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Quentin Massys. The Tax Collectors, ca. 1500

This is Part I of a series of articles taking a deeper look into the internals of the privacy protocols CoinJoin(Bitcoin), Monero, ZCash, and Mimblewimble. The goal is to give a conceptual and a bit more detailed explanation of how money transfers stored in a public ledger can be made anonymous yet verifiable by any interesting party — two seemingly contradicting requirements. This part explores CoinJoin — a privacy protocol that uses only plain vanilla Bitcoin transactions.

TL;DR

  • Bitcoin transactions transfer the right to spend a UTXO
  • Deanonymizing a few bitcoin addresses can lead to severe privacy leak since the majority of transactions can be traced…


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The much hyped concepts of Proof-Of-Work, Proof-of-Stake and Directed Acyclic Graphs are often mistakenly advertised as “consensus protocols”. Neither of them are, but rather address the key challenges of a robust blockchain design: Sybil resistance and asynchronicity.

Preface

Despite a sheer amount of buzz around blockchain, it seems that even very basic ideas are constantly getting confused even by seemingly reputable sources. Here is a recent example, pointed out by Emin Gün Sirer:

In fact, his #microlecture, delivered earlier in a smashing tweeter-storm served as the main source of inspiration.

I decided to write a more detailed note, explaining not only what is actually PoW, PoS and DAGs, but also why we need these devices in order to build a secure blockchain. And yes, they are not consensus protocols.

Here I present a short excerpt, the full article is available on GitHub. The full version contains many details I omitted in the Medium article, as well as an extensive list of references for further in-depth diving. …


Cовременный AI все еще совсем не понимает смысла того, что читает. Что такое ”смысл” понять сложно, но меня кроме этого давно занимает вопрос: ”а что собственно значит ”понимать”? (что такое ”понять” понятно — это значит простить). Кажется, что если крепко думать, то так же быстро, как и с вопросом о смысле, приходишь к Витгенштайну, позитивизму, а в конце концов в философский цугцванг. Поэтому надо отталкиваться от каких-то базовых примеров.

Как проверить, что школьник выучил таблицу умножения? Ну, проверить все 81 клеточки в таблице на обратной стороне тетради. Ок, выучить — это одно, понять — другое. Так, навык сложения произвольно больших чисел — это и есть на повседневном уровне понимание операции сложения. …

About

Dmitrii Zhelezov

Post-doc at the Renyi Institute of Mathematics, Crypto researcher

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