Opinion and research articles

The Dawn of Hybrid Layer 2 Protocols by Vitalik Buterin.

Quadratic voting with sortition: Vitalik on economics.

Ethereum Smart Contracts in L2: Optimistic Rollup by Karl Floersch. This post outlines optimistic rollup: a construction which enables autonomous smart contracts on layer 2 (L2) using the OVM. The construction borrows heavily from both plasma and zkRollup designs, and builds on shadow chains as described by Vitalik. This construction resembles plasma but trades off some scalability to enable running fully general (eg. Solidity) smart contracts in layer 2, secured by layer 1. Scalability is proportional to the bandwidth of data availability oracles which include Eth1, Eth2, or even Bitcoin Cash or ETC — providing a near term scalable EVM-like chain in layer 2.

Low-overhead secret single-leader election by Justin Drake. Secret single-leader election with per block overhead of one SNARK plus 32 bytes.

Empirically Analyzing Ethereum’s Gas Mechanism by Renlord Yang, Toby Murray, Paul Rimba, Udaya Parampalli: Ethereum’s Gas mechanism attempts to set transaction fees in accordance with the computational cost of transaction execution: a cost borne by default by every node on the network to ensure correct smart contract execution. Gas encourages users to author transactions that are efficient to execute and in so doing encourages node diversity, allowing modestly resourced nodes to join and contribute to the security of the network. However, the effectiveness of this scheme relies on Gas costs being correctly aligned with observed computational costs in reality. In this work, the authors performed the first large scale empirical study to understand to what degree this alignment exists in practice, by collecting and analyzing Tera-bytes worth of nanosecond-precision transaction execution traces. Besides confirming potential denial-of-service vectors, their results also shed light on the role of I/O in transaction costs which remains poorly captured by the current Gas cost model. Finally, their results suggest that under the current Gas cost model, nodes with modest computational resources are disadvantaged compared to their better resourced peers, which they identify as an ongoing threat to node diversity and network decentralization.

ETHDKG: Distributed Key Generation with Ethereum Smart Contracts by Philipp Schindler and Aljosha Judmayer and Nicholas Stifter and Edgar Weippl: Distributed key generation (DKG) is a fundamental building block for a variety of cryptographic schemes and protocols, such as threshold cryptography, multi-party coin tossing schemes, public randomness beacons and consensus protocols. More recently, the surge in interest for blockchain technologies, and in particular the quest for developing scalable protocol designs, has renewed and strengthened the need for efficient and practical DKG schemes. Surprisingly, given the broad range of applications and available body of research, fully functional and readily available DKG protocol implementations still remain limited. The authors hereby aim to close this gap by presenting an open source, fully functional, well documented, and economically viable DKG implementation that employs Ethereum’s smart contract platform as a communication layer. The efficiency and practicability of our protocol is demonstrated through the deployment and successful execution of a DKG contract in the Ropsten testnet. Given the current Ethereum block gas limit, it is possible to support up to 256 participants, while still ensuring that the key generation process can be verified at smart contract level. Further, they present a generalization of our underlying DKG protocol that is suitable for distributed generation of keys for discrete logarithm based cryptosystems.

A Survey on Ethereum Systems Security: Vulnerabilities, Attacks and Defenses by Huashan Chen, Marcus Pendleton, Laurent Njilla, and Shouhuai Xu: The blockchain technology is believed by many to be a game changer in many application domains, especially financial applications. While the first generation of blockchain technology (i.e., Blockchain 1.0) is almost exclusively used for cryptocurrency purposes, the second generation (i.e., Blockchain 2.0), as represented by Ethereum, is an open and decentralized

platform enabling a new paradigm of computing — DApps running on top of blockchains. The rich applications and semantics of DApps inevitably introduce many security vulnerabilities, which have no counterparts in pure cryptocurrency systems like Bitcoin. Since Ethereum is a new, yet complex, system, it is imperative to have a systematic and comprehensive understanding on its security from a holistic perspective, which is unavailable. To the best of our knowledge, the present survey, which can also be used as a tutorial, fills this void. In particular, the authors systematize three aspects of Ethereum systems security: vulnerabilities, attacks, and defenses. They draw insights into, among other things, vulnerability root causes, attack consequences, and defense capabilities, which shed light on future research directions.

Versionless Ethereum Virtual Machine by Wei Tang.

Some privacy proposals:

Anonymity: a ZKP to remove the mapping ip address / wallet’s public key of a validator.

Privacy-Preserving Casper FFG using Traceable Ring Signatures.