address to the author’s web site and they’ll send you a PDF.

Please read:

  • Section 6.1: Clock Synchronization (no need to read the Berkeley algorithm or about wireless networks)
  • Section 6.2: Logical clocks

Later in the semester, we’ll use the text for another topic.

Reference

Purely optional reading for the course, but if you are interested, here is the original Lamport paper:

Week 4: (Sept 23-29) Elliptic Curve Crypto

661 only
Continue to understand the mining process: review this paper Attacks against Autofinalization and Parking.
Understand:

  • That a variety of “tweaks” can be invented to modify Satoshi’s algorithm to choose the “main chain”
  • What two proposed tweaks: “autofinalization” and “parking” actually do
  • There is no description of this consensus change, except for the source code located in this function (reading just the comments may be helpful).

Week 3: (Sep 16 - 22) Selfish Mining, Sybil Attack

Please skim the papers, watch the videos, and then read the papers carefully.

Reference

Week 2: (Sep 9-15) Cryptography Overview, Doublespend Attacks

We continue our investigation into basic blockchain architecture.

λ=zqp\lambda = \frac{zq}{p}
1−∑k=0z+1(λke−λk!)(1−(q/p)z+1−k),ifq<p1- \sum_{k=0}^{z+1} (\frac{\lambda^ke^{-\lambda}}{k!})(1-(q/p)^{z+1-k}), if q < p

Question to show you really understand the above: Why is lambda zq/p not (z+1)q/p since we stuck z+1 in other places for z?

Reference

Week 1: Introduction

These are the materials for our first week.

Reference