【Author】
Biryukov, Alex; Khovratovich, Dmitry; Pustogarov, Ivan
【Source】CCS'14: PROCEEDINGS OF THE 21ST ACM CONFERENCE ON COMPUTER AND COMMUNICATIONS SECURITY
【Abstract】Bitcoin is a digital currency which relies on a distributed set of miners to mint coins and on a peer-to-peer network to broadcast transactions. The identities of Bitcoin users are hidden behind pseudonyms (public keys) which are recommended to be changed frequently in order to increase transaction unlinkability. We present an efficient method to deanonymize Bitcoin users, which allows to link user pseudonyms to the IP addresses where the transactions are generated. Our techniques work for the most common and the most challenging scenario when users are behind NATs or firewalls of their ISPs. They allow to link transactions of a user behind a NAT and to distinguish connections and transactions of different users behind the same NAT. We also show that a natural countermeasure of using Tor or other anonymity services can be cut-off by abusing anti-DoS countermeasures of the Bitcoin network. Our attacks require only a few machines and have been experimentally verified. The estimated success rate is between 11% and 60% depending on how stealthy an attacker wants to be. We propose several countermeasures to mitigate these new attacks.
【Keywords】Bitcoin; Anonymity; P2P; Tor
【摘要】比特币是一种数字货币，它依赖于一组分布式的矿工来铸造货币，并通过点对点网络来广播交易。比特币用户的身份隐藏在假名(公钥)后面，建议频繁更改这些假名，以增加交易的不可链接性。我们提出了一种对比特币用户去匿名化的有效方法，它允许将用户假名链接到产生交易的IP地址。当用户在nat或isp的防火墙后面时，我们的技术适用于最常见和最具挑战性的场景。它们允许将事务的用户在NAT和区分不同用户的连接和事务,同一个NAT的后面。我们还表明,自然使用Tor或其他匿名服务的对策可以被滥用截止anti-DoS比特币网络的对策。我们的攻击只需要几台机器，并且已经经过实验验证。据估计，成功率在11%到60%之间，这取决于攻击者想要隐身的程度。我们提出了几种对策来减轻这些新的攻击。
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