比特幣匿名聲明經受考驗

研究人員開發了新技術，透過 1,600 萬筆交易和 1,200 萬個線上來源的公鑰來追蹤比特幣的流動。

The blockchain is a series of transactions, each one referencing the previous transaction, to form a chain. Transactions are grouped into blocks, with each block referencing the previous one and serving as a timestamp that validates the transactions it contains. Blocks are then formed into chains and made publicly available to every user within the system.

區塊鏈是一系列交易，每筆交易都引用前一筆交易，形成一條鏈。交易被分組為區塊，每個區塊引用前一個區塊並充當驗證其包含的交易的時間戳。然後，區塊被形成鏈並公開提供給系統內的每個使用者。

Meiklejohn and her fellow researchers developed a new clustering heuristic, or systematic method of associating data, to comb through the massive database of blockchain transactions and link transactions. Their algorithms put Bitcoin’s anonymity claims to the test.

Meiklejohn 和她的研究人員同事開發了一種新的聚類啟發式方法，即關聯資料的系統方法，以梳理區塊鏈交易和連結交易的海量資料庫。他們的演算法對比特幣的匿名性進行了考驗。

“Our work seeks to better understand the traceability of Bitcoin flows and, through this understanding, explore the evolution of how Bitcoin has been used over time,” they said.

他們表示：“我們的工作旨在更好地了解比特幣流動的可追溯性，並通過這種理解，探索比特幣隨著時間的推移如何使用的演變。”

The team built on past efforts to cluster public keys, or Bitcoin user addresses, based on evidence of shared spending authority. Once they could positively identify one public key, they could link an entire cluster of transactions containing that same public key.

該團隊以過去的努力為基礎，根據共享支出權限的證據，對公鑰或比特幣用戶地址進行叢集。一旦他們能夠肯定地識別一個公鑰，他們就可以連結包含相同公鑰的整個交易群集。

They also employed a re-identification attack. Essentially, they opened accounts and made purchases from a broad range of Bitcoin merchants and service providers. Since they were at one end of the transaction, they could positively identify the other end as the service provider.

他們還採用了重新識別攻擊。本質上，他們從眾多比特幣商家和服務提供者開設帳戶並進行購買。由於他們位於交易的一端，因此他們可以肯定地將另一端識別為服務提供者。

Employing this meticulous methodology, Meiklejohn was able to follow the money, or Bitcoins, through a seemingly impenetrable web of 16 million transactions and 12 million public keys to their online sources. Her novel tracing technique eventually led law enforcement to user addresses of criminals. With a subpoena in hand, officials could put a name to the crime. Today, variants of these algorithms are in daily use in both government enforcement and private sector compliance roles, supported by a range of crypto tracing companies including Chainalysis, Elliptic, TRM Labs, and CipherTrace (now part of Mastercard).

運用這種細緻的方法，Meiklejohn 能夠透過一個看似堅不可摧的網路來追蹤資金或比特幣，該網路由 1,600 萬筆交易和 1,200 萬個線上來源的公鑰組成。她新穎的追蹤技術最終引導執法部門找到了犯罪者的使用者地址。有了傳票，官員們就可以為犯罪行為定名。如今，這些演算法的變體在政府執法和私營部門合規角色中日常使用，並得到一系列加密追蹤公司的支持，包括 Chainaanalysis、Elliptic、TRM Labs 和 CipherTrace（現已成為 Mastercard 的一部分）。

Today, Meiklejohn is a professor in cryptography and security at University College London (UCL) and a staff research scientist at Google.

如今，Meiklejohn 是倫敦大學學院 (UCL) 的密碼學和安全學教授，也是 Google 的研究員。

Levchenko is an associate professor in electrical and computer engineering at the University of Illinois; McCoy is a professor at New York University Tandon School of Engineering; Jordan is the founder and CEO of anti-drone startup, SkySafe; and Pomarole is an investor and consultant for Brazilian tech startups.

Levchenko 是伊利諾大學電機與電腦工程系副教授；麥考伊是紐約大學坦登工程學院教授； Jordan 是反無人機新創公司 SkySafe 的創辦人兼執行長； Pomarole 是巴西科技新創公司的投資者和顧問。

IMC 2024 is the 24th in a series of flagship conferences sponsored by ACM SIGCOMM, a professional forum for the discussion of topics in the field of communications and computer networks. This three-day event focuses on Internet measurement and analysis in areas such as technical design and engineering, regulation and operations, and the social implications of computer networking.

IMC 2024 是 ACM SIGCOMM 主辦的一系列旗艦會議中的第 24 屆會議，ACM SIGCOMM 是一個討論通訊和電腦網路領域主題的專業論壇。這個為期三天的活動重點關注技術設計和工程、監管和運營以及電腦網路的社會影響等領域的互聯網測量和分析。

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