69.6CEMar 23
ParlayMarket: Automated Market Making for Parlay-style Joint ContractsRanvir Rana, Viraj Nadkarni, Niusha Moshrefi et al.
Prediction markets are powerful mechanisms for information aggregation, but existing designs are optimized for single-event contracts. In practice, traders frequently express beliefs about joint outcomes - through parlays in sports, conditional forecasts across related events, or scenario bets in financial markets. Current platforms either prohibit such trades or rely on ad hoc mechanisms that ignore correlation structure, resulting in inefficient prices and fragmented liquidity. We introduce ParlayMarket, the first automated market-making design that supports parlay-style joint contracts within a unified liquidity pool while maintaining coherent pricing across base markets and their combinations. Our main result is a convergence characterization of the resulting system. Under repeated trading, the AMM dynamics converge to a unique fixed point corresponding to the best approximation to the true joint distribution within the model class. We show that (i) parameter error remains bounded at stationarity due to a balance between signal and noise in trade-induced updates, and (ii) pricing error and monetary loss scale with this parameter error, implying that aggregate market-maker loss remains controlled and grows at most quadratically in the number of base markets. These results establish explicit limits on the information-retrieval error achievable through the trading interface. Importantly, parlay trades play a structural role in this convergence: by providing direct constraints on joint outcomes, they improve identifiability of dependence structure and reduce steady-state error relative to markets that rely only on marginal trades. Empirically, we show both in controlled simulations and in replay on historical Kalshi parlay data that this design achieves the intended scaling while remaining effective in realistic market settings.
AINov 1, 2024
OML: A Primitive for Reconciling Open Access with Owner Control in AI Model DistributionZerui Cheng, Edoardo Contente, Ben Finch et al.
The current paradigm of AI model distribution presents a fundamental dichotomy: models are either closed and API-gated, sacrificing transparency and local execution, or openly distributed, sacrificing monetization and control. We introduce OML(Open-access, Monetizable, and Loyal AI Model Serving), a primitive that enables a new distribution paradigm where models can be freely distributed for local execution while maintaining cryptographically enforced usage authorization. We are the first to introduce and formalize this problem, introducing rigorous security definitions tailored to the unique challenge of white-box model protection: model extraction resistance and permission forgery resistance. We prove fundamental bounds on the achievability of OML properties and characterize the complete design space of potential constructions, from obfuscation-based approaches to cryptographic solutions. To demonstrate practical feasibility, we present OML 1.0, a novel OML construction leveraging AI-native model fingerprinting coupled with crypto-economic enforcement mechanisms. Through extensive theoretical analysis and empirical evaluation, we establish OML as a foundational primitive necessary for sustainable AI ecosystems. This work opens a new research direction at the intersection of cryptography, machine learning, and mechanism design, with critical implications for the future of AI distribution and governance.
CRDec 6, 2021
LightSync: Ultra Light Client for PoW BlockchainsNiusha Moshrefi, Mahyar Daneshpajooh, Chen Feng
Full nodes in a blockchain network store and verify a copy of the whole blockchain. Unlike full nodes, light clients are low-capacity devices that want to validate certain data on a blockchain. They query the data they want from a full node. If light clients do not verify the data they receive, full nodes might deceive them. SPV, introduced in the Bitcoin paper, is a practical solution to this problem currently used in many PoW blockchains. In SPV, the resources needed to verify a full node's response grow linearly with the blockchain size, making it inefficient over the long run. Another issue with SPV is that the full nodes do not get compensated for the services they provide. In this work, we introduce LightSync, a simple and cost-effective solution for light clients to verify the inclusion of certain data in a PoW blockchain. The resources needed for running LightSync remain constant no matter what the size of the blockchain is. LightSync uses an incentive mechanism that encourages full nodes to participate in the protocol. We perform a thorough analysis of the security of LightSync and discuss the details of deploying it in a real-world environment.
LGFeb 21, 2020
New Bounds For Distributed Mean Estimation and Variance ReductionPeter Davies, Vijaykrishna Gurunathan, Niusha Moshrefi et al.
We consider the problem of distributed mean estimation (DME), in which $n$ machines are each given a local $d$-dimensional vector $x_v \in \mathbb{R}^d$, and must cooperate to estimate the mean of their inputs $μ= \frac 1n\sum_{v = 1}^n x_v$, while minimizing total communication cost. DME is a fundamental construct in distributed machine learning, and there has been considerable work on variants of this problem, especially in the context of distributed variance reduction for stochastic gradients in parallel SGD. Previous work typically assumes an upper bound on the norm of the input vectors, and achieves an error bound in terms of this norm. However, in many real applications, the input vectors are concentrated around the correct output $μ$, but $μ$ itself has large norm. In such cases, previous output error bounds perform poorly. In this paper, we show that output error bounds need not depend on input norm. We provide a method of quantization which allows distributed mean estimation to be performed with solution quality dependent only on the distance between inputs, not on input norm, and show an analogous result for distributed variance reduction. The technique is based on a new connection with lattice theory. We also provide lower bounds showing that the communication to error trade-off of our algorithms is asymptotically optimal. As the lattices achieving optimal bounds under $\ell_2$-norm can be computationally impractical, we also present an extension which leverages easy-to-use cubic lattices, and is loose only up to a logarithmic factor in $d$. We show experimentally that our method yields practical improvements for common applications, relative to prior approaches.