Cryptocurrency is a novel exploration of a form of currency that proposes a decentralized electronic payment scheme based on blockchain technology and cryptographic theory. While cryptocurrency has the security characteristics of being distributed and tamper-proof, increasing market demand has led to a rise in malicious transactions and attacks, thereby exposing cryptocurrency to vulnerabilities, privacy issues, and security threats. Particularly concerning are the emerging types of attacks and threats, which have made securing cryptocurrency increasingly urgent. Therefore, this paper classifies existing cryptocurrency security threats and attacks into five fundamental categories based on the blockchain infrastructure and analyzes in detail the vulnerability principles exploited by each type of threat and attack. Additionally, the paper examines the attackers' logic and methods and successfully reproduces the vulnerabilities. Furthermore, the author summarizes the existing detection and defense solutions and evaluates them, all of which provide important references for ensuring the security of cryptocurrency. Finally, the paper discusses the future development trends of cryptocurrency, as well as the public challenges it may face.

翻译：加密货币是一种新型货币形式的探索，它提出了一种基于区块链技术和密码学理论的去中心化电子支付方案。虽然加密货币具有分布式和防篡改的安全特性，但日益增长的市场需求导致了恶意交易和攻击的增加，从而使加密货币面临漏洞、隐私问题和安全威胁。尤其值得关注的是新兴的攻击类型和威胁，这使得保障加密货币的安全性变得日益紧迫。因此，本文根据区块链基础设施将现有的加密货币安全威胁和攻击分为五大基本类别，并详细分析了每类威胁和攻击所利用的漏洞原理。此外，本文还研究了攻击者的逻辑和方法，并成功复现了这些漏洞。进一步地，作者总结了现有的检测与防御解决方案并对其进行了评估，这些工作为确保加密货币的安全性提供了重要参考。最后，本文探讨了加密货币的未来发展趋势以及可能面临的公共挑战。