Cavirtex Exchange Shutdown and Withdrawal Lockdown (March 2015)
IndeterminateCustodial platform became inaccessible — whether funds were recovered is not documented.
Cavirtex, a Canadian Bitcoin and Litecoin exchange founded in late 2011, discovered a compromise of an older database version on February 15, 2015. The breach exposed 2FA secrets and hashed passwords, though the exchange stated that identification documents and production systems remained unaffected. In response to the security incident, Cavirtex announced an orderly wind-down and halted trading on March 20, 2015.
Three days later, on March 25, 2015, Cavirtex disabled all Bitcoin and Litecoin withdrawals. The exchange committed to processing only those withdrawal requests received before the cutoff date and promised to communicate with account holders retaining balances afterward. Cavirtex maintained that it was solvent, held 100% reserves, and had never lost customer funds. The production environment, the exchange asserted, had not been compromised.
However, the response to the credential breach created a critical friction point. Cavirtex required users to update passwords, clear browser cookies, and—critically—re-enter their Bitcoin and Litecoin withdrawal addresses. These address fields had been cleared for all users as a security measure. This administrative requirement imposed a hard deadline: users had a limited window to authenticate, confirm account access, and specify a destination address before automated processing commenced.
Users unable to meet this deadline faced prolonged delays or effective permanent inaccessibility to their funds. Those who had lost access to email accounts, 2FA devices, or secondary authentication codes could not complete re-verification in time, creating a de facto custody barrier despite the exchange's stated solvency and intent to return all user funds. The incident exemplifies a recurrent failure mode in institutional custody: operational security responses to breaches, even when adopted by solvent institutions, can create access denial for subsets of users unable to navigate administrative requirements under compressed timelines.
| Stress condition | Vendor lockout |
| Custody system | Exchange custody |
| Outcome | Indeterminate |
| Documentation | Partial |
Why custodial Bitcoin fails differently than self-custody
Exchange custody transfers the custody problem from the holder to the institution. The holder no longer needs to manage seed phrases, maintain hardware, or understand cryptographic concepts. They need only to maintain their account. This simplicity has a cost: the holder no longer controls the private keys. Access depends entirely on the continued operational, financial, and regulatory health of the exchange.
Cases in this archive show that exchange failures cluster around specific event types: bankruptcy and insolvency, regulatory seizure, geographic sanctions, and account-level access failures (lost 2FA, forgotten email credentials). Each event type has a different recovery path and a different timeline. Bankruptcy proceedings typically take 6-24 months and produce partial recovery. Regulatory seizure timelines depend on legal process. Account access failures may be resolvable through platform support or may not.
The distinguishing feature of vendor lockout cases is that recovery — when it occurs — happens through processes the holder did not design and cannot control. They become claimants in a process rather than holders of an asset.
The primary protection against vendor lockout is not using a vendor for custody beyond what is needed operationally. Holdings intended to be stored long-term are most exposed to institutional risk. Exchange custody is well-suited for active trading and conversion; it is poorly suited for long-term storage of significant value. Moving Bitcoin off exchange into self-custody eliminates platform dependency at the cost of taking on personal custody responsibility.
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