Paper 2019/986 Original: eprint.iacr.org/2019/986 ↗

Outpost: A Responsive Lightweight Watchtower

Majid Khabbazian
Tejaswi Nadahalli
Roger Wattenhofer
Abstract

In the context of second layer payments in Bitcoin, and specifically the Lightning Network, we propose a design for a lightweight watchtower that does not need to store signed justice transactions. We alter the structure of the opening and commitment transactions in Lightning channels to encode justice transactions as part of the commitment transactions. With that, a watchtower just needs to watch for specific cheating commitment transaction IDs on the blockchain and can extract signed justice transactions directly from these commitment transactions that appear on the blockchain. Our construction saves an order of magnitude in storage over existing watchtower designs. In addition, we let the watchtower prove to each channel that it has access to all the data required to do its job, and can therefore be paid-per-update.

Metadata
Available format(s)
PDF
Category
Applications
Publication info
Preprint.
History
2019-09-02: last updated
2019-09-02: published
Short URL
https://ia.cr/2019/986
License
https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2019/986,
      author = {Majid Khabbazian and Tejaswi Nadahalli and Roger Wattenhofer},
      title = {Outpost: A Responsive Lightweight Watchtower},
      howpublished = {Cryptology {ePrint} Archive, Paper 2019/986},
      year = {2019},
      url = {https://eprint.iacr.org/2019/986}
}
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