CustodyStress
Archive › Structural dependencies › Single-Person Knowledge
Part of the CustodyStress archive of observed Bitcoin custody incidents

Single-Person Knowledge

Cases where only one person held the operational knowledge required to access the Bitcoin. When that person became unavailable, no alternate recovery path existed.

Single-person knowledge concentration is the most frequently observed structural dependency in the archive, present in 596 cases. A 80% blocked rate among determinate cases reflects that this dependency is not merely common but decisive — when the sole knowledgeable person is unavailable, no alternate path exists.

245
Blocked
14
Constrained
47
Survived
290
Indeterminate

85% of determinate cases resulted in blocked or constrained access.

596 observed cases
Blocked
245 (41%)
Constrained
14 (2%)
Survived
47 (8%)
Indeterminate
290 (49%)
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
Mycelium Android Wallet: Forgotten PIN Blocks Access to Received Bitcoin
Software wallet
Indeterminate 2019
In May 2019, a Mycelium wallet user created a new wallet on an older Android phone and recorded the 12-word mnemonic seed phrase on paper. A 6-digit PIN was the
Oslo Bitcoin Millionaire's Escape From Armed Home Invader (2019)
Hardware wallet (single key)
Survived 2019
In May 2019, a Bitcoin millionaire residing in Oslo, Norway became the target of an armed home invasion. The attacker confronted the victim at his apartment, bu
Lost Electrum Wallet Password: wallet.dat File Encrypted, No Backup Credential
Software wallet
Indeterminate 2019
In February 2019, a forum user identified as bitbemining posted a custody failure case involving an Electrum wallet. The user possessed the encrypted wallet.dat
Electrum Seed Phrase Mismatch: Valid Addresses, Missing Funds
Software wallet
Indeterminate 2018
In January 2018, forum user 'thenarog' encountered a nuanced custody failure involving an Electrum desktop wallet. The user held a wallet.dat backup file protec
Forgotten wallet.dat Password: 13.8 BTC Locked Since 2013
Software wallet
Indeterminate 2018
On 2 March 2018, a Bitcoin holder identified as fabriciofenenga posted to the Bitcoin Technical Support forum seeking password recovery assistance for a wallet.
PIVX Encrypted Wallet Access Failure After System Update and Forced Shutdown
Software wallet
Indeterminate 2018
In May 2018, a user encrypted a PIVX wallet using PIVX Core version 3.1.0.2 on Windows 64-bit and confirmed the passphrase worked across multiple unlock cycles
131 BTC Inaccessible: Forgotten Wallet Password, No Recovery Mechanism
Software wallet
Indeterminate 2018
In December 2018, a BitcoinTalk user known as 'jackang' posted a public plea for help recovering access to a wallet containing 131 BTC. The wallet had been crea
Bither Desktop Wallet Application Crash: 3-Year Recovery via Password Rediscovery
Software wallet
Survived 2018
Sygun created a Bither wallet in March 2018 holding approximately 0.019 BTC. At an unspecified point, the Bither application ceased launching entirely—double-cl
College-Era Bitcoin Miner: Wallet.dat Recovered, But Addresses Empty
Software wallet
Indeterminate 2018
In early 2018, a Bitcoin Forum user identified as cdcine sought help recovering Bitcoin he had mined during his college years using Bitcoin Core version 0.3.23,
Bitcoin-Qt HD Wallet Change Address Lost to Deleted wallet.dat File
Software wallet
Blocked 2018
In May 2018, a BitcoinTalk user identified as Tuee22 performed a transaction sending 0.01 BTC to an online vendor using Bitcoin-Qt. The user had maintained a si
4 BTC Inaccessible in BIP38-Encrypted Paper Wallet After Passphrase Loss
Software wallet
Indeterminate 2018
In February 2018, a Bitcoin holder discovered that access to 4 BTC distributed across three BIP38-encrypted paper wallet addresses had become impossible due to
Ledger Nano S Seed Phrase Transcription Error: Duplicate Words at Positions 9 and 12
Hardware wallet (single key)
Indeterminate 2018
In September 2018, a BitcoinTalk user identified as efreeet reported a custody access failure on a Ledger Nano S hardware wallet. The user had originally genera
Corrupted wallet.dat Recovery from 2009 Hard Drive: Hex Search Method
Software wallet
Indeterminate 2018
In January 2018, a BitcoinTalk user reported discovering a hard drive containing a wallet.dat file created during 2009 Bitcoin mining. The drive had suffered si
Lost Final Word of Ledger Nano S 24-Word Seed: 110,000 Dogecoin Case
Hardware wallet (single key)
Indeterminate 2018
On March 8, 2018, a BitcoinTalk forum user identified as Ma1k reported losing the 24th word of a Ledger Nano S BIP39 recovery seed phrase. The loss occurred aft
Bitcoin Knots Wallet Access Lost After SSD Migration: wallet.dat Location Mismatch
Software wallet
Indeterminate 2018
In May 2018, an inexperienced Bitcoin user (mortamuerte) initiated blockchain synchronization using Bitcoin Knots, a Bitcoin Core fork, on a laptop SSD. Partway
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
Kleiman Estate v. Craig Wright: Bitcoin Access Blocked by Knowledge Concentration
Unknown custody system
Blocked 2018
David Kleiman, a computer forensics expert in Palm Beach County, Florida, died in April 2013. His brother Ira Kleiman later alleged that David and Craig Steven
Danny Aston Home Invasion: UK's First Documented Crypto-Targeted Physical Attack — 2018
Unknown custody system
Indeterminate 2018
On an unspecified date in 2018, four armed men invaded the Moulsford, Oxfordshire residence of cryptocurrency trader Danny Aston. The assault was motivated by a
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
Cryptocurrency Traders Robbed at Gunpoint in Moulsford, Oxfordshire
Unknown custody system
Blocked 2018
Danny Aston and Amy Jay, cryptocurrency traders operating in the UK, were victims of armed robbery in Moulsford, Oxfordshire. The perpetrators held them at gunp
Bitcoin Core Wallet Passphrase Rejected: $400 USD Inaccessible
Software wallet
Blocked 2018
In September 2018, a Bitcoin Core user reported being locked out of their encrypted software wallet containing approximately $400 USD in Bitcoin. The wallet had
Electrum Wallet Lost to Laptop Hardware Failure: No Seed Phrase Backup
Software wallet
Indeterminate 2018
On October 12, 2018, a BitcoinTalk forum user identified as Chabole007 reported losing access to an Electrum software wallet after their laptop experienced hard
Recovered 12-Word Seed Phrase but Balance Shows Zero: Imported Address Problem
Software wallet
Blocked 2018
In September 2018, a Bitcoin holder attempted to recover wallet access after forgetting which software they had originally used. They obtained a 12-word recover
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
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Structural dependencies
By stress condition
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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