Permacoin: Repurposing Bitcoin Work for Data Preservation

By Andrew K. Miller, Ari Juels, Elaine Shi, Bryan Parno, Jonathan Katz. 2014

300 citations recorded by the source corpus.

Bit coin is widely regarded as the first broadly successful e-cash system. An oft-cited concern, though, is that mining Bit coins wastes computational resources. Indeed, Bit coin's underlying mining mechanism, which we call a scratch-off puzzle (SOP), involves continuously attempting to solve computational puzzles that have no intrinsic utility. We propose a modification to Bit coin that repurposes its mining resources to achieve a more broadly useful goal: distributed storage of archival data. We call our new scheme Perm coin. Unlike Bit coin and its proposed alternatives, Perm coin requires clients to invest not just computational resources, but also storage. Our scheme involves an alternative scratch-off puzzle for Bit coin based on Proofs-of-Retrievability (PORs). Successfully minting money with this SOP requires local, random access to a copy of a file. Given the competition among mining clients in Bit coin, this modified SOP gives rise to highly decentralized file storage, thus reducing the overall waste of Bit coin. Using a model of rational economic agents we show that our modified SOP preserves the essential properties of the original Bit coin puzzle. We also provide parameterizations and calculations based on realistic hardware constraints to demonstrate the practicality of Perm coin as a whole.

Subfields: Computer Networks and Communications, Information Systems

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Citations in the corpus

Biscotti: A Ledger for Private and Secure Peer-to-Peer Machine Learning (2018, background): “Through design elements, such as publicly verifiable proof of work, eventual consistency, and ledger-based consensus, blockchains have been used for a variety of decentralized multi-party tasks such as currency management [23, 38], archival data storage [5, 35] and financial auditing [39].”
Architecture for Blockchain Applications (2019, background): “The original conception of blockchain was first discussed in the Bitcoin paper (Nakamoto 2008). A more complete introduction of blockchain and Bitcoin can be found in Swan (2015) and Antonopoulos (2015).”
A Survey of Blockchain Technology Applied to Smart Cities: Research Issues and Challenges (2019, background): “(PoA) [78], Proof of Retrievability [79], Proof of Burn [80], Proof of Activity [81], Proof of Space [82], Proof of Trust [83], Proof of Luck [84], BFT-SMART [85] and ScalableBFT [86].”
Proof-of-Stake Consensus Mechanisms for Future Blockchain Networks: Fundamentals, Applications and Opportunities (2019, background): “Available: https://eprint.iacr.org/2017/203 [9] A.Miller, A. Juels, E. Shi, B. Parno, and J. Katz, ‘‘Permacoin: Repurposing Bitcoin work for data preservation,’’ in Proc.”
Privacy-Preserving Solutions for Blockchain: Review and Challenges (2019, background): “storage [134]–[138] can be integrated with blockchain by paying blockchain tokens to the honest storage nodes, applying privacy measures to protect the data, and hashes in the transactions for integrity.”
The Blockchain as a Software Connector (2016, methodology): “More recently, Permacoin proposes a modification to Bitcoin [17], which uses “Proof-of-retrievability” to re-purpose Bitcoin’s mining resource to distributed storage of archival data.”
Bitcoin (2015, background): “Some have suggested using alternative proof-of-work procedures that will make specialized hardware less effective and will thus weaken this effect (one such example appears in Miller et al. 21 ).”
A Vademecum on Blockchain Technologies: When, Which, and How (2019, background): “Today these naive implementations are overcame by valid alternatives: some [283], [285] asking validators to lock an amount of coins (proof-ofdeposit), some [278] asking to destroy it (proof-of-burn), and some [286], [287], [288] asking to allocate a significant amount of memory/disk-space (proof-of”
REM: Resource-Efficient Mining for Blockchains (2017, background): “Existing schemes rely on esoteric resources [55], have low recycling rates [63], or are centralized [41].”
A Survey of Distributed Consensus Protocols for Blockchain Networks (2019, unknown): “[129] in 2014.”
SoK: Consensus in the Age of Blockchains (2017, methodology): “ved. Peercoin [9] adapts this approach. B. Proof-of-Capacity In proof-of-capacity, participants vote on new blocks weighted by their capacity to allocate a non-trivial amount of disk space. PermaCoin [102] repurposes Bitcoin’s PoW with a more broadly useful task: providing a robust, distributed stor”
Centrally Banked Cryptocurrencies (2015, background): “Alternative cryptocurrencies, such as Litecoin, try to distribute this cost and Permacoin [18] tries to put the computation cycles to good use, but ultimately neither of these solutions removes the costs.”
Verifiable Delay Functions (2018, unknown): “Examples include proof-of-stake [45, 54, 44, 28, 13], proof-of-space [60], and proof-of-storage [55, 2].”
Blockstack: A Global Naming and Storage System Secured by Blockchains (2016, background): “Storage-oriented cryptocurrency blockchains like Filecoin [23], Permacoin [40], and Storj [50] seek to replace cloud storage by distributing files as sets of transactions within a blockchain, and rewarding miners for proof-of-storage (instead of proof-of-work).”
SoK: Research Perspectives and Challenges for Bitcoin and Cryptocurrencies (2015, background): “[79] proposed a puzzle incorporating proof-of-retreivability, so that mining requires storing a portion of a large public”