Israel extradited Alexander Block, an Israeli-Russian citizen accused of stealing $2.8 million in digital assets through the Nomad blockchain bridge, to the United States on Oct. 29 after the country’s Supreme Court rejected his final appeals.
U.S. prosecutors allege Block exploited a vulnerability in Nomad’s automated system to withdraw tokens without depositing corresponding backing assets. He allegedly converted the stolen tokens into other cryptocurrencies and moved them between digital wallets to conceal their origin.
Federal charges and extradition request
According to the Israeli Supreme Court’s ruling, U.S. authorities indicted Block in the Northern District of California in August 2023 on eight counts involving computer offenses, transferring stolen property and money laundering. The U.S. formally requested his extradition in December 2024.
Nomad operated as a cross-chain bridge that let users transfer digital assets between blockchain networks. In normal operation, users locked assets on one blockchain before receiving corresponding tokens on another.
Block was arrested at Israel’s Ben-Gurion Airport in May 2025 while preparing to board a flight to Russia. Before his arrest, he had changed his surname from Gurevich to Block and obtained a passport under his new name.
Court rejects appeals
The Jerusalem District Court approved Block’s extradition in July 2025, but he appealed, challenging the legal basis of the charges and the sufficiency of the evidence. His defense argued the transactions were executed through functions built into Nomad’s automated system and therefore did not constitute unlawful computer intrusion under Israeli law.
Block also disputed the money laundering allegations, arguing that the public visibility of blockchain transactions undermined claims that he attempted to conceal the movement of funds.
Israel’s Supreme Court rejected those arguments, ruling that exploiting a programming vulnerability could constitute unlawful computer intrusion even if the software technically allowed the transactions to proceed.
The court also determined that the transparent nature of blockchain transactions does not preclude money laundering. Although transfers are publicly recorded, the identities of individuals controlling the wallets are not always clear, allowing users to obscure the source or ownership of digital assets.
Following the failed appeals, Israeli authorities coordinated Block’s transfer to the U.S. early on Oct. 29. The State Attorney’s Office said the extradition was carried out through cooperation between its International Department, the Israel Police’s operational coordination division and Interpol units.
