{{위키데이터 속성 추적}}
'''작업 증명 시스템'''({{lang|en|proof-of-work (PoW) system}} 또는 protocol, function)은 서비스 요청자로부터 일부 작업을 요구함으로써(일반적으로 컴퓨터에 의한 처리 시간을 의미) [[서비스 거부 공격|서비스 거부]](DoS) 공격과 기타 서비스 악용(예: 네트워크 상의 [[스팸 광고|스팸]])을 단념하게 만들기 위한 경제적인 수단이다. 이 개념은 1993년의 어느 한 잡지 기사에서 제시된 바에 따르면 Cynthia Dwork와 Moni Naor에 의해 발명되었다.{{r|"DwoNao1992"}} "작업 증명"(Proof of Work, POW)이라는 용어는 1999년 논문에서 Markus Jakobsson와 Ari Juels에 의해 처음 만들어져 공식화되었다.<ref name="JaJue1999">{{저널 인용
 | first1 = Markus | last1 =  Jakobsson | first2 = Ari | last2 = Juels
 | url = http://www.emc.com/emc-plus/rsa-labs/staff-associates/proofs-of-work-protocols.htm
 | title = Proofs of Work and Bread Pudding Protocols
 | journal = Communications and Multimedia Security | pages = 258–272 | publisher = Kluwer Academic Publishers | year =1999
}}</ref> 통화에 가치를 제공하기 위해 사용된 작업 증명 시스템의 초기 예는 [[솔로몬 제도]]의 [[조가비 화폐]]이다.

