Zero-Knowledge Shuffle Improvement in Ethereum Single Secret Leader Election

Holmgaard, Oliver ; Jakobsen, Anders Malta

4. term

Computer Science, Master

2025

2025-06-12

18 pages

Ethereum er en af de førende Proof-of-Stake blockchains. Dog er den stadig sårbar overfor angreb. Et af disse angreb er deanonymiserings-angrebet af Heimbach et al., hvor en ondsindet aktør kan få fat i validatorernes IP-adresser, hvorefter et Denial-of-Service angreb kan udføres. I et forsøg på at bekæmpe dette angreb har Ethereum foreslået brugen af Whisk-protokollen. Whisk er en Single Secret Leader Election protokol, der bruger et Zero-Knowledge bevis, kaldet Curdleproofs, hvilket bruger Indre Produkt Argumenter til at bevise validiteten af en blanding af validatorer. Denne artikel forbedrer Curdleproofs' Indre Produkt Argument ved introduktionen af CAAUrdleproofs, en modificeret version af Curdleproofs, der inkorporerer ideer fra Springproofs til at adressere begrænsningerne ved Curdleproofs med hensyn til blandingsstørrelse. Vi viser, at CAAUrdleproofs har lignende bevis- og verifikationstider som Curdleproofs, når blandingsstørrelsen er en toerpotens. Vi demonstrerer også, at CAAUrdleproofs har en fordel i præstation for enhver blandingsstørrelse, der ikke er en toerpotens, og at denne fordel øges, jo lavere den er under en toerpotens. Efter at have udført eksperimenter foreslår vi også en ny blandingsstørrelse, der er mindre end den nuværende i Curdleproofs, hvilket resulterer i en mindre omkostning i blokstørrelsen end i den nuværende Curdleproofs protokol. Vi har gjort dette og stadig bevaret validatorernes anonymitet.

Ethereum is one of the leading Proof-of-Stake blockchains. However, it is still vulnerable to attacks. One such attack is the de-anonymization attack by Heimbach et al., where an adversary can obtain validator IP addresses and then perform a Denial-of-Service attack on them. To try and combat this attack, Ethereum has proposed the use of the Whisk protocol. Whisk is a Single Secret Leader Election protocol that uses a zero-knowledge proof called Curdleproofs that uses Inner Product Arguments to prove the validity of a shuffle of validators. This paper improves upon Curdleproofs' Inner Product Arguments by introducing CAAUrdleproofs, a modified version of Curdleproofs incorporating ideas from Springproofs to address the limitations of Curdleproofs regarding shuffle size. We show that CAAUrdleproofs has similar proving and verifying times to Curdleproofs when the shuffle size is a power of two. We also demonstrate that CAAUrdleproofs has a performance advantage for any shuffle size that is not a power of two and that this advantage increases as the shuffle size decreases below a power of two. After performing experiments, we also suggest a new shuffle size, which is smaller than the current one used in Curdleproofs, resulting in a more negligible block overhead than the one created by the current Curdleproofs protocol. All this is done while still preserving the anonymity of validators.

Ethereum ; Distribuerede Systemer ; Proof of Shuffle ; Indre Produkt Argument ; Zero-Knowledge bevis ; Single Secret Leader Election

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