CustodyStress
ArchiveSingle-Person Knowledge › Vendor Lockout
Part of the CustodyStress archive of observed Bitcoin custody incidents

Single-Person Knowledge — Vendor Lockout

Cases where operational knowledge of the custody arrangement existed only with the holder. No second person had sufficient understanding to execute recovery independently. This page shows archive cases where both conditions were present.

29% of all Vendor Lockout cases in the archive involve this structural dependency. Among them, 80% of determinate cases resulted in a blocked outcome. The most common recovery path is exchange support.

28
Blocked
5
Constrained
2
Survived
21
Indeterminate

94% of determinate cases resulted in blocked or constrained access.

56 observed cases
Blocked
28 (50%)
Constrained
5 (9%)
Survived
2 (4%)
Indeterminate
21 (38%)
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
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 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
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
Mycelium Mobile Wallet Balance Access Failure — December 2017
Software wallet
Indeterminate 2017
In mid-December 2017, a Bitcoin user (Myrr) discovered a critical custody access failure in the Mycelium mobile wallet on their iPhone. The user had purchased B
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
KipCoin Exchange Linode Hosting Compromise: October 2014 Breach, February 2015 Disclosure
Exchange custody
Indeterminate 2015
KipCoin operated as a custodial Bitcoin exchange running infrastructure on Linode virtual private servers. In June 2014, Linode suffered a security breach that
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
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
BitInstant Exchange Collapse: Charlie Shrem Arrest Freezes Customer Funds
Exchange custody
Blocked 2014
BitInstant operated as one of the earliest and most prominent custodial Bitcoin exchanges in the United States, co-founded by Charlie Shrem with backing from th
Mt. Gox Collapse Overshadows Father's Estate: Unrecover­able Bitcoin Loss
Exchange custody
Blocked 2014
Around 2012, a Reddit user posted in a Mt. Gox horror story thread describing a custody failure layered with family loss. His father had died approximately one
Armory Wallet Synchronization Failure: Access Restored After Software Upgrade
Software wallet
Survived 2013
In October 2013, a BitcoinTalk user holding approximately 0.1008 BTC in an encrypted Armory wallet encountered a critical access failure. The user possessed bot
Blockchain.info Web Wallet (2013): Silent Login Failure, Unresolved After 3 Months
Exchange custody
Blocked 2013
In late 2013, a user created a Bitcoin wallet on blockchain.info, then one of the most popular web-based custodial platforms. The wallet remained accessible dur
Blockchain.info Web Wallet: Imported Private Key Vanished After Sync Popup
Exchange custody
Blocked 2013
In February 2013, a BitcoinTalk user (BurtW) generated a vanity address using vanitygen and imported the private key into his Blockchain.info web wallet account
Intersango Exchange Collapse: 2000 BTC User Funds Retained by Operator — Norman v. Strateman
Exchange custody
Blocked 2012
Intersango, a UK-based Bitcoin exchange co-founded by Amir Taaki and Patrick Strateman, ceased operations in 2012 after losing its banking relationship. At the
BTCex Unexpected Maintenance Closure and Permanent Platform Shutdown (July 2012)
Exchange custody
Blocked 2012
BTCex operated as a custodial Bitcoin exchange during the early market period. In May 2011, the platform suffered a critical security breach resulting in the lo
BitMarket.eu: Operator Speculation and Bitcoinica Collapse Froze 18,787 BTC in Customer Funds
Exchange custody
Blocked 2012
BitMarket.eu launched in April 2011 as a Polish peer-to-peer Bitcoin exchange. The platform operator, Maciej Trębacz, made a critical decision to invest custome
Bitomat.pl Exchange Loses 17,000 BTC to AWS Instance Restart
Exchange custody
Constrained 2011
Bitomat.pl operated as the third-largest Bitcoin exchange globally and the largest in Poland during the early 2011 cryptocurrency market. On July 26, 2011, the
BTCex Exchange Users Discover 83% Bitcoin Missing After Temporary Closure
Exchange custody
Blocked 2011
BTCex was a Russian-based cryptocurrency exchange founded in September 2010 that facilitated trades between bitcoin and fiat currencies including Russian Rubles
MyBitcoin.com Custody Collapse (July 2011): 78,747 BTC Lost, Partial Refund, Operator Never Identified
Exchange custody
Blocked 2011
MyBitcoin.com, launched in 2010, became one of the first popular custodial Bitcoin web wallet services at a time when hardware wallets did not exist and self-cu
50btc Pool Mining Loss: 2–3 BTC Trapped in Defunct Pool, Virtual Disk Recovery Failed
Exchange custody
Indeterminate 2010
In 2010, a user identified as Zagal downloaded and ran 50miner, a mining client for the 50btc pool, on his personal computer for approximately one week. During
3,000 BTC Locked on Discontinued Blockchain.com Wallet: Missing Email Address Blocks Recovery
Exchange custody
Blocked 2009
Ice22 acquired 3,000 BTC in June 2009 through an intermediary claiming to represent a Swiss or Swedish Bitcoin promotion entity. The acquisition process include
Inputs.io Security Breach and Platform Collapse — 4,100 BTC Lost
Exchange custody
Blocked
Inputs.io operated as a hosted web wallet service in the early Bitcoin era, when best practices for key management were still crystallizing. The platform genera
Bitcoinpaperwallet.com Scam: Paper Wallet Generator as Theft Vector
Software wallet
Blocked
A Bitcoin holder used bitcoinpaperwallet.com to generate a paper wallet, a common practice among users seeking offline key storage. The website appeared functio
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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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