The L1 Weekly Report is published every Friday, focusing on the development of Layer 1 blockchains. If you have any suggestions, feel free to contact [email protected].

Bitcoin

• LND’s Deadline-Aware Budget Sweeper
  • LND v0.18.0 introduced a deadline-aware budget sweeper that dynamically adjusts transaction fees using HTLC-specific deadlines and budgets (e.g., 50% of HTLC value) to prioritize urgent on-chain claims. Unlike strategies relying on external fee estimators or exponential bumping, this approach calculates fee curves based on remaining time and allocated budgets, improving defense against replacement cycling and pinning attacks. It fixes critical bugs in prior versions, such as inconsistent fee bumping and invalid transaction batching, while reducing dependency on unreliable fee rate predictions. By aligning fee spending with HTLC values and deadlines, the system ensures attackers face prohibitively high costs (e.g., 20–200x HTLC value) to exploit vulnerabilities. Though offering stronger security, developers caution against major code overhauls in on-chain logic due to inherent risks.
• CTV+CSFS: Can we reach consensus on a first step towards covenants?
  • The discussion explores activating CTV and CSFS opcodes as a cautious first step toward Bitcoin covenants, aiming to enhance second-layer protocols like Lightning and Ark by reducing pre-signed transaction complexity. Proponents argue these opcodes are well-tested, minimally risky, and lay groundwork for future upgrades, while critics question their immediate utility, citing limited real-world demand and potential technical limitations compared to alternatives like TXHASH. Key concerns include insufficient use-case validation and the broader implications of covenant-enabled features on network incentives. The debate highlights tensions between incremental protocol improvements and maintaining Bitcoin’s security-first ethos.
• An Exposition of Pathfinding Strategies Within Lightning Network Clients
  • This study analyzes pathfinding strategies across major Lightning Network clients (LND, CLN, LDK, Eclair), revealing how their distinct weight functions balancing fees and success probabilities impact performance. While all use modified shortest-path algorithms, LND’s multiplicative penalty for low-probability paths risks suboptimal routing compared to CLN/LDK/Eclair’s logarithmic approach. Simulations show tradeoffs: LND variants achieve higher success rates (76% uniform/63% bimodal) but higher fees, while Eclair3 offers lowest fees and CLN minimizes latency. The findings highlight inherent limitations in current Dijkstra-based approaches and advocate for advanced algorithms to better optimize payment reliability, cost, and network efficiency.

Ethereum

• Separation Gap, Trusted Advantage, and APS
  • The article explores the “separation gap” in Ethereum’s consensus, analyzing how timing disparities between protocol phases create vulnerabilities. It discusses “trusted advantage” scenarios where participants exploit assumptions for gains, and evaluates APS (Attestation Propagation Strategies) to mitigate risks. The analysis emphasizes balancing liveness, security, and decentralization while addressing trust dependencies. Proposed solutions aim to refine protocol parameters and attestation propagation for robustness against adversarial edge cases.
• Safety Analysis of the Beacon Chain
  • This analysis evaluates Ethereum’s Beacon Chain safety by examining source/target attestation correctness from Genesis (2020) to 2025. While 99% of epochs maintained >90% correctness, 33 critical safety drops below 66% occurred, notably in May 2023. Fluctuations correlated with hard fork transitions, though resilience improved over time. The study highlights vulnerabilities requiring ≥33% validator failures to disrupt finality, emphasizing the chain’s robust-but-imperfect safety mechanisms.
• Doubling the blob count with Gossipsub v2.0
  • Gossipsub v2.0 introduces a “lazy-pull” mechanism using new control messages (IANNOUNCE/INEED) to reduce network amplification by broadcasting message IDs first and retrieving content on-demand, cutting duplicates significantly. Simulations show this approach doubles blob propagation capacity (e.g., 32 vs. 16 messages in 4 seconds) by optimizing bandwidth usage under congestion. While latency increases slightly, parameter tuning (e.g., D_announce) balances speed and efficiency. Challenges remain in setting timeouts and handling adversarial peers, but the design offers scalable improvements for large-message networks like Ethereum.
• Economic Censorship Games in Fraud Proofs
  • This paper analyzes economic censorship attacks in optimistic rollups, where adversaries bribe Ethereum block proposers to censor fraud proof transactions during the challenge period. It models strategic interactions between attackers, defenders, and proposers across three game variants, deriving budget thresholds required for security based on challenge duration, gas costs, and proposer behavior. Practical parameterization using Ethereum’s 50,000-block challenge window and BoLD rollup data shows defenders need 5.6M−12M budgets to resist attacks, reduced further by special censorship-resistant rounds (k=60-72) or multi-proposer systems (m=20). The results demonstrate how protocol design adjustments like inclusion lists and default proposers substantially lower economic security barriers.
• MEV: Scalable fair-ordered DAG Mempool (DAGPool)
  • DAGPool introduces a DAG-based mempool protocol leveraging gossip-DAG structures to address Ethereum’s scalability, MEV exploitation, and censorship challenges. By integrating a γ-batch order fairness model (adapted from Themis) with leader-based consensus, it ensures transaction fairness through ranked voting while enabling high-throughput via asynchronous DAG propagation. The protocol resists censorship by preventing leaders from omitting transactions in their truncated processing cones and offers compatibility with Ethereum’s architecture. However, challenges like scaling to large validator sets, mitigating flooding attacks, and implementation complexity remain critical considerations for adoption.
• The Target Demand Paradox in the Blob Fee Market: An Analysis of EIP-4844 & EIP-7961
  • The article analyzes Ethereum’s blob fee market under EIP-4844, revealing a paradox where blob prices remain near minimum levels despite average consumption approaching the 3-blocks-per-target threshold, due to demand volatility and asymmetric fee mechanisms. Simulations show equilibrium requires sustained demand exceeding 3.13-3.2 blobs/block, creating instability when target values fall outside this “effective demand” range. Proposed EIP-7961’s parameter changes (6 target/9 max blobs) risk worsening this paradox by raising equilibrium thresholds beyond practical usage. Solutions include symmetric fee adjustment ranges, minimum price hikes, or Dutch auction-style initial pricing to accelerate fair price discovery while maintaining Ethereum’s rollup-centric roadmap.