CustodyStress
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Part of the CustodyStress archive of observed Bitcoin custody incidents
Cycle 3Vendor lockout

Halving Cycle 3 (2017–2020) — Vendor lockout

Exchange failures from Halving Cycle 3 (2017–2020). The post-2017 bull cycle produced a surge of new exchange users, followed by a wave of closures in the 2018–2019 bear market. QuadrigaCX — where the founder died holding sole custody — is the defining institutional failure of this cycle.

54 cases in this intersection. 59% of determinate cases resulted in a blocked outcome and 3% in access survived. The most common recovery path is exchange support.

22
Blocked
14
Constrained
1
Survived
17
Indeterminate

97% of determinate cases resulted in blocked or constrained access.

54 observed cases
Blocked
22 (41%)
Constrained
14 (26%)
Survived
1 (2%)
Indeterminate
17 (31%)
Blockchain.com Wallet Zero Balance: Seed Phrase and Backup File Present, Funds Inaccessible
Exchange custody
Indeterminate 2018
In late 2015, the user rory4ever created a Bitcoin wallet using Blockchain.info (the platform's name before rebranding to Blockchain.com) and deposited approxim
BitGrail Exchange Collapse: 17 Million NANO Stolen, 230,000 Users Frozen
Exchange custody
Blocked 2018
BitGrail, an Italian cryptocurrency exchange, announced on February 8, 2018 that approximately 17 million NANO tokens—valued at roughly $170 million at the time
Bitfinex Fiat Withdrawal Freeze: Crypto Capital Processing Delays October–November 2018
Exchange custody
Constrained 2018
Bitfinex paused fiat deposits in October 2018 and announced implementation of a new deposit system. The exchange had been routing USD withdrawals through Crypto
Blockchain.info Wallet Access Lost After Signup—Recovery Phrase Known
Exchange custody
Indeterminate 2018
On March 16, 2018, a user with the handle ilovegambling created a new Blockchain.info wallet to receive Bitcoin from an online betting platform. The user record
QuadrigaCX Exchange Collapse: C$100,000 Withdrawal Never Processed
Exchange custody
Blocked 2018
Eric Z., a QuadrigaCX customer, deposited C$5,000 into the Canadian cryptocurrency exchange around 2014 and grew his position to approximately C$125,000 through
Xitong Zou: QuadrigaCX Creditor During Exchange Collapse and Fraud
Exchange custody
Blocked 2018
Xitong Zou was a customer of QuadrigaCX, a Canadian cryptocurrency exchange that collapsed in late 2018. Like thousands of other users, Zou had cryptocurrency h
Cointed GmbH Exchange Collapse: Austria, 2018 — Customer Funds Disappeared
Exchange custody
Blocked 2018
Cointed GmbH, founded in 2016 in Kufstein, Austria, operated as a regional cryptocurrency powerhouse: a custodial exchange, mining operation, and operator of on
Coincheck Exchange Hack: 523 Million NEM Stolen, User Withdrawals Frozen
Exchange custody
Constrained 2018
On January 26, 2018, Coincheck, a Tokyo-based cryptocurrency exchange, discovered that attackers had stolen approximately 523 million NEM tokens valued at $530
Coinrail Exchange Hack — $40 Million Altcoin Loss, Partial Recovery
Exchange custody
Constrained 2018
On June 10, 2018, Coinrail, a South Korean cryptocurrency exchange, publicly confirmed a security breach affecting its hot wallet infrastructure. Attackers gain
MapleChange Exit Scam: 919 Bitcoin Lost, CEO Identified as Glad Poenaru
Exchange custody
Blocked 2018
MapleChange, a small Canadian cryptocurrency exchange, announced on October 28, 2018 that it had suffered a catastrophic hack. According to the exchange's Twitt
Bithumb $31 Million Hack — June 2018 Withdrawal Suspension
Exchange custody
Constrained 2018
Bithumb, one of South Korea's dominant cryptocurrency exchanges handling billions in daily trading volume, discovered a security breach on June 19, 2018. Intern
Elvis Cavalic and QuadrigaCX: C$15,000 Withdrawal Lost to Exchange Collapse
Exchange custody
Blocked 2018
Elvis Cavalic of Calgary, Alberta was an active QuadrigaCX customer who had accumulated cryptocurrency holdings through trading on the platform. In October 2018
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
Xapo Mobile 2FA Lockout: User Without Smartphone Denied Account Access
Exchange custody
Blocked 2017
In August 2017, Xapo transitioned its hosted wallet platform to mandatory two-factor authentication via mobile application. A user (songdove) without a smartpho
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
7 BTC Lost After Address Disappearance on Blockchain.info Web Wallet
Exchange custody
Indeterminate 2017
In August 2017, a BitcoinTalk forum user reported a significant loss involving approximately 7 BTC stored on Blockchain.info. The user had migrated from Bitcoin
Yapizon Exchange Hack (April 2017): 3,831 BTC Stolen, Socialised Loss Model Applied to All Users
Exchange custody
Blocked 2017
On April 22, 2017, Yapizon, a South Korean cryptocurrency exchange, suffered a security breach resulting in the theft of 3,831 BTC—approximately 37% of the exch
Youbit Exchange Bankruptcy: Second Hack Triggers 75% Fund Recovery Limit
Exchange custody
Constrained 2017
Youbit, operated by South Korean firm Yapian, experienced two significant security breaches during 2017. The first attack in April 2017 compromised approximatel
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
Institutional lockout — exchange custody (2017)
Exchange custody
Indeterminate 2017
Between 2014 and 2015, the user created cryptocurrency accounts on blockchain.info and retained the mnemonic seed phrases. By December 2017, the user attempted
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 Legacy Wallet Lockout: 17-Word Phrase Incompatible With Recovery Tool
Exchange custody
Indeterminate 2017
Between November and December 2017, multiple Blockchain.info users discovered they could not access legacy wallets created years earlier, despite possessing com
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 Legacy Wallet Access Failure: 17-Word Recovery Phrase Incompatibility
Exchange custody
Blocked 2017
Beginning in late November 2017, multiple users including Ople, nwankwotech, and Boldos reported simultaneous access failures to Blockchain.info wallets created
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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.

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