DAP-CBR: enhancing Bitcoin block propagation efficiency using dynamic compact block relay’s prefilling of transactions

The Journal of Supercomputing (2025) 81:77 https://doi.org/10.1007/s11227-024-06468-0 DAP‑CBR: enhancing Bitcoin block propagation efficiency using dynamic compact block relay’s prefilling of transactions Zi Hau Chin1,2 · Vishnu Monn Baskaran1 · Chee Keong Tan1 · Ian K. T. Tan2 · Timothy T. V. Yap2 Accepted: 5 October 2024 © The Author(s) 2024 Abstract This study examines the potential of BIP-152’s Compact Block Relay (CBR) to enhance the Bitcoin network. This work explores the block propagation efficiency through dynamic prefilling of transactions. In addition, an enhanced CBR model is proposed to reduce superfluous transaction requests, thus improving the block distribution process. The analysis considers the impact of the dynamically prefilled transactions on Bitcoin network scalability, comparing the advantages and disadvantages of this approach. We also conduct a comparative study of fixed-size and dynamically sized prefilled transactions to highlight the importance of adapting to network demands. Prefilling a fixed number of transactions without considering demand can cause inefficiencies and strain the network with unnecessary bandwidth use. Indiscriminate prefilling exacerbates these issues by inflating data packets unnecessarily, increasing latency and reducing network responsiveness. Our research indicates that the proposed solution can significantly reduce the number of round-trips between network nodes by an average of 29.77% and block reconstruction latency by 39.10% when compared with the CBR. Keywords Bitcoin · Blockchain · Compact block relay (CBR) · Round-trip · Block propagation · Delay 1 Introduction Blockchain technology, known for its decentralized and immutable nature, has revolutionized numerous industries. Cryptocurrencies, a critical blockchain application, operate without centralized control, relying on market forces for valuation. Despite the groundbreaking impact of cryptocurrencies such as Bitcoin (2008) V. M. Baskaran, C. K. Tan, I. K. T. Tan, T. T. V. Yap have contributed equally to this work. Extended author information available on the last page of the article Vol.:(0123456789) 77 Page 2 of 33 Z. H. Chin et al. and Ethereum (2015), which revolutionized smart contracts, scalability remains a significant challenge. The performance of blockchain platforms is determined by factors such as transaction throughput, confirmation latency, and block propagation efficiency [1]. As the user base grows, these limitations become increasingly apparent, requiring solutions to improve performance and overall user experience [2]. Blockchain technology seeks to achieve the following three key characteristics: [3]: 1. Decentralization the distribution of network control to prevent single points of failure or authority. 2. Scalability the ability of the blockchain to process a growing volume of transactions. 3. Security the robustness of the blockchain against various attacks and its ability to prevent fraud, such as double-spending. However, achieving all three simultaneously presents a significant challenge, aptly captured by the term “Blockchain Trilemma", which describes this inherent trade-off. Blockchains face a trade-off between scalability and efficiency. In addition to ensuring security, they strive to handle increasing transaction volumes without compromising performance [4]. A key factor affecting efficiency is block relay latency, the time taken for a newly mined block to propagate through the network [5, 6]. Efficient block propagation allows for faster propagation of freshly mined blocks across the network. However, traditional blockchain protocols can experience communication bottlenecks, leading to block propagation inefficiencies [7]. One notable development is Compact block relay (CBR), or Bitcoin improvement proposal (BIP) 152 [8]. It was introduced on April 27, 2016, and has since played a critical role in the ongoing discourse on Bitcoin’s network performance enhancements. Beyond its aim to reduce bandwidth consumption for block propagation within the Bitcoin network, CBR also presents the potential mitigates [9]. Interestingly, the original CBR proposal considered prefilling compact blocks with assumed missing transactions. However, this functionality was ultimately excluded from the final implementation, leaving it an open area for further research. Building upon existing research, we focus on a specific source of delay in CBR as identified by [10]. This delay occurs during the reconstruction of a full block, particularly when missing transactions are requested. To address this issue, the authors proposed to utilize a previously unimplemented aspect of the CBR’s proposal: prefilling a fixed number of transactions. Their approach involves including a predefined set of 30 complete transactions during compact block creation. Furthermore, they examined criteria for selecting prefilled transactions, such as transaction fee, size, and mempool entry time, to optimize the method’s overall efficiency. Prefilling a set number of transactions during block propagation can reduce delay but has efficiency limitations. First of all, nodes that only require some prefilled transactions would be burdened with wasting bandwidth by downloading DAP‑CBR: enhancing Bitcoin block propagation efficiency… Page 3 of 33 77 unnecessary data [11]. Secondly, the inflexibility of a fixed prefilling scheme hinders its ability to adapt to dynamic network conditions. During periods of high transaction volume, the prefilled amount might be insufficient to cover all missing requests. This could lead to additional request messages, negating some benefits. On the other hand, prefilling a fixed amount could be excessive during low-traffic periods, creating unnecessary network overhead and bandwidth wastage. This study delves into the concept of CBR and emphasizes the potential of dynamically prefilling transactions based on recent request history. We examine the technical intricacies of CBR operations, highlighting its limitations and opportunities for improvement. We introduce the demand-aware prefilling CBR (DAP-CBR) scheme, aimed at reducing round-trip communication overhead when requesting missing transactions during compact block reconstruction. By minimizing these round-trips, DAP-CBR has the potential to decrease block relay latency significantly [12]. Furthermore, we investigate the impact of incorporating dynamically prefilled transactions into compact blocks on the scalability of the Bitcoin network. This analysis involves a comparative evaluation of fixed-size versus dynamic prefilling strategies, providing valuable insights into potential improvements for blockchain network efficiency and scalability. By examining this approach, we aim to contribute to blockchain optimization efforts, paving the way for more robust and scalable applications. 2 Compact block relay Compact Block Relay (CBR) emerges as a potential solution to address inefficiencies (...truncated)