CustodyStress
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Part of the CustodyStress archive of observed Bitcoin custody incidents
Single-Person KnowledgeExchange custody

Single-Person Knowledge — Exchange custody

Cases where only one person understood how to access an exchange account. When that person became unavailable — through death, incapacity, or absence — no one else could navigate the account recovery process.

38% of all Exchange custody cases in the archive involve this structural dependency. The blocked rate among them is 80% — 11 points above the archive-wide blocked rate of 69%. The most common recovery path is exchange support.

47
Blocked
6
Constrained
6
Survived
41
Indeterminate

90% of determinate cases resulted in blocked or constrained access.

100 observed cases
Blocked
47 (47%)
Constrained
6 (6%)
Survived
6 (6%)
Indeterminate
41 (41%)
Seed Phrase Lost to Household Disposal, Partial Password Known—Blockchain.info Hosted Wallet Inaccessible
Exchange custody
Indeterminate 2020
In April 2020, a Blockchain.info user experienced near-total loss of account recovery materials. The user maintained his seed phrase in two locations: a physica
Blockchain.info Wallet Access Lost: Destroyed Phone Note, Discarded Seed Paper, Partial Password
Exchange custody
Indeterminate 2020
In April 2020, a forum user described a friend's custody access failure involving a Blockchain.info hosted wallet (the platform later rebranded to Blockchain.co
Blockchain.com Wallet Locked: Partial Recovery Phrase and Lost Secondary Withdrawal Password
Exchange custody
Indeterminate 2020
In September 2020, a BitcoinTalk user identified as sa14 reported complete inability to access a Blockchain.com wallet created on November 29, 2017, despite pos
Pre-2014 Blockchain.info Wallet: Non-Standard Mnemonic Format Blocks Recovery
Exchange custody
Indeterminate 2019
In May 2019, a Bitcoin holder identified as pizzdaniel posted to BitcoinTalk describing a multi-year custody failure involving wallets created on blockchain.inf
Blockchain.com Web Wallet Access Failures: Lost Passwords and Inaccessible Email Recovery
Exchange custody
Blocked 2019
Between 2013 and 2019, several users created Bitcoin wallets on blockchain.com (formerly blockchain.info), a web-based custodial platform popular during early B
QuadrigaCX Exchange Collapse: $190M Bitcoin Lost After Owner's Death
Exchange custody
Blocked 2019
QuadrigaCX was a Canadian cryptocurrency exchange that collapsed in 2019 following the sudden death of its founder and sole operator. The exchange held approxim
QuadrigaCX Exchange Collapse: CEO Death Blocks Access to $190M in Customer Cryptocurrency
Exchange custody
Blocked 2019
QuadrigaCX, founded in 2013 and operating as one of Canada's largest cryptocurrency exchanges, ceased operations in January 2019 following the death of CEO and
QuadrigaCX Gerald Cotten Death: C$190M in Cold Storage Permanently Inaccessible
Exchange custody
Blocked 2018
Gerald Cotten, 30, founded and operated QuadrigaCX as Canada's largest cryptocurrency exchange. He managed the platform's operations, customer support, and crit
Mt. Gox Account Access Permanently Blocked Following Owner Death and Credential Reset
Exchange custody
Blocked 2018
Mt. Gox ceased operations in February 2014 following the loss of approximately 850,000 Bitcoin. Users with dormant accounts on the platform faced an immediate c
Mobile Wallet Loss: Phone Format Destroys All Recovery Credentials
Exchange custody
Indeterminate 2018
On April 22, 2018, BitcoinTalk forum user Calypso_Dame reported a critical custody access failure resulting from a mobile phone format operation. The user had r
Facebook Mining Scam: $27,830 in Bitcoin Lost After Credential Compromise
Exchange custody
Blocked 2018
A user new to Bitcoin was introduced to cryptocurrency via Facebook by an account claiming mining expertise. The contact offered to help the user purchase Bitco
Blockchain.info Wallet Password Lost, No Seed Backup: Recovery Blocked
Exchange custody
Indeterminate 2018
In July 2018, a Bitcoin holder transferred funds to his wife's blockchain.info mobile wallet during a phone transition. The wife subsequently forgot the wallet
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
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
Blockchain.info Wallet Lockout: Documented Seed Phrase Fails Validation
Exchange custody
Blocked 2017
Sir11k created a Blockchain.info custodial wallet in June 2017 with approximately €20 worth of Bitcoin. Upon account creation, the platform provided a 12-word B
Blockchain.info Watch-Only Import Without Private Key Retention
Exchange custody
Blocked 2017
In June 2017, a Bitcoin Talk forum user (amirheavy666) discovered that approximately 0.00027375 BTC accumulated on a Blockchain.info wallet created around 2014
Blockchain.info Hosted Wallet Recovery Attempt: Partial Password, No Seed Backup
Exchange custody
Indeterminate 2017
In October 2017, a BitcoinTalk user identified as Parodium reported being locked out of a blockchain.info wallet created years earlier. The user retained email
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
Blockchain.info Wallet: Lost Password and Recovery Phrase on Phone
Exchange custody
Blocked 2017
In June 2017, a Blockchain.info user posted on Bitcoin Stack Exchange reporting the loss of both their wallet password and 12-word recovery phrase after losing
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
Colorado Bitcoin Investor Death: Family Discovery and Coinbase Estate Transfer 2017
Exchange custody
Survived 2017
A Colorado-based Bitcoin investor died suddenly in 2017 without informing his family of his cryptocurrency holdings. The family had no initial awareness that he
Teenager Locked Out of Blockchain.info Wallet After Password Change – No Seed Backup
Exchange custody
Indeterminate 2017
In late October 2017, a Russian Bitcoin user (forum username: see123123) discovered they could no longer access their Blockchain.info hosted wallet. The user ha
Deceased Bitcoin Miner: Funds Locked on Coinbase, Lost on SnapCard Closure
Exchange custody
Blocked 2016
A Bitcoin miner died intestate in 2016, leaving behind mining equipment and active cryptocurrency accounts on Coinbase and SnapCard, a now-defunct wallet servic
Block.io Permanent Loss: Forgotten PIN and Missing Secret Mnemonic Backup
Exchange custody
Blocked 2016
In February 2016, a BitcoinTalk user identifying as CaRLoSXXX posted a distress message after losing access to their Block.io wallet. Block.io is a non-custodia
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
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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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