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

Single-Person Knowledge — Software wallet

Cases where only one person understood how to access a mobile wallet. When that person became unavailable or failed to communicate access credentials, no independent recovery path existed.

77% of all Software wallet cases in the archive involve this structural dependency. The blocked rate among them is 81% — 12 points above the archive-wide blocked rate of 69%. The most common recovery path is password bruteforce.

121
Blocked
5
Constrained
24
Survived
201
Indeterminate

84% of determinate cases resulted in blocked or constrained access.

351 observed cases
Blocked
121 (34%)
Constrained
5 (1%)
Survived
24 (7%)
Indeterminate
201 (57%)
Forgotten Passphrase Locks Desktop Wallet for 8 Years; btcrecover Enables Recovery
Software wallet
Survived 2013
In 2013, this individual created a Bitcoin wallet using desktop software, securing it with a passphrase. The holder subsequently lost memory of that passphrase
BitcoinTalk User syuyu Locked Out of Wallet With ~32-Character Passphrase (January 2014)
Software wallet
Indeterminate 2013
In January 2014, a BitcoinTalk user known as 'syuyu' posted in an encrypted wallet recovery thread describing a locked software wallet they could no longer acce
1990 BTC Forgotten Passphrase: Pakistani Investor's Failed Recovery Attempts (2013)
Software wallet
Indeterminate 2013
In November 2013, a BitcoinTalk forum user identified as 'Britman' disclosed a significant custody failure affecting 1990 BTC accumulated throughout 2012 at pri
Rahazan Develops and Shares PowerShell Wallet Recovery Script (2013)
Software wallet
Indeterminate 2013
In 2013, a BitcoinTalk user identifying as Rahazan faced a common early custody problem: an encrypted Bitcoin-Qt wallet with a forgotten passphrase. Rather than
BitcoinTalk User kentt Recovers Encrypted Wallet via Community Brute-Force Script (June 2013)
Software wallet
Survived 2013
In June 2013, BitcoinTalk user kentt posted confirmation of a successful wallet recovery using community-developed brute-force scripts circulated in topic 85495
SP4RK7 Locked Out of Protoshares Wallet: Single-Character Password Error, Recovery Bounty Offered
Software wallet
Indeterminate 2013
On November 30, 2013, BitcoinTalk user SP4RK7 posted in the encrypted wallet recovery thread describing a Protoshares wallet locked with encryption that appeare
BitcoinTalk User ez1btc: Encryption Password Transcription Error Blocks Large Bitcoin Wallet
Software wallet
Indeterminate 2012
In the encrypted wallet recovery thread on BitcoinTalk, user 'ez1btc' documented a custody failure rooted in transcription error rather than forgetfulness. At t
Lost Private Key in 2012 Bitcoin Core Wallet: 5 mBTC Unspendable
Software wallet
Blocked 2012
Gemwolf installed Bitcoin Core 0.6.3 in 2012, performed brief mining activity, and abandoned the wallet after one day. In November 2022, while searching old sto
Deep Freeze Software Erases Bitcoin Wallet.dat Before Incoming Payment
Software wallet
Blocked 2012
In September 2012, a Bitcoin user operating under the handle blackjhon909 discovered that their Bitcoin wallet had become inaccessible following an unexpected s
Mac Formatted Without Backup: wallet.dat Recovery Attempt (2012)
Software wallet
Indeterminate 2012
On July 5, 2012, forum user Mashrock reported formatting a Mac computer running OS X 10.7 and subsequently losing access to Bitcoin stored in a wallet.dat file.
Accidental Windows User Account Deletion: 78 BTC Wallet.dat Lost Without Backup
Software wallet
Indeterminate 2012
On April 28, 2012, a Bitcoin Forum user under the alias 'spinnin' reported a critical custody failure. The user had generated 78 BTC using the official Bitcoin
250 BTC Lost After Windows Profile Deletion and Repeated System Restore Overwrites
Software wallet
Blocked 2012
In early 2012, a Windows user operating under the handle kentrolla reported losing access to a Bitcoin wallet containing approximately 250 BTC. The wallet.dat f
1,300 BTC Inaccessible: BitLocker Encryption Key Lost on Failed Flash Drive
Software wallet
Indeterminate 2012
In June 2012, forum user mb300sd disclosed on BitcoinTalk's 'known lost bitcoins' thread that approximately 1,300 BTC had become permanently inaccessible due to
Early CPU Miner Loses 27,000 BTC to Unrecoverable Drive Failure
Software wallet
Blocked 2012
Dalkore mined 27,000 BTC during Bitcoin's earliest period using CPU mining, when the network was still in its first year and coins carried no meaningful market
Opticbit Loses 2 BTC After CyanogenMod 9 Flash Without Locatable Wallet Backup
Software wallet
Blocked 2012
On June 25, 2012, a Bitcoin user operating under the handle opticbit reported the loss of 2 BTC stored in a mobile wallet on an Android phone. The loss occurred
Brad Yasar: Desktop-Mined Bitcoin Locked by Forgotten Passwords
Software wallet
Blocked 2012
Brad Yasar, a Los Angeles-based entrepreneur, mined Bitcoin on multiple desktop computers during the network's earliest years when mining was accessible to indi
2012 Bitcoin Core Wallet Lost to PC Crash: Backup Files Exist, Access Blocked
Software wallet
Indeterminate 2012
In August 2020, a Bitcoin holder posted to Bitcoin Stack Exchange describing a custody failure spanning eight years. The individual had downloaded a GUI miner o
2012 Electrum Wallet Recovery Attempt: 9-Word Seed Phrase, Missing wallet.dat Backup
Software wallet
Indeterminate 2012
In May 2021, a BitcoinTalk user identified as philipp0815 posted a recovery request for Bitcoin held in an Electrum wallet created in 2012. The user possessed o
Anonymous Reddit User: 7,500 BTC Inaccessible Due to Forgotten Wallet Password
Software wallet
Blocked 2012
An anonymous Reddit user posted in 2014 about a significant custody failure: he had purchased approximately 7,500 Bitcoin in 2012 and stored them in an encrypte
Wallet Encryption Without Post-Encryption Backup: 5 BTC Change Address Lost
Software wallet
Indeterminate 2012
In December 2012, a BitcoinTalk user reported a custody failure involving wallet encryption and backup timing. The user had received 10 BTC across two transacti
Fiyasko's Forgotten Passphrase: Mining Savings Lost to Single Point of Failure (2012)
Software wallet
Indeterminate 2012
In December 2012, a Bitcoin miner operating under the username Fiyasko (also known as JackRabiit) created a dedicated savings wallet to store one month of accum
Brainwallet Passphrase Mismatch — Address Generation Failure After Fund Transfer
Software wallet
Indeterminate 2012
In December 2012, a BitcoinTalk user identified as 'thoughtfan' encountered a critical custody failure after using brainwallet.org to generate a Bitcoin address
Seed unavailable — Bitcoin Core (2012)
Software wallet
Indeterminate 2012
In the era before hierarchical deterministic wallets and seed phrases, Bitcoin holders using the original Bitcoin Core client stored their private keys in a sin
Unauthorized Drive Format and Corrupted Wallet File Recovery Failure (2011)
Software wallet
Indeterminate 2011
On September 17, 2011, a Bitcoin holder identified as cablepair discovered that an office network administrator had reformatted the hard drive of a shared offic
Corrupted wallet.dat Recovery After Hard Drive Failure: 2011 Case Study
Software wallet
Indeterminate 2011
In May 2011, forum user zrataj (John) experienced a critical storage failure when his hard drive crashed, destroying both his primary wallet.dat file and the ba
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Related pages
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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