Former senior Department of Justice official and seasoned cryptocurrency prosecutor Eun Young Choi discussed the growing problem of North Korean-affiliated cryptocurrency theft and the challenges law enforcement faces in tracing and recovering stolen digital assets in an interview with Yahoo Finance, drawing on her extensive experience leading federal cryptocurrency enforcement efforts.

Key points from the interview

• North Korean actors are major targets of U.S. enforcement attention. Choi highlighted concern about North Korean state-affiliated cyber actors exploiting digital assets to evade sanctions and raise funds for prohibited programs.
• Blockchain pseudonymity complicates attribution. She explained that blockchains provide transaction records but not straightforward identities, so linking an address to real-world actors requires combining on-chain analysis with traditional investigative methods.
• Cross-border, fragmented infrastructure creates enforcement gaps. Choi noted that mixers, foreign-registered platforms, and distributed personnel across jurisdictions make it difficult to gather evidence or compel cooperation.
• Coordination among agencies is essential. Drawing on her work creating and leading DOJ crypto enforcement units, she stressed the need for sustained interagency and international cooperation to disrupt and deter state-linked thefts.

Background: Choi’s credentials and why her perspective matters

Eun Young Choi served in senior roles at the Department of Justice where she helped build the federal government’s cryptocurrency enforcement capabilities, including work with the National Cryptocurrency Enforcement Team and the National Security Cyber Section; those positions gave her direct experience with investigations involving digital asset theft, nation-state cyber activity, and sanctions evasion.

How North Korean-linked groups exploit crypto

Choi and other experts say the general pattern involves sophisticated cyber intrusions into crypto platforms, decentralized finance (DeFi) protocols, and cross-chain bridges, followed by laundering the proceeds through services such as mixers, chain-hopping, and use of third-party platforms to obscure origin and ownership. These tactics are used to convert stolen tokens into usable value while attempting to frustrate tracking and recovery efforts.

Investigative and legal challenges

Choi emphasized several practical obstacles investigators face when responding to cryptocurrency thefts tied to sanctioned states:

• Pseudonymous ledgers. While blockchains record transactions, they do not directly reveal the humans behind addresses, requiring additional technical and human intelligence to attribute activity.
• Jurisdictional complexity. Platforms, personnel, and data may be located in different countries, complicating legal process and operational coordination.
• Rapid movement of funds. Cryptocurrency transactions can be executed quickly and across chains, creating narrow windows for seizure or law enforcement action.

What enforcement looks like in practice

Choi’s remarks reflect the DOJ’s broader approach that combines:

• Forensic blockchain analysis to trace flows of stolen funds;
• Interagency collaboration — including federal law enforcement, financial regulators, and intelligence partners — to assemble a legal and operational case;
• International cooperation and mutual legal assistance to pursue actors and compel evidence located overseas.

Policy and industry implications

Experts who follow Choi’s work argue that tackling state-linked crypto theft requires both stronger technical defenses within the crypto industry and clearer regulatory channels for cross-border cooperation. Industry measures such as improved know-your-customer (KYC) controls on centralized platforms, responsible smart-contract design, and better on- and off-ramps monitoring can make it harder for malicious actors to monetize thefts, while law enforcement tools and partnerships can improve recovery and accountability.

Reaction and next steps

Choi’s comments reiterate long-standing concerns raised by U.S. authorities: cryptocurrency offers both forensic transparency and practical concealment for illicit actors, and nation-state groups such as those linked to North Korea represent a national security challenge because of their apparent use of cybertheft to fund prohibited programs. Observers say continued investment in technical capabilities, legal frameworks, and international cooperation will be necessary to reduce the scale and impact of these crimes.