Two YACL talks next week: Ariel Gabizon (Aztec Labs) + Joachim Neu (a16z Crypto Research)

[Aviv Yaish]

Hi all,

Next week we'll have two exciting talks:

1. Ariel Gabizon (Aztec Labs) - Revisiting the IPA-sumcheck connection

- Time: 1pm, Sep 10

- Abstract: Inner Product Arguments (IPA) [BCC+16,BBB+17] are a family of proof systems  with O(log n) sized proofs, O(n) time verifiers, and transparent setup. Bootle, Chiesa and Sotiraki [BCS21] observed that an IPA can be viewed as a sumcheck protocol [LFKN92] where the summed polynomial is allowed to have coefficients in a group rather than a field. We leverage this viewpoint to improve the performance of multi-linear polynomial commitments  based on IPA. Specifically, - We introduce a simplified variant of Halo-style accumulation that works for multilinear evaluation claims, rather than only univariate ones as in [BGH19,BCMS20]. - We show that the size n MSM the IPA verifier performs can be replaced by a  ``group variant'' of basefold[ZCF23]. This reduces the verifier complexity from O(n) to O(λ*log^2 n).

- Link: https://ia.cr/2025/1325

- Bio: Ariel is currently Chief Scientist at Aztec Labs. He holds a PhD in Theoretical Computer Science from the Weizmann Institute. He transitioned from pure theory to applied ZK working in Eli Ben-Sasson's lab on STARKs. Joined Zcash in 2016 to help with the first-ever SNARK trusted setup and real-life deployment and working in the applied ZK space since. Co-author of PlonK.

- Livestream: https://yale.zoom.us/j/94021055672?pwd=cwBArsrvutKNfBB6gZRtKburCXscqA.1

2. Joachim Neu (a16z Crypto Research) - The Role of Clients in Consensus

- Time: 11am, Sep 12

- Abstract: A specter is haunting consensus protocols—the specter of adversary majority. Dolev and Strong in 1983 showed an early possibility for up to 99% adversaries. Yet, other works show impossibility results for adversaries above 50% under synchrony, seemingly the same setting as Dolev and Strong's. What gives? It is high time that we pinpoint a key culprit for this ostensible contradiction: the modeling details of clients. Are the clients sleepy or always-on? Are they silent or communicating? Can validators be sleepy too? We systematize models for consensus across four dimensions (sleepy/always-on clients, silent/communicating clients, sleepy/always-on validators, and synchrony/partial-synchrony), some of which are new, and tightly characterize the achievable safety and liveness resiliences with matching possibilities and impossibilities for each of the sixteen models. To this end, we unify folklore and earlier results, and fill gaps left in the literature with new protocols and impossibility theorems.

- Link: https://ia.cr/2024/1799

- Bio: I am a post-doc Research Partner at a16z Crypto Research led by Tim Roughgarden. Previously, I earned a PhD from Stanford, advised by David Tse. My current research focus is blockchain-era consensus and decentralized-systems security. My broader interests include distributed computing and systems, applied cryptography, and networking and communications.

- Livestream: https://yale.zoom.us/j/96658818920?pwd=6ySlTppx1QplyvraknGwXAdpgyJOkG.1

As always, more details are available in: https://sites.google.com/view/yacl/seminar

Aviv