Georgios "George" Kadianakis (Greek: Γιώργος Καδιανάκης) is a Greek cryptographer and core protocol researcher at the Ethereum Foundation. ^{[1] [2]} He is recognized for his work on zero-knowledge proofs (ZKPs), the development of core Ethereum infrastructure, and his co-creation of the Equihash proof-of-work algorithm. Kadianakis has also made significant contributions to the security and scalability of the Tor anonymity network. ^{[1] [3]}​

Education

Kadianakis earned a Diploma in Electrical and Computer Engineering from the National Technical University of Athens. He later attended University College London (UCL), where he received a Master of Science (M.Sc.) in Information Security and a Doctor of Philosophy (Ph.D.) in Computer Science with a specialization in cryptography. ^[2]

Career

During his academic tenure, Kadianakis served as a Research Assistant at University College London. After completing his doctorate, he was a Postdoctoral Researcher at the University of Luxembourg, where he was a member of the CryptoLux research group. ^[2] Throughout this period, he was an active contributor to the Tor Project, an open-source initiative focused on enabling anonymous communication. ^[1]​

In October 2018, Kadianakis joined the Ethereum Foundation as a cryptographer and protocol researcher. ^[1] He is a member of the foundation's core cryptography team as well as the Go Ethereum (Geth) team, focusing on the security and efficiency of Ethereum's consensus layer and the implementation of advanced cryptographic primitives. ^{[1] [2]}​

Major Works and Research

As of early 2026, Kadianakis has authored and co-authored numerous academic papers, accumulating over 1,300 citations. His research spans proof-of-work systems, anonymity networks, and zero-knowledge proof constructions. ^[3]​

Pre-Ethereum Research

Equihash Algorithm

In 2016, Kadianakis co-authored the paper "Equihash: Asymmetric proof-of-work based on the generalized birthday problem" with Alex Biryukov and Dmitry Khovratovich. The paper introduced Equihash, a memory-hard proof-of-work algorithm designed to be resistant to the performance advantages of specialized ASIC hardware. The algorithm was subsequently adopted by the privacy-focused cryptocurrency Zcash and other digital currencies. ^{[2] [3]}​

Tor Project Contributions

Kadianakis is the creator and a key developer of Onionbalance, a system that provides load-balancing and high availability for Tor onion services, enhancing their reliability and resilience. His academic research on the network includes co-authoring papers that identified potential vulnerabilities and areas for improvement. Notable works include "Vanguards: a framework for long-term deanonymization attacks in Tor" (2016), which analyzed methods for compromising user anonymity over time, and "Torsk: A tool for scalably fingerprinting Tor hidden services" (2017). ^{[1] [3]}​

Zcash Anonymity Analysis

Following his work on Equihash, Kadianakis co-authored "On the anonymity of the Zcash protocol" in 2018. The paper provided an academic analysis of the privacy guarantees offered by the Zcash protocol, identifying potential linkage heuristics that could compromise user anonymity under certain conditions. ^{[2] [3]}​

Ethereum Protocol Development

At the Ethereum Foundation, Kadianakis's work has been central to the research and development of technologies for scaling the network and improving its long-term security.

Zero-Knowledge Proofs (ZKPs)

Kadianakis has focused extensively on advancing the state of ZKPs for use in the Ethereum ecosystem. In 2025, he co-authored the paper "Recursion-friendly SNARKs for arguments of Bounded-depth" with Dankrad Feist and Vitalik Buterin. The work proposed a new SNARK construction optimized for recursion, a critical feature for building scalable zk-Rollups and zkEVMs. The design prioritizes a fast prover and small proof sizes, making it highly suitable for blockchain applications. ^[2]​

His other contributions in this area include the creation of soundcalc, a universal calculator for analyzing the soundness of hash-based zkEVMs, and the development of Curdleproofs, a novel and efficient zero-knowledge shuffle argument published in 2022 with applications in privacy-preserving systems like anonymous voting. ^{[1] [3]}​

Core Infrastructure and Upgrades

Kadianakis has been involved in several key upgrades and strategic shifts for the Ethereum protocol.

• EIP-4844 (Proto-Danksharding): He was a key contributor to c-kzg-4844, the minimal C language implementation of the cryptographic APIs required for Proto-Danksharding. This work on Kate-Zaverucha-Goldberg (KZG) polynomial commitments was fundamental to the Deneb upgrade, which aimed to significantly reduce transaction fees for Layer 2 rollups by introducing a new data transaction type known as "blobs." ^{[1] [2]}
• Verkle Trees: Kadianakis has been involved in the research and planning for the implementation of Verkle trees, a data structure upgrade aimed at enabling statelessness on Ethereum. He has publicly supported a measured approach to its deployment, emphasizing long-term stability. In a public discussion, he stated, "Delaying this is a good trade a year from now for a solid verkle feature that will serve us for the next 10 years." ^[1]
• Consensus Layer Security: In a paper published in January 2025, "Peer-evaluations and DA for better attestation aggregation," Kadianakis and his co-authors proposed a new mechanism to improve the efficiency and security of attestation aggregation on Ethereum's consensus layer. The proposal uses peer evaluations and a data-availability-based blacklist to create a more robust "market for aggregators" and mitigate potential timing attacks. ^[5]

zkEVM Security Roadmap

In late 2025, Kadianakis played a central public-facing role in announcing a strategic shift in the Ethereum Foundation's priorities for zkEVM development, moving from a focus on speed to an emphasis on provable security. On December 12, 2025, he announced a new 2026 roadmap for zkEVMs, which he termed the "2026 boss: 128-bit provable security." ^{[4] [2]}​

The roadmap established three milestones for zkEVM teams to achieve by the end of 2026, culminating in attaining 128-bit security with proof sizes under 300 kilobytes. This initiative was framed as the next major challenge for zkEVMs after many had successfully achieved real-time proving. In a statement, Kadianakis explained the long-term vision for this effort: "Once teams have hit these targets and zkVM architectures stabilize, the formal verification work we’ve been investing in can reach its full potential." ^[2]​