Decentralized meetup by Common Prefix
🚀 Our Fourth Decentralized Meetup is Coming Soon!
Join us for more insightful talks, great discussions, and networking over drinks & snacks.
This is our fourth monthly meetup, where blockchain enthusiasts at all levels come together to share insights, explore ideas, and build connections.
For this meetup, we’ve lined up three insightful 30-minute talks:
1. Blockchains and Formal Verification: A match made in heaven? - Orfeas Stefanos Thyfronitis Litos / Researcher @ Common Prefix & Imperial College London // 18:30 - 19:00
Abstract: Practical implementations of blockchains and smart contracts are security-critical, as they safeguard billions of dollars in value while being exposed to the whole internet - any vulnerability is bound to be quickly and irreversibly exploited. To make matters worse, low-level cryptographic libraries are notoriously hard to use correctly, especially when implementations have to guarantee high-level security goals, like safety and liveness. Formally verifying that an actual implementation provides the desired high-level security properties via a machine-checkable proof is the holy grail for high-assurance blockchain code. Nevertheless, formal verification has its own limitations and caveats, as well as adds substantial complexity. In this talk, we will see how formal verification is being used in the industry, what are some ways to introduce it to our development processes while minimizing disruption, what tradeoffs we need to consider, what pitfalls to be alert of, and what advances to be in the lookout for in the future. By the end, we will have a pragmatic understanding of how formal verification can make our systems better and at what cost, empowering us to make informed choices.
2. Protocol Magic: Extending the EVM with Precompiles - João Azevedo / Software Engineer @ Common Prefix // 19:00 - 19:30
Abstract: EVM precompiles allow engineers to embed complex routines—whether advanced cryptographic algorithms, heavy numerical methods, or even on-chain image generation—directly into the client, avoiding the high gas costs and code complexity of loop-heavy Solidity implementations. These native primitives deliver predictable performance, clear gas accounting, and the ability to evolve via hard forks without touching deployed contracts. In this session, we’ll go through the full lifecycle of a precompile: authoring a Rust module, integrating it into an L1 client’s precompile registry, and calling it from a Solidity smart contract. To illustrate its power, we’ll deploy a chart-rendering primitive on a local network that fetches live on-chain data and returns a PNG bar-chart—demonstrating how network-level extensions can unlock always-available, trustless functionality straight from the network, with zero reliance on external services.
3. Walrus: An Efficient Decentralized Storage Network - Alberto Sonnino / Researcher @ Mysten Labs - Sui // 19:30 - 20:00
Abstract: Decentralized storage systems face a fundamental trade-off between replication overhead, recovery efficiency, and security guarantees. Current approaches either rely on full replication, incurring substantial storage costs, or employ trivial erasure coding schemes that struggle with efficient recovery especially under high storage node churn. We present Walrus, a novel decentralized blob storage system that addresses these limitations through multiple technical innovations. At the core of Walrus is Red Stuff, a two-dimensional erasure coding protocol that achieves high security with only 4.5x replication factor, while enabling self-healing recovery that requires bandwidth proportional to only the lost data (𝑂(|𝑏𝑙𝑜𝑏|/𝑛)versus 𝑂(|𝑏𝑙𝑜𝑏|)in traditional systems). Crucially, Red Stuff is the first protocol to support storage challenges in asynchronous networks, preventing adversaries from exploiting network delays to pass verification without actually storing data. Walrus also introduces a novel multi-stage epoch change protocol that efficiently handles storage node churn while maintaining uninterrupted availability during committee transitions. Our system incorporates authenticated data structures to defend against malicious clients and ensures data consistency throughout storage and retrieval processes. Experimental evaluation demonstrates that Walrus achieves practical performance at scale, making it suitable for a wide range of decentralized applications requiring high-integrity, available blob storage with reasonable overhead.
📅 May 30, 2025 | ⏰ 6:00 PM
📍 Athens, Greece
After the talks, join us for a casual networking session with cold beers, wine, and a selection of finger foods.
Whether you're deeply immersed in blockchain development or just curious to learn more, this is a space for everyone.
Come for the talks; stay for the connections.
Looking forward to seeing you in person!