ZeroCash 프로토콜과 이더이움이 만나게 되었습니다.
제로캐시 프로토콜은 수년전 제로코인으로 부터 시작되어 코인의 익명화 솔루션들중 가장 고도의 수준으로 평가되어 왔습니다. 하지만 개발진들이 대학강단중심이어서 그런지 실제 활용가능한 솔루션을 선보이는데 시간이 많이 걸렸습니다.
http://zerocash-project.org/how_zerocash_works
지난달 코넬대에서 열린 이더리움 부트캠프에서 제로캐시 개발자 한명이 참여했는데, 이더리움 팀과 같이 제로캐시를 이더리움 컨트랙으로 구현해보고자 시도하고 있습니다.
https://news.bitcoin.com/zcash-baby-zoe-ether-anonymous/
https://github.com/zcash/babyzoe
제로캐시가 이루고자 하는 바는 블럭체인상의 트랜잭션의 송금인을 추적이 완전히 불가능하게 막고자 하는 것입니다.
이런 익명화가 한 때 큰 트렌드가 되기는 했었는데, 여러가지 단점들이 있었습니다.
제로캐시의 주요내용은 zk-SNARK 이고, 그것은 "zero-knowledge proof of knowledge" (영지식 증명) 을 구현한 알고리듬입니다.
이것이 크립토 코인에서 가지는 역할은 단순한 익명화솔루션보다는 더 큰 것인 것 같습니다.
2015년 10월에 비탈릭이 zk-SNARK 인테그레이션을 이더리움 프로토콜의 제1과제로 삼았습니다.
블럭체인기술의 장점이자 단점이 블럭체인의 내용을 누구나 다 들여다 볼 수 있다는 것인데, 꼭 불법적인 거래가 아니라 하더라도 프라이버시를 보호해야는 컨트랙트도 얼마든지 있습니다. 내용은 볼 수가 없는데, 그 내용이 참인지 아닌지는 확인할 수 있어야 한다는 거이죠.
영지식증명에 대한 간단한 소개는 다음글을 참조하세요.
https://ko.wikipedia.org/wiki/영지식_증명
이더리움과 관련한 개념적인 아이디어의 주요내용은 HAWK 이름으로 소개되기도 했습니다.
https://www.weusecoins.com/assets/pdf/library/Hawk%20-%20The%20Blockchain%20Model%20of%20Cryptography%20and%20Privacy-Preserving%20Smart%20Contracts.pdf
다음은 비탈릭이 설정했던 이더리움 프로토콜의 4가지 주요 연구영역들입니다.
https://blog.ethereum.org/2015/10/18/vitaliks-research-and-ecosystem-update/
기록보관상 원문을 그냥 발췌해둡니다.
Research and Protocol Development
We have identified four key areas of research regarding the underlying protocol that we feel represent the key milestones standing in the way between Ethereum as it currently exists and crypto-utopia:
zk-SNARK integration: integrating, whether through a new opcode or ideally by leveraging the EVM’s existing 256-bit modular arithmetic, the ability for Ethereum contracts to verify succinct zero-knowledge proofs. Given that the verification keys can be generated entirely off-chain, this is somewhat easier than it looks, though once implemented quite a bit of infrastructural work will be needed to make it extremely useful. An initial goal will be to use it to implement ultra-private coin mixing as well as a privacy-preserving reputation (“here’s a proof showing that I have a score of over 250 according to your reputation scoring metric and using this set of data published to the blockchain, so you should trust me, but I won’t reveal which of the parties that you should trust I am”) and two-party financial contracts, and the longer-term goal will be an implementation of Hawk on Ethereum; at and outside the above-mentioned conferences, we have had some productive chats with some of the developers of these technologies on how to move forward on accomplishing this.
Casper: Ethereum’s proof of stake algorithm now under development by Vlad Zamfir with help from Lucius Greg Meredith, myself and several others. The key components include by-block instead of by-chain consensus and the concept of “economic consensus by bet” as a way of approaching de-facto finality with exponential speed rather than linear speed as is the case with proof of work. The goal is to combine a block time reduction (my personal opinion is that 4 seconds will likely prove to be an good balance between safety and resource overconsumption and centralization risk; Vlad is as usual more aggressive), finality and much lower energy consumption (and 10-100x lower price-of-anarchy generally). Currently, Vlad and Greg are working on formally describing and implementing the non-economic part of the algorithm to mathematically prove convergence properties, and the second step will be optimizing the economics.
Scalability: using a combination of sharding schemes, random sampling, heavy use of Merkle proofs and asynchronous calling in order to increase the potential transaction throughput from ~10-20 transactions per second to over 100000 (or, if super-quadratic versions are used, a theoretically unlimited number). The basic concepts behind scaling have been set in stone for over six months, and our research team is highly confident that the general approach is valid; what remains is the details of exactly how to make optimal tradeoffs that preserve as much of Ethereum 1.0’s functionality as possible in a scalable context. A key design goal is to make sure the Ethereum 2.0 remains a superset of Ethereum 1.0; for example, synchronous calls should still be possible within a single shard, though cross-shard calls may require asynchrony. I plan on updating my scalability paper to make it more focused, readable and updated with the latest ideas over the next month or so, though in general scalability research is on the back-burner until Casper is solidified.
EVM upgrades: Martin Becze has taken the lead on exploring WebAssembly as a candidate for an upgraded Ethereum virtual machine. WebAssembly shares many properties with the EVM: the need to run untrusted code, the need for code to be very small, and the need to have multiple compatible implementations, though it lacks gas counting. WebAssembly can be used to create a just-in-time compiler for the EVM, drastically speeding up the ethereum js implementation, and it can also potentially be used as a virtual machine option itself by adding a transformation step that adds a gas subtracting instruction to code before every jump operation. Environment opcodes like BLOCKHASH, SSTORE, etc can be abstracted away by turning them into an ABI over a generic foreign function interface (eg. SSTORE(k, v) becomes FFI(0x55 ++ k ++ v) where 0x55; would be the marker representing SSTORE).
Aside from this, research questions remain on middleware “on top of” Ethereum, including on-chain services, decentralized governance, identity and reputation, random number generation, formal verification for Solidity (we have found a talented team in London that is excited about starting to explore the subject) and prediction market implementations, as well as on projects that may live “alongside” Ethereum (eg. Whisper), though the foundation is leaving it to the community to do much of this extra work as we have deliberately undertaken a strategy of focusing on the core (and doing so in a very lightweight fashion).
저도 2014년 잭팟코인 시절부터 제로캐시 개념을 도입해야 한다고 주장했었더랬습니다.
http://www.ddengle.com/board_free/880026#comment_880052
어제 재밌게 본 코인 중 하나가 vtorrent 코인이었는데...
오늘보니 비트코인다크도 있고.. piratebay coin도 있네요.. 최근 운영자가 걸리면서 이슈화 되는 듯..