.png){kind=icon}
.png){kind=icon}
Return
Bhra-VITARIT: Weighted Atomic Swaps for Threshold Services on Scriptless Blockchains
.png){kind=icon}
PRE
AI
K
J
L
X
D
DOI：10.1109/tifs.2026.3714113.png)
.png){kind=icon}
Original request for help.png){kind=icon}
Share.png){kind=icon}
Save
Abstract
En 中文
Atomic swaps serve as a foundational mechanism for trustless digital asset exchange and offer a secure alternative to centralized cryptocurrency exchanges. Although atomic swap protocols have been widely studied, practical implementation remains challenging in real-world systems with limited scripting capabilities such as Bitcoin’s UTXO model. This is especially non-trivial without smart contracts, as we wish to atomic swap only the required threshold of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$t+1$ </tex-math></inline-formula> out of the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$m$ </tex-math></inline-formula> servers offering the service together. Furthermore, most existing atomic swap protocols assume that all participants have equal authority, overlooking scenarios where nodes possess different weights or roles in the transaction process. This limitation becomes increasingly significant in decentralized systems like Proof-of-Stake blockchains, where weighted participation directly affects both security and fairness. Towards this, we propose Bhra-VITARIT (a sanskrit word for “weighted and distributed”), the first atomic swap protocol that is weighted, minimizes reliance on scripting, and is compatible with any digital signature scheme as well as a broad range of currencies (more than the state of the art). Our protocol enables a client to obtain a signature from a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$t$ </tex-math></inline-formula>-out-of-<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$m$ </tex-math></inline-formula> weighted, timed-release threshold service (e.g., using BLS) by directly initiating an atomic swap. Crucially, this mechanism relies solely on minimal signature verification, making it immediately compatible with Bitcoin-like systems. To assess the feasibility of our design, we implemented and benchmarked a prototype of our protocol instantiated with Schnorr/BLS signatures. Our evaluation shows that the client-side validation of partial evaluation results runs in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$O(1)$ </tex-math></inline-formula> time complexity, consistently taking 8.93 ms regardless of the number of servers. Furthermore, even on blockchains with expressive smart contracts such as Ethereum, our protocol reduces on-chain verification gas consumption for 4096 servers from 21M to 786K, representing a reduction of over 96.3% compared to traditional multi-party atomic swap schemes.
Keywords:
Atomic swaps
weighted and distributed
bitcoin
threshold service
Journal
IF:
8
Papers:
5.2K
Citations:
2.3W
Organization
Cited Papers