As aforementioned, the privacy protection in the cross-chain system has been a desirable issue. For some privacy-related scenarios, a non-interactive zero-knowledge (NIZK) technique can be used to protect the users’ sensitive data (Lu et al., Zebralancer: private and anonymous crowdsourcing system atop open blockchain. In: ICDCS 2018. IEEE Computer Society, Washington, pp 853–865, 2018; Lu et al., Dragoon: private decentralized hits made practical. In: ICDCS 2020. IEEE, Piscataway, pp 910–920, 2020), allowing one party to prove to another party that they know a certain piece of information without revealing the information itself. Zero-knowledge succinct non-interactive argument of knowledge (zkSNARK) is one of the earliest and most popular zero-knowledge proof implementations. In order to launch a zkSNARK network, a trusted setup is required, in which multiple parties each generate a partial key to launch the network and then destroy the key afterwards (Ben-Sasson et al., Snarks for C: verifying program executions succinctly and in zero knowledge. In: Canetti R, Garay JA (eds) CRYPTO 2013. Lecture Notes in Computer Science, vol 8043. Springer, Berlin, pp 90–108, 2013; Groth, On the size of pairing-based non-interactive arguments. In: Fischlin M, Coron JS (eds) Advances in cryptology – EUROCRYPT 2016. Springer, Berlin, pp 305–326, 2016). zkSNARK can be further improved by replacing the costly setup with an updatable and universal setup, such as Sonic (Maller et al., Sonic: zero-knowledge snarks from linear-size universal and updateable structured reference strings. IACR; 2019, p 99), PLONK (Gabizon A et al., PLONK: permutations over lagrange-bases for oecumenical noninteractive arguments of knowledge. IACR 2019, p 953), and Lunar (Campanelli et al., Lunar: a toolbox for more efficient universal and updatable zksnarks and commit-and-prove extensions. In: Tibouchi M, Wang H (eds) ASIACRYPT 2021, LNCS, vol 13092. Springer, Berlin, 2021, pp 3–33). However, the universal setup is still not practical without a trusted third party, which breaks the decentralized property of the blockchain systems. The zero-knowledge scalable and transparent argument of knowledge (zkSTARK) (Ben-Sasson et al., Scalable, transparent, and post-quantum secure computational integrity. IACR 2018, p 46) uses public and random parameters to generate proofs, which completely removes the need for a trusted third party or a costly multi-party computation. Unfortunately, the proof size of zkSTARK is much larger than existing approaches. As the proofs need to be transmitted over the whole network and stored for a long time, zkSTARK incurs high communication and storage overhead. How to achieve lightweight privacy preserving for cross-chain transaction?

Lightweight Cross-Chain Privacy-Preserving Protocol

章节
发表日期：

2025年

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Peng Jiang,
Liehuang Zhu

摘要

As aforementioned, the privacy protection in the cross-chain system has been a desirable issue. For some privacy-related scenarios, a non-interactive zero-knowledge (NIZK) technique can be used to protect the users’ sensitive data (Lu et al., Zebralancer: private and anonymous crowdsourcing system atop open blockchain. In: ICDCS 2018. IEEE Computer Society, Washington, pp 853–865, 2018; Lu et al., Dragoon: private decentralized hits made practical. In: ICDCS 2020. IEEE, Piscataway, pp 910–920, 2020), allowing one party to prove to another party that they know a certain piece of information without revealing the information itself. Zero-knowledge succinct non-interactive argument of knowledge (zkSNARK) is one of the earliest and most popular zero-knowledge proof implementations. In order to launch a zkSNARK network, a trusted setup is required, in which multiple parties each generate a partial key to launch the network and then destroy the key afterwards (Ben-Sasson et al., Snarks for C: verifying program executions succinctly and in zero knowledge. In: Canetti R, Garay JA (eds) CRYPTO 2013. Lecture Notes in Computer Science, vol 8043. Springer, Berlin, pp 90–108, 2013; Groth, On the size of pairing-based non-interactive arguments. In: Fischlin M, Coron JS (eds) Advances in cryptology – EUROCRYPT 2016. Springer, Berlin, pp 305–326, 2016). zkSNARK can be further improved by replacing the costly setup with an updatable and universal setup, such as Sonic (Maller et al., Sonic: zero-knowledge snarks from linear-size universal and updateable structured reference strings. IACR; 2019, p 99), PLONK (Gabizon A et al., PLONK: permutations over lagrange-bases for oecumenical noninteractive arguments of knowledge. IACR 2019, p 953), and Lunar (Campanelli et al., Lunar: a toolbox for more efficient universal and updatable zksnarks and commit-and-prove extensions. In: Tibouchi M, Wang H (eds) ASIACRYPT 2021, LNCS, vol 13092. Springer, Berlin, 2021, pp 3–33). However, the universal setup is still not practical without a trusted third party, which breaks the decentralized property of the blockchain systems. The zero-knowledge scalable and transparent argument of knowledge (zkSTARK) (Ben-Sasson et al., Scalable, transparent, and post-quantum secure computational integrity. IACR 2018, p 46) uses public and random parameters to generate proofs, which completely removes the need for a trusted third party or a costly multi-party computation. Unfortunately, the proof size of zkSTARK is much larger than existing approaches. As the proofs need to be transmitted over the whole network and stored for a long time, zkSTARK incurs high communication and storage overhead. How to achieve lightweight privacy preserving for cross-chain transaction?