Unstoppable Wallets: Chain-assisted Threshold ECDSA and its Applications
The security and usability of cryptocurrencies and other blockchain-based applications depend on the secure management of cryptographic keys. However, current approaches for managing these keys often rely on third parties, trusted to be available at a minimum, and even serve as custodians in some so...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
ACM
2024
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| Online Access: | https://hdl.handle.net/1721.1/155455 |
| _version_ | 1811084040484159488 |
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| author | Zyskind, Guy Yanai, Avishay Pentland, Alex |
| author_facet | Zyskind, Guy Yanai, Avishay Pentland, Alex |
| author_sort | Zyskind, Guy |
| collection | MIT |
| description | The security and usability of cryptocurrencies and other blockchain-based applications depend on the secure management of cryptographic keys. However, current approaches for managing these keys often rely on third parties, trusted to be available at a minimum, and even serve as custodians in some solutions, creating single points of failure and limiting the ability of users to fully control their own assets. In this work we first revisit the problem of threshold ECDSA by considering the commonly admissible 'server-aided' model, namely, the presence of a semi-honest and non-colluding service provider. Then, we leverage that model and consider cases where that 'server' is distributed, introducing the novel concept of unstoppable wallets; hence eliminating any single point of failure. Unstoppable wallets are programmable threshold ECDSA wallets that allow users to co-sign transactions with a confidential smart contract, rather than a singular third-party. We construct highly efficient threshold ECDSA protocols that form the basis of unstoppable wallets and prove their security in the server-aided model, achieving the standard notion of fairness and robustness even in case of a dishonest majority among the signers. Our protocols minimize the write-complexity for threshold ECDSA key-generation and signing, while reducing communication and computation overhead.
We provide a proof-of-concept implementation of these protocols, written in a smart contract language, deployed on the Secret Network - a blockchain that plays the role of the server. Using that deployment, we showcase the protocols' applicability for two interesting applications, policy checking and wallet exchange, as well as their efficiency by demonstrating low gas costs and fees. |
| first_indexed | 2024-09-23T12:43:42Z |
| format | Article |
| id | mit-1721.1/155455 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T12:43:42Z |
| publishDate | 2024 |
| publisher | ACM |
| record_format | dspace |
| spelling | mit-1721.1/1554552024-09-22T04:38:04Z Unstoppable Wallets: Chain-assisted Threshold ECDSA and its Applications Zyskind, Guy Yanai, Avishay Pentland, Alex The security and usability of cryptocurrencies and other blockchain-based applications depend on the secure management of cryptographic keys. However, current approaches for managing these keys often rely on third parties, trusted to be available at a minimum, and even serve as custodians in some solutions, creating single points of failure and limiting the ability of users to fully control their own assets. In this work we first revisit the problem of threshold ECDSA by considering the commonly admissible 'server-aided' model, namely, the presence of a semi-honest and non-colluding service provider. Then, we leverage that model and consider cases where that 'server' is distributed, introducing the novel concept of unstoppable wallets; hence eliminating any single point of failure. Unstoppable wallets are programmable threshold ECDSA wallets that allow users to co-sign transactions with a confidential smart contract, rather than a singular third-party. We construct highly efficient threshold ECDSA protocols that form the basis of unstoppable wallets and prove their security in the server-aided model, achieving the standard notion of fairness and robustness even in case of a dishonest majority among the signers. Our protocols minimize the write-complexity for threshold ECDSA key-generation and signing, while reducing communication and computation overhead. We provide a proof-of-concept implementation of these protocols, written in a smart contract language, deployed on the Secret Network - a blockchain that plays the role of the server. Using that deployment, we showcase the protocols' applicability for two interesting applications, policy checking and wallet exchange, as well as their efficiency by demonstrating low gas costs and fees. 2024-07-08T18:07:23Z 2024-07-08T18:07:23Z 2024-07 2024-07-01T07:56:58Z Article http://purl.org/eprint/type/ConferencePaper 979-8-4007-0482-6 https://hdl.handle.net/1721.1/155455 Zyskind, Guy, Yanai, Avishay and Pentland, Alex. 2024. "Unstoppable Wallets: Chain-assisted Threshold ECDSA and its Applications." PUBLISHER_POLICY en 10.1145/3634737.3637657 Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The author(s) application/pdf ACM Association for Computing Machinery |
| spellingShingle | Zyskind, Guy Yanai, Avishay Pentland, Alex Unstoppable Wallets: Chain-assisted Threshold ECDSA and its Applications |
| title | Unstoppable Wallets: Chain-assisted Threshold ECDSA and its Applications |
| title_full | Unstoppable Wallets: Chain-assisted Threshold ECDSA and its Applications |
| title_fullStr | Unstoppable Wallets: Chain-assisted Threshold ECDSA and its Applications |
| title_full_unstemmed | Unstoppable Wallets: Chain-assisted Threshold ECDSA and its Applications |
| title_short | Unstoppable Wallets: Chain-assisted Threshold ECDSA and its Applications |
| title_sort | unstoppable wallets chain assisted threshold ecdsa and its applications |
| url | https://hdl.handle.net/1721.1/155455 |
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