SurferMonkey: a decentralized anonymous Blockchain intercommunication system via Zero Knowledge Proofs.

Blockchain intercommunication systems listen to messages from Blockchain A and insert them in Blockchain B. This interoperability promotes innovation, unlocks liquidity and access to assets. As of March 2022, the Total Value Locked (TVL) in these systems was of $21.8 billion [22]. However, Blockchains are isolated systems that originally were not designed for interoperability. This makes cross-chain communication (Bridges) insecure by nature. More precisely, cross-chain systems face security challenges in terms of selfish Rational Players from a Game Theory perspective, Maximal Exctractable Value (MEV) and Censorship. As of July 2022, the top 3 Bridge hacks account for more than$1.5 billion in losses [20] and the aggregated value extracted from the users using MEV techniques is $663 million [12]. We propose to solve these challenges by using Zero Knowledge Proofs (ZKPs) for cross-chain communication. However, an agnostic anonymous cross-chain communication is more complex than an anonymous single-chain payment, or than a public cross-chain message, as user privacy must be preserved against on/off-chain analysis. Our first contribution is the Decentralized Anonymous Agnostic Cross-Chain Transfer (DACT) protocol. The DACT protocol is a global solution for the anonymity and security challenges of agnostic Blockchain intercommunication. The DACT messages break the on/off-chain analysis thanks to ZKPs. Our second contributions is SurferMonkey, a decentralized infrastructure that supports the DACT protocol. Since SurferMonkey works at the Blockchain application layer, any dApp can use SurferMonkey and send any type of message to a dApp on another Blockchain. Users cannot be censored, nor be exposed to MEV. By applying decentralized proactive security, we obtain resilience against selfish Rational Players, and raise the security bar against cyberattacks. We have implemented a Proof of Concept (PoC) of SurferMonkey by reverse engineering Tornadocash and by applying IDEN3 ZKP circuits. SurferMonkey opens new projects, ranging from anonymous voting and gaming, to a new phase of Anonymous Decentralized Finance (aDeFi)

Systematizing Decentralization and Privacy: Lessons from 15 Years of Research and Deployments

Decentralized systems are a subset of distributed systems where multiple authorities control different components and no authority is fully trusted by all. This implies that any component in a decentralized system is potentially adversarial. We revise fifteen years of research on decentralization and privacy, and provide an overview of key systems, as well as key insights for designers of future systems. We show that decentralized designs can enhance privacy, integrity, and availability but also require careful trade-offs in terms of system complexity, properties provided, and degree of decentralization. These trade-offs need to be understood and navigated by designers. We argue that a combination of insights from cryptography, distributed systems, and mechanism design, aligned with the development of adequate incentives, are necessary to build scalable and successful privacy-preserving decentralized systems

Enhancing Auction Systems with Blockchain Technology

This research paper examines the use of blockchain technology in auction systems. Traditional auction systems face issues related to trust, transparency, and security. Blockchain offers a decentralized and immutable solution that can enhance the efficiency, security, and transparency of auctions. The paper provides an overview of blockchain technology and identifies the challenges in traditional auctions that blockchain can address. It explores existing blockchain-based auction systems and evaluates their effectiveness in mitigating issues such as bid manipulation and fraud. The impact of blockchain on auction participants is also discussed, including benefits like increased trust and reduced transaction costs, as well as challenges related to adoption and scalability. The paper considers both theoretical and practical aspects, analyzing case studies and implementation challenges. It concludes by summarizing the key findings and suggesting future research directions to advance the application of blockchain in auction systems. The auction contract allows users to place bids and determine the highest bidder within a specified time period. The contract also provides functionality for canceling the auction and finalizing it by transferring the funds to the appropriate recipients