我們研究了區塊鍊在（随機經濟）EVR領域的問題，即那些會因為随機而對結果産生重大影響的經濟問題。EVR的應用包括基于區塊鍊的彩票和賭博。EVR源保證：(i)保密性，確定随機位被保密，直到一些預定義的條件表明它們是安全的（例如，彩票的銷售結束）；(ii)穩健性，保證随機位在條件成立後被公布。我們将EVR問題形式化，并在類似Ethereum的區塊鍊抽象後解決，它支援智能合約和可轉移的原生币。随機性是通過分布式開放的送出-揭示方案由博弈論代理産生的，這些代理努力使其持币量最大化。需要注意的是，在經濟環境中，這類代理可能會從打破保密性或穩健性中獲利，并可能為此進行旁門左道協定（通過智能合約）。我們的解決方案建立了一個激勵結構，以對抗這種攻擊。我們證明，遵循該協定會産生一個穩定狀态，稱為聯盟證明納什均衡，沒有一個由玩家子集組成的聯盟可以同意偏離該狀态。在這個穩定狀态下，穩健性和保密性得到了滿足。最後，我們在Ethereum上實作了我們的EVR源。
原文标題：Economically Viable Randomness
原文：We study the problem of providing blockchain applications with economically viable randomness (EVR), namely, randomness that has significant economic consequences. Applications of EVR include blockchain-based lotteries and gambling. An EVR source guarantees (i) secrecy, assuring that the random bits are kept secret until some predefined condition indicates that they are safe to reveal (e.g., the lottery's ticket sale closes), and (ii) robustness, guaranteeing that the random bits are published once the condition holds. We formalize the EVR problem and solve it on top of an Ethereum-like blockchain abstraction, which supports smart contracts and a transferable native coin. Randomness is generated via a distributed open commit-reveal scheme by game-theoretic agents who strive to maximize their coin holdings. Note that in an economic setting, such agents might profit from breaking secrecy or robustness, and may engage in side agreements (via smart contracts) to this end. Our solution creates an incentive structure that counters such attacks. We prove that following the protocol gives rise to a stable state, called Coalition-Proof Nash Equilibrium, from which no coalition comprised of a subset of the players can agree to deviate. In this stable state, robustness and secrecy are satisfied. Finally, we implement our EVR source over Ethereum.
作者：David Yakira, Avi Asayag, Ido Grayevsky, Idit Keidar
連結：https://arxiv.org/abs/2007.03531
經濟上可行的随機性（CS Cryptography and Security）.pdf