Proof-of-work sidechains

Aggelos Kiayias, Dionysis Zindros*

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract / Description of output

During the last decade, the blockchain space has exploded with a plethora of new cryptocurrencies, covering a wide array of different features, performance and security characteristics. Nevertheless, each of these coins functions in a stand-alone manner, independently. Sidechains have been envisioned as a mechanism to allow blockchains to communicate with one another and, among other applications, allow the transfer of value from one chain to another, but so far there have been no decentralized constructions. In this paper, we put forth the first side chains construction that allows communication between proof-of-work blockchains without trusted intermediaries. Our construction is generic in that it allows the passing of any information between blockchains. Using this construction, two blockchains can be connected in a “two-way peg” in which an asset can be transferred from one chain to another and back. We pinpoint the features needed for two chains to communicate: On the source side, a proof-of-work blockchain that has been interlinked, potentially with a velvet fork; on the destination side, a blockchain with smart contract support. We put forth the smart contracts needed to implement these sidechains and explain them in detail. In the heart of our construction, we use a recently introduced cryptographic primitive, Non-Interactive Proofs of Proof-of-Work (NIPoPoWs).
Original languageEnglish
Title of host publicationFinancial Cryptography and Data Security
Number of pages14
ISBN (Electronic)9783030437251
ISBN (Print)9783030437244
Publication statusPublished - 13 Mar 2020
EventFinancial Cryptography and Data Security 2019 - St. Kitts Marriott Resort, St Kitts, Saint Kitts and Nevis
Duration: 18 Feb 201922 Feb 2019


ConferenceFinancial Cryptography and Data Security 2019
Abbreviated titleFC 2019
Country/TerritorySaint Kitts and Nevis
CitySt Kitts
Internet address

Keywords / Materials (for Non-textual outputs)

  • blockchain
  • sidechains
  • NIPoPoWs


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