论文标题
用于编码的默克尔树的集中停止设置设计：改善区块链系统中数据可用性攻击的安全性
Concentrated Stopping Set Design for Coded Merkle Tree: Improving Security Against Data Availability Attacks in Blockchain Systems
论文作者
论文摘要
在某些区块链系统中，轻节点是仅下载块的一小部分的客户端。光节点容易受到数据可用性（DA）攻击的影响，其中恶意节点隐藏了块中块的无效部分。最近，Yu等人提出了基于称为编码的Merkle树（CMT）的擦除代码的技术。这样可以使光节点以高概率检测DA攻击。 CMT是使用LDPC代码进行快速解码构建的，但如果恶意节点隐藏了代码的小停止集，则无法检测到DA攻击。为了应对这一目标，Yu等人。使用良好的技术来设计具有高最小停止设置尺寸的随机LDPC代码。尽管有效，但这些代码不一定对于此应用程序是最佳选择。在本文中，我们演示了更专业的LDPC代码设计，以提高针对DA攻击的安全性。我们通过提供确定性的LDPC代码构建来实现这一目标，该构建的重点是将停止集集中在一小部分可变节点上，而不仅仅是消除停止集。我们通过将渐进边缘生长算法修改为一种称为熵受限的PEG（EC-PEG）算法的技术来设计这些代码。这种新方法证明了检测DA攻击并允许短长度良好的代码的概率更高。
In certain blockchain systems, light nodes are clients that download only a small portion of the block. Light nodes are vulnerable to data availability (DA) attacks where a malicious node hides an invalid portion of the block from the light nodes. Recently, a technique based on erasure codes called Coded Merkle Tree (CMT) was proposed by Yu et al. that enables light nodes to detect a DA attack with high probability. The CMT is constructed using LDPC codes for fast decoding but can fail to detect a DA attack if a malicious node hides a small stopping set of the code. To combat this, Yu et al. used well-studied techniques to design random LDPC codes with high minimum stopping set size. Although effective, these codes are not necessarily optimal for this application. In this paper, we demonstrate a more specialized LDPC code design to improve the security against DA attacks. We achieve this goal by providing a deterministic LDPC code construction that focuses on concentrating stopping sets to a small group of variable nodes rather than only eliminating stopping sets. We design these codes by modifying the Progressive Edge Growth algorithm into a technique called the entropy-constrained PEG (EC-PEG) algorithm. This new method demonstrates a higher probability of detecting DA attacks and allows for good codes at short lengths.
