CustodyStress
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Part of the CustodyStress archive of observed Bitcoin custody incidents

Shared Dependency Failure

Cases where custody components that appeared independent shared a common underlying dependency — the same vendor, the same physical location, or the same keyholder. When the shared root failed, multiple recovery paths failed simultaneously. Shared dependency failures are custody failures that appear structurally sound until stress is applied. A holder who stores one seed phrase copy at home and a second copy at their office has two copies — but if both locations are accessible to the same authority during a legal seizure, the separation provides no protection. A multisig arrangement that uses two different hardware wallet brands but purchases both through the same vendor account, or stores both in the same safe, has apparent redundancy but a single failure point. The archive documents three recurring shared-root patterns: shared physical location (multiple backups colocated, destroyed or seized together); shared vendor root (multiple custody components dependent on the same platform, which fails as a single unit); and shared keyholder (multiple signing roles held by the same person, defeating multisig threshold protections). These patterns are often invisible during normal operation — the setup appears redundant until the shared root is stressed.

208 cases match this pattern in the archive. Among cases with a determinate outcome, 61% resulted in permanently blocked access, 4% in recovered access, and 35% in constrained recovery. 79% of cases in this pattern involved exchange custody.

97
Blocked
55
Constrained
7
Survived
49
Indeterminate

96% of determinate cases resulted in blocked or constrained access.

208 observed cases
Blocked
97 (47%)
Constrained
55 (26%)
Survived
7 (3%)
Indeterminate
49 (24%)
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
Matthew Mellon's $193M XRP Estate: Cold Wallets, No Keys, No Plan
Hardware wallet (single key)
Constrained 2018
Matthew Mellon, a member of the prominent Mellon banking family, became a significant cryptocurrency investor in the mid-2010s. His $2 million investment in XRP
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
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
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
Mark Frauenfelder's 7.4 BTC: Seed Phrase Discarded by Housecleaner, Recovered via Hardware Vulnerability
Hardware wallet (single key)
Survived 2017
Mark Frauenfelder, editor-in-chief of Boing Boing and Wired contributor, purchased 7.4 Bitcoin in January 2016 for approximately $3,000 and transferred it to a
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
Blockchain.info Legacy Wallet Upgrade Failure: Lost Access Without Seed Phrase
Exchange custody
Indeterminate 2017
In November 2017, a Blockchain.info user (jameslewis123) discovered that wallets created in 2014–2015 could no longer be accessed after an extended dormancy per
BTC-e Exchange Seized by U.S. DOJ: 1 Million Users Lose Access (July 2017)
Exchange custody
Blocked 2017
BTC-e, founded in 2011 and headquartered in Russia, operated as an unlicensed money transmitter for six years, processing over $9 billion in cryptocurrency tran
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
Blockchain.info Account Lockout: Forgotten Password and Missing Recovery Phrase (2013 Wallet)
Exchange custody
Indeterminate 2017
A BitcoinTalk forum user identified as MARK 888 reported in October 2017 that they had lost access to a Blockchain.info wallet created around 2013. The user ret
Homeland Security Bitcoin Seizure: Unencrypted Seed Phrase Discovered During Search
Software wallet
Blocked 2017
BurtW, a BitcoinTalk forum user, revealed in April 2017 that he had been arrested and that Homeland Security conducted searches of both his home and office. Dur
Custodial Wallet Provider Bankruptcy: 2012 Bitcoin Purchase Permanently Inaccessible
Exchange custody
Blocked 2017
In November 2017, a Bitcoin holder disclosed that they had purchased Bitcoin in 2012 but subsequently lost access to their holdings after the company maintainin
Uphold Freezes 165 BTC Business Account: Inconsistent Enforcement and Unresolved Access
Exchange custody
Blocked 2017
Oleg operated Nexchange.io, a cryptocurrency exchange that used Uphold as a liquidity provider. In 2017, he executed a single trade of 165 BTC (approximately $1
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Structural patterns
Other structural patterns
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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