CustodyStress
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Part of the CustodyStress archive of observed Bitcoin custody incidents
Exchange SupportExchange custody

Exchange Support — Exchange custody

Cases where exchange support channels were used to attempt recovery of exchange-held Bitcoin. Account verification, support escalation, and identity re-confirmation — the institutional recovery path.

73 cases in this intersection. 20% of determinate cases resulted in a blocked outcome and 12% in access survived. The most common recovery path is exchange support.

10
Blocked
33
Constrained
6
Survived
24
Indeterminate

88% of determinate cases resulted in blocked or constrained access.

73 observed cases
Blocked
10 (14%)
Constrained
33 (45%)
Survived
6 (8%)
Indeterminate
24 (33%)
Zaif Exchange Hack: 5,966 BTC Stolen, User Funds Frozen (September 2018)
Exchange custody
Constrained 2018
On September 14, 2018, the Zaif cryptocurrency exchange operated by Tech Bureau Corp suffered a significant hot wallet breach. Attackers gained unauthorized acc
Blockchain.info Wallet Access Failure: Platform Login System Change (2017)
Exchange custody
Survived 2017
In March 2014, a user created a Blockchain.info-hosted wallet and received a 12-word recovery passphrase as the sole access credential. The user documented the
Blockchain.info Second Password Loss: Vendor Lockout Without Recovery Mechanism
Exchange custody
Indeterminate 2017
In January 2017, forum user ericblogs reported inability to execute transactions on a Blockchain.info hosted wallet after forgetting the account's second passwo
David Vu's Blockchain.info Wallet: Trapped With 2 BTC, Secondary Password Forgotten
Exchange custody
Indeterminate 2017
David Vu discovered a critical access failure in June 2017 when he attempted to withdraw Bitcoin from his Blockchain.info wallet. He retained access to his prim
Kraken Account 2FA Lockout: Support Vanished After ID Verification
Exchange custody
Indeterminate 2017
In September 2017, a Kraken user (z1926) enabled two-factor authentication on their exchange account but encountered a system malfunction during the process. Th
Blockchain.info Wallet Access Blocked by Lost Wallet ID Despite Valid Recovery Phrase
Exchange custody
Indeterminate 2017
In December 2017, a Bitcoin holder discovered that custody of funds deposited in a Blockchain.info wallet created in early 2013 had become inaccessible despite
Blockchain.info 2FA Email Delivery Failure — December 2017 Access Lock
Exchange custody
Constrained 2017
In early December 2017, the user crando discovered they could not access their Blockchain.info hosted wallet after the platform failed to deliver two-factor aut
Bitfinex Account Freeze: 4 BTC Inaccessible for Months During 2017 US Regulatory Scrutiny
Exchange custody
Constrained 2017
In 2017, following regulatory scrutiny from US authorities, Bitfinex began restricting account access for US-based customers. One Reddit user reported that thei
Block.io Custodial Lockout: 2FA Authentication Failure and Support-Dependent Recovery
Exchange custody
Survived 2016
On January 18, 2016, a BitcoinTalk user identified as 'statue' reported being locked out of their Block.io online wallet after entering an incorrect two-factor
Kevin Durant Locked Out of Coinbase Bitcoin Account for 9 Years After 2016 Purchase
Exchange custody
Constrained 2016
Kevin Durant purchased Bitcoin on Coinbase in September 2016 at approximately $650 per coin, following repeated conversations with Golden State Warriors teammat
Vault of Satoshi Exchange Closure: Institutional Custody Dependency and Forced Withdrawal Deadline
Exchange custody
Constrained 2015
Vault of Satoshi, a Canadian cryptocurrency exchange launched in October 2013, announced permanent closure effective February 5, 2015. The platform had differen
Institutional lockout — exchange custody, Australia (2015)
Exchange custody
Constrained 2015
igot, an Australian Bitcoin exchange operated by Remi Fabre under the digital.cc domain, entered a state of operational dysfunction beginning in August 2015. Us
Kraken Exchange DDoS Attack — Users Locked Out During November 2015 Extortion Siege
Exchange custody
Constrained 2015
Kraken, a US-registered cryptocurrency exchange founded in 2011, received an extortion letter in November 2015 demanding Bitcoin payment in exchange for cancell
Institutional lockout — exchange custody, Australia (2015)
Exchange custody
Constrained 2015
In August 2015, the Australian Bitcoin exchange igot ceased all operations and communications, leaving customers unable to access their holdings or funds. Reddi
Bitstamp Exchange Hack — 19,000 BTC Stolen via Employee Phishing, January 2015
Exchange custody
Constrained 2015
On January 4, 2015, Bitstamp discovered that operational hot wallets held approximately 19,000 BTC had been compromised. The Luxembourg-based exchange, a primar
Bitfinex May 2015 Hot Wallet Breach: 1,400 BTC Stolen, Trading Suspended
Exchange custody
Constrained 2015
Bitfinex, a major cryptocurrency exchange operating under Hong Kong incorporation and British Virgin Islands registration, suffered a security breach in May 201
Blockchain.com 2015 Private Key Encoding Bug: 0.48 BTC Permanently Inaccessible
Exchange custody
Indeterminate 2015
In August 2022, a user identified as montythegoat discovered an old Blockchain.com wallet on their Google Drive while cleaning archived files. The wallet had be
CAVIRTEX Closure and Withdrawal Delays: February–March 2015
Exchange custody
Constrained 2015
CAVIRTEX, a Canadian Bitcoin exchange, announced its closure on February 17, 2015, following discovery of a database compromise involving older user information
Cryptsy November 2015: Three Frozen Withdrawals, Unresponsive Support, Hidden Insolvency
Exchange custody
Blocked 2015
In November 2015, a Cryptsy user publicly identified as Bitcointard filed detailed complaints across The Merkle, Reddit, and Bitcointalk forums describing three
Mt. Gox Exchange Collapse: 750,000 Bitcoin Trapped After February 2014 Withdrawal Halt
Exchange custody
Blocked 2014
Mt. Gox, the world's largest Bitcoin exchange at the time, announced a complete halt to all Bitcoin withdrawals on February 7, 2014. The exchange attributed the
Lost Access to 2014 blockchain.info Wallets: Non-Standard Recovery Mnemonics, No Support Response
Exchange custody
Indeterminate 2014
In July 2020, forum user gbola reported locating five recovery mnemonics created circa 2014 when blockchain.info was in its early operations. The user's entire
Blockchain.info Two-Factor Authentication Reset Declined — November 2014
Exchange custody
Constrained 2014
On November 15, 2014, a Blockchain.info user enabled two-factor authentication using Google Authenticator on an Android phone but failed to back up the QR code
0.5 BTC Lost in Blockchain.info Encrypted Wallet (2014)
Exchange custody
Indeterminate 2014
In January 2014, an early Bitcoin adopter purchased BTC on LocalBitcoins and transferred 0.5 BTC to a public address in August of that year. The user recorded o
Mt. Gox Withdrawal Crisis: levino's 347-Page Thread Documents SEPA Delays (April 2013)
Exchange custody
Constrained 2013
On April 18, 2013, BitcoinTalk user levino initiated a withdrawal of Euro proceeds from Mt. Gox, the world's largest Bitcoin exchange at that time. After 14 day
Blockchain.info Hosted Wallet Lockout: Decryption Error and Recovery via Desktop Import
Exchange custody
Indeterminate 2013
In March 2013, a Blockchain.info user ('key2') encountered a critical access failure on the platform's hosted wallet service shortly after their first Bitcoin p
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Terms guide
Survived
Access remained possible under the reported conditions.
Constrained
Access remained possible, but only with delay, dependence, or significant difficulty.
Blocked
Access was not possible under the reported conditions.
Indeterminate
There was not enough information to determine the outcome.
Survivability
The degree to which a custody system maintains the possibility of authorized recovery under stress.
Archive inclusion criteria