== 작업 증명 기능 목록 ==
아래에는 현재 알려진 작업 증명 함수의 목록이다:
* [[제곱잉여|정수제곱근법]] 큰 소수<ref name="DwoNao1992">{{저널 인용
 | first1 = Cynthia | last1 = Dwork | author1-link = Cynthia Dwork | first2 = Moni | last2 = Naor | author2-link = Moni Naor
 | title = Pricing via Processing, Or, Combatting Junk Mail, Advances in Cryptology
 | journal = CRYPTO’92: Lecture Notes in Computer Science No. 740 | publisher =  Springer | year = 1993 | pages = 139–147
 | url = http://www.wisdom.weizmann.ac.il/~naor/PAPERS/pvp.ps
}}</ref>
* 약한 [[Fiat–Shamir heuristic|Fiat–Shamir]] 서명<ref name="DwoNao1992"/>
* Ong–Schnorr–Shamir 서명 (broken by Pollard)<ref name="DwoNao1992"/>
* 부분 해시 반전(Partial hash inversion)<ref name="Ba1997">{{웹 인용
 | first = Adam | last =  Back
 | url = http://hashcash.org
 | title =  HashCash
}} Popular proof-of-work system. First announce in March 1997.</ref><ref name="GaJaMaMa1998">{{저널 인용
 | first1 = Eran | last1 = Gabber | first2 = Markus | last2 = Jakobsson | first3 = Yossi | last3 = Matias | first4 = Alain J. | last4 =Mayer
 | title = Curbing junk e-mail via secure classification | journal = Financial Cryptography | pages = 198–213 | year = 1998
}}</ref>{{r|"JaJue1999"}} 이 논문은 작업 증명(POW)의 개념을 공식화하고 재사용 가능한 작업 증명(RPOW) 시스템의 하나인 브레드 푸딩 프로토콜(bread pudding protocol)의 독립적인 개념을 도입하고 있다.<ref name="WaRei2003">{{저널 인용 | first1 = Xiao-Feng | last1 = Wang | first2 = Michael | last2 = Reiter | title = Defending against denial-of-service attacks with puzzle auctions | journal = IEEE Symposium on Security and Privacy '03 | date = May 2003 | url = http://cs.unc.edu/~reiter/papers/2003/SP.pdf | access-date = 2018-05-11 | archive-date = 2016-03-03 | archive-url = https://web.archive.org/web/20160303220133/http://cs.unc.edu/~reiter/papers/2003/SP.pdf }}</ref> ([[해시캐시]]로서)
* 해시 수열(Hash sequences)<ref name="FraMa1997">{{저널 인용
 | first1 = Matthew K. | last1 = Franklin | author1-link = Matthew K. Franklin | first2 = Dahlia | last2 = Malkhi | author2-link = Dahlia Malkhi
 | title =  Auditable metering with lightweight security
 | journal = Financial Cryptography '97 | year = 1997}} Updated version May 4, 1998.</ref>
* 퍼즐<ref name="JueBrai1999">{{저널 인용
 | first1 = Ari | last1 =  Juels | first2 = John | last2 = Brainard
 | title =  Client puzzles: A cryptographic defense against connection depletion attacks | journal =  NDSS 99 | year = 1999 }}</ref>
* [[디피-헬먼 키 교환|디피-헬먼]] 기반 퍼즐<ref name="WaJueHaFe2004">{{저널 인용
 | first1 = Brent | last1 = Waters | first2 = Ari | last2 = Juels | first3 = John A. | last3 = Halderman | first4 = Edward W. | last4 = Felten | author4-link = Edward Felten
 | title =  New client puzzle outsourcing techniques for DoS resistance
 | journal =  11th ACM Conference on Computer and Communications Security | year = 2004
}}</ref>
* Moderate<ref name="ABuMaWo2003">{{저널 인용
 | first1 = Martín | last1 =  Abadi | author1-link = Martín Abadi | first2 = Mike | last2 =  Burrows | first3 = Mark | last3 = Manasse | first4 = Ted | last4 = Wobber
 | title = Moderately hard, memory-bound functions
 | journal = ACM Trans. Inter. Tech. | volume =  5 | number = 2 | pages = 299–327 | year = 2005
}}</ref>
* Mbound<ref name="DwoGoNao2003">{{저널 인용
 | first1 = Cynthia | last1 =  Dwork | author1-link = Cynthia Dwork | first2 =  Andrew | last2 =  Goldberg | author2-link = Andrew V. Goldberg | first3 = Moni | last3 = Naor | author3-link = Moni Naor
 | title =   On memory-bound functions for fighting spam
 | journal = Advances in Cryptology: CRYPTO 2003 |  volume = 2729 |  pages= 426–444 | publisher =  Springer | year = 2003
}}</ref>
* Hokkaido<ref name="Coe2005">{{웹 인용
 | first = Fabien | last =  Coelho
 | title =  Exponential memory-bound functions for proof of work protocols
 | work =  Cryptology ePrint Archive, Report
 | url =  http://eprint.iacr.org/2005/356
}}</ref>
* Cuckoo Cycle<ref name="Tro2014">{{웹 인용
 | first = John | last = Tromp
 | title = Cuckoo Cycle; a memory bound graph-theoretic proof-of-work
 | url = https://eprint.iacr.org/2014/059.pdf
 | journal = Financial Cryptography and Data Security: BITCOIN 2015 | publisher = Springer | pages = 49–62 | year = 2015
}}</ref>
* [[해시 트리|머클 트리]] 기반<ref name="Coe2007">{{웹 인용
 | first = Fabien | last =  Coelho
 | title = An (almost) constant-effort solution-verification proof-of-work protocol based on Merkle trees
 | work =  Cryptology ePrint Archive, Report  | url = http://eprint.iacr.org/2007/433
}}</ref>
* [[Guided tour puzzle protocol]]<ref name="Abliz09">{{저널 인용
 | first1 = Mehmud | last1 =  Abliz | first2 = Taieb | last2 = Znati
 | title =  A Guided Tour Puzzle for Denial of Service Prevention
 | journal  = Proceedings of the Annual Computer Security Applications Conference (ACSAC) 2009
  | pages = 279–288 | location =  Honolulu, HI |date=December 2009
}}</ref>

== 같이 보기 ==
* [[비트코인]]
* [[암호화폐]]

== 각주 ==
{{각주}}

== 외부 링크 ==
* {{웹 인용 |url=http://rpow.net/ |제목=Finney's system |확인날짜=2018-05-11 |보존url=https://web.archive.org/web/20071222072154/http://rpow.net/ |보존날짜=2007-12-22 |url-status= }}
* [[bit gold]] [http://unenumerated.blogspot.com/2005/12/bit-gold.html Bit gold].  ''Describes a complete money system (including generation, storage, assay, and transfer) based on proof of work functions and the machine architecture problem raised by the use of these functions.''

{{비트코인}}
{{암호화폐}}

[[분류:암호학]]
[[분류:암호화폐]]