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 - ["The Functionality of zk-SNARK"](http://qed-it.com/2017/07/challenge-one-the-functionality-of-zk-snark/) challenge set in ["The Hunting of the SNARK"](http://qed-it.com/2017/07/the-hunting-of-the-snark/).
 - ["Probabilistic Proof Systems"](http://people.cs.georgetown.edu/jthaler/COSC544.html) course notes
 - Vitalik Buterin's introduction to SNARKs, part [1](https://medium.com/@VitalikButerin/quadratic-arithmetic-programs-from-zero-to-hero-f6d558cea649), [2](https://medium.com/@VitalikButerin/exploring-elliptic-curve-pairings-c73c1864e627), and [3](https://medium.com/@VitalikButerin/zk-snarks-under-the-hood-b33151a013f6); and STARKs, part [1](https://vitalik.ca/general/2017/11/09/starks_part_1.html), [2](https://vitalik.ca/general/2017/11/22/starks_part_2.html), and [3](https://vitalik.ca/general/2018/07/21/starks_part_3.html).
+- [How and Why a zk-SNARK Work](https://arxiv.org/abs/1906.07221)
 
 ## History of Zero-knowledge proofs