This archive documents cases where a legitimate owner, heir, or authorized party encountered barriers accessing or recovering Bitcoin due to a failure in the custody arrangement. The central question for inclusion is: did the custody structure fail a legitimate access or recovery attempt?

A case must satisfy all three of the following to be included:

  1. Legitimate access attempt. The person attempting to access or recover the Bitcoin was the owner, a designated heir, an executor, a legal authority, or another party with a legitimate claim — not a thief, attacker, or unauthorized third party.
  2. Custody structure failure. The failure was caused by a property of the custody arrangement — missing credentials, structural dependencies, documentation gaps, knowledge concentration, legal barriers, or institutional constraints — not market conditions, individual-level fraud or theft, or protocol-level issues. Platform-level failures that block legitimate user access are in scope regardless of their cause.
  3. Documentable outcome or access constraint. The case must have a stated or inferable outcome: access blocked, access constrained, access delayed, or access eventually achieved through a recovery path. Cases with entirely unknown outcomes are included only where the structural failure is documented and the constraint is unambiguous.
  • Owner death or incapacity — Bitcoin held in self-custody that becomes inaccessible to heirs or designated parties because credentials, documentation, or operational knowledge were not transferred
  • Passphrase loss — BIP39 passphrase forgotten or unavailable, blocking access to a funded wallet even where the seed phrase is present
  • Seed phrase or wallet backup unavailable — no independent recovery path existed or the backup was destroyed, lost, or never created
  • Device loss without independent backup — hardware wallet, phone, or computer lost or destroyed with no recovery path outside the device
  • Documentation absent or ambiguous — heirs or executors cannot determine that Bitcoin exists, which wallet holds it, or how to access it
  • Knowledge concentration — only one person knew the procedure, passphrase, or access method; that person is dead, incapacitated, or unreachable
  • Multisig quorum failure — a threshold signature arrangement cannot be completed because signers are unavailable, uncooperative, incapacitated, or have lost their keys
  • Legal authority / access mismatch — a court order, probate ruling, or power of attorney establishes legal entitlement but provides no technical path to access
  • Institutional custody barrier — exchange or platform hacks, insolvency, regulatory seizure, or operational failure that caused a access constraint or failure for legitimate users, whether temporary, prolonged, or permanent. The failure of the custodian to remain available or solvent is itself the in-scope event.
  • Forced relocation or geographic constraint — physical access to a device or location required for recovery is blocked by displacement, border restrictions, or political circumstances
  • Coercion — the holder was compelled under threat to transfer Bitcoin or disclose credentials during an access event
  • Hidden asset discovery — heirs or executors locate a wallet or account but cannot access it due to missing credentials or operational knowledge
  • Market losses, investment losses, yield scheme losses, or Ponzi scheme losses
  • Hacks or theft targeting an individual's personal security (phishing, SIM swap, social engineering, malware) where the custody architecture itself did not fail
  • Unauthorized transfers where the holder's custody system was not the cause of the failure
  • Ordinary transaction mistakes — wrong-address sends, fee errors, mistaken amounts
  • Protocol-level failures — cryptographic vulnerabilities, consensus bugs, firmware integrity failures
  • Deliberate burns or tribute burns
  • Cases where the stated loss is unverifiable and no structural custody failure is described

Cases are drawn from public sources including forum posts, news reporting, court documents, academic research, and direct submissions. Each case is reviewed against the inclusion criteria above before publication. Source material is retained and available on request for documented cases.

The archive is observational and descriptive. It does not attempt to document all Bitcoin custody failures — only those meeting the criteria above with sufficient documentation to describe the structural failure and its outcome.