Japanese cryptocurrency exchange Coincheck resumed accepting cryptocurrency withdrawal requests at approximately 08:20 JST on November 8, ending an interruption that lasted more than three days after an external on-chain analytics service experienced an outage. The exchange also restarted processing incoming cryptocurrency deposits, with transfers being credited progressively rather than all at once.
In an update published at 09:10 JST, Coincheck confirmed that both withdrawal requests and incoming deposit processing had resumed. The disruption began at approximately 00:04 JST on November 5, when the external service used to screen cryptocurrency transactions stopped functioning. From the first reported processing delays to the reopening of withdrawals, approximately 80 hours and 16 minutes elapsed.
The service is back open, but the queue is not necessarily gone. Customers whose withdrawal requests were cancelled during the interruption must submit new applications rather than expect their previous instructions to be processed automatically. Some requests had been held for additional review and were to be examined progressively after the service returned.
Coincheck maintained that the incident involved no unauthorized access to its platform and no impact on customer assets. The company attributed the disruption to its external service provider, but did not identify the provider or disclose the technical cause of its failure.
External screening failure disrupted cryptocurrency transfers
The disruption affected two important parts of Coincheck’s cryptocurrency transfer operations. Withdrawal requests could not be accepted normally, while incoming cryptocurrency deposits experienced processing delays before being reflected in customer accounts.
The exchange’s response indicates that its transaction-screening arrangements depend on an external on-chain analytics service. Such systems help cryptocurrency platforms assess wallet addresses and transaction histories for potential exposure to illicit activity before processing transfers.
Coincheck did not disclose whether the service failure affected every supported cryptocurrency equally, how many customers experienced delays or the total value of transactions awaiting processing. It also provided no indication that the underlying blockchain networks themselves had experienced corresponding outages.
The distinction is relevant to understanding what actually stopped. The blockchains could continue processing transactions independently, while Coincheck’s internal procedures for reviewing and accepting transfers remained disrupted because the external screening service was unavailable.
The occurence of several similar interruptions across Japanese cryptocurrency platforms during the same week has also attracted attention. BitTrade, another Japanese exchange, began gradually restoring withdrawals on November 7 after its external screening provider recovered at 15:50 JST. The exchange had suspended all cryptocurrency withdrawals on November 5 at 15:30 JST, producing an interruption of approximately 48 hours and 20 minutes. Its recovery is covered in DaveFinances’ report on BitTrade’s withdrawal restoration after an external screening outage.
Zaif also suspended cryptocurrency deposits and withdrawals across all supported assets on November 5. Its announcement attributed the restriction to preventive maintenance by an external provider operating systems used to verify transfer safety. The stated circumstances were different from Coincheck’s service failure, and neither exchange identified its provider. DaveFinances previously examined Zaif’s exchange-wide cryptocurrency transfer suspension.
Chainalysis outage adds context, but no provider is confirmed
Another development during the same period involved blockchain analytics company Chainalysis, which temporarily took its Know Your Transaction (KYT) interface and API, alongside other address-screening products, offline after detecting abnormal activity affecting its services.
Chainalysis published its November 4 update at 10:30 a.m. Eastern Time, equivalent to 00:30 JST on November 5. Coincheck had reported the beginning of its processing delays at approximately 00:04 JST, around 26 minutes earlier.
Chainalysis subsequently began restoring access to KYT and Address Screening through a phased process. In an update timestamped November 7 at 1:50 p.m. EST, equivalent to 03:50 JST on November 8, the company confirmed that Reactor, KYT and Address Screening were back online with additional security measures. Customers were still being instructed to reconnect through specified procedures.
Coincheck resumed withdrawal requests approximately four and a half hours after that Chainalysis update. The timing is close, and it is hard not to notice, but that is not proof of a link.
Coincheck has not identified the external analytics provider it uses, and it has not confirmed that Chainalysis was involved in its disruption. The two developments must therefore be treated as separate incidents unless further evidence establishes a connection. DaveFinances previously reported on Chainalysis’ shutdown of its cryptocurrency screening products, including the security incident behind the interruption.
The simultaneous timing raises a legitimate question about the concentration of essential transaction-screening services among cryptocurrency platforms. It does not, by itself, establish that a single provider was responsible for the problems reported by multiple exchanges.
Japanese regulatory guidance keeps responsibility with exchanges
Japan’s Financial Services Agency (FSA) has established supervisory expectations addressing the risks cryptocurrency exchanges face when outsourcing operational functions to external contractors.
Its supervisory guidance explicitly states that outsourcing part of an exchange’s business does not remove the exchange’s ultimate responsibility for that work. It also expects providers to maintain arrangements that prevent customers from experiencing unnecessary disruption when an outsourced contractor cannot deliver an agreed service.
The guidance addresses IT contingency planning, monitoring of external service risks and frameworks for minimizing the effects of system failures. It also identifies the possibility of bypassing an affected component as one approach to limiting operational disruption.
For Coincheck, the unanswered operational question is whether alternative screening arrangements were available while its primary provider was unavailable. The exchange has not disclosed whether it considered another analytics provider, an internal verification process or manual transaction reviews that could have allowed at least some transfers to continue.
The FSA’s supervisory guidance for crypto-asset exchange service providers provides the relevant regulatory framework. It does not establish that Coincheck breached any requirement, nor does the incident alone demonstrate a failure of the exchange’s customer-asset safeguards.
The restoration announcement also leaves the scale of the operational backlog unclear. Coincheck has not published the number of cancelled withdrawal applications, the value of delayed deposits or a timetable for completing all outstanding processing. Some customers may not recieve their deposit credits immediately, as the exchange has warned that incoming transfers will be reflected progressively.
For affected customers, the immediate instruction is straightforward: check the transaction history, submit a new withdrawal request if the previous application was cancelled, and allow additional time for pending deposits to be credited.
For exchange operators, this is a fairly invisible dependency until the service stops working. Coincheck has restored its transfer functions, but the incident leaves questions about its contingency arrangements and dependence on external transaction-screening infrastructure. Whether the exchange introduces additional safeguards or provides a more detailed explanation of the failure remains to be seen.
Johan Shamshad is Editor-in-Chief at Dave Finances, covering financial markets, digital assets, trading platforms, brokers, fintech, payments and regulation. Since 2023, he has also worked as an editor at Gulf News, the UAE English-language newspaper published by Al Nisr Publishing LLC. His work focuses on market-moving developments, company disclosures, regulatory changes and trading infrastructure, with an emphasis on primary-source verification and practical context for traders and investors.