Bitcoin security · keys, access, responsibility
Keep your access.
You have chosen a wallet. But where is the backup — and who else can move the funds? Explore keys, recovery and storage mistakes, from early losses to recent incidents.
16 articles in this collectionWallets and keys
Understand what you are storing
Where Bitcoin exists
Why a balance is a sum of unspent outputs and a wallet holds keys rather than coins.
Read articlePractical guideHow to choose a wallet without losing access
Mobile, desktop and hardware wallets: purpose, trade-offs and the rules of reliable backup.
Read articleBIP 39 · 2013Twelve Words Are Not a Password
How BIP 39 turns randomness into a readable backup and why people should not invent the words.
Read articleResearch · 2011–2015Why a Phrase from Memory Made a Bad Wallet
The brainwallet experiment: when a convenient human phrase became a predictable private key.
Read articleBackups and recovery
Keep access — and be able to restore it
8,000 BTC beneath a landfill
A drive reached a landfill, but the decisive loss came earlier: the only usable copy of access disappeared.
Read articleBitcoin Core · 2025–2026An Old wallet.dat Cannot Simply Be Opened
The end of BDB wallet loading and a rare migration bug show why recovery begins with copies.
Read articleBitcoin Core · Fix merged September 9, 2026The Wallet Was Called Corrupted Even Though the Keys Were Still There
How a Bitcoin Core 31.0 compatibility check prevented some Miniscript descriptor wallets from loading—and why a corruption warning does not always mean lost coins.
Read articleBitcoin Core · Fix merged September 9, 2026When the Order of Two PSBTs Decided Whether a Signature Worked
How combinepsbt lost a requested sighash type and why a valid signature could be rejected solely because of file order.
Read articleControl and custody
Who controls your BTC
Bitcoin interest accounts: who pays the yield?
Why Bitcoin itself creates no yield, who receives control of the keys and what risks hide behind the familiar word “deposit.”
Read articleCustody · BTC or a product shareThe Fund Holds BTC. What Does the Investor Hold?
Why a bitcoin exchange-traded product can follow Bitcoin’s price without giving its shareholder the same control as a private key.
Read articleCustody · Coinbase 2025 / Trezor 2026The Data Leaked, the Keys Did Not. Who Controls Your BTC?
Two incidents without stolen private keys reveal the difference between self-custody and an account with an intermediary.
Read articleMistakes and incidents
When protection failed
The first major reported theft: 25,000 BTC
A backup existed but could not reverse a transfer after someone gained access to the live wallet.
Read articleBitcoin Depot · March 202650.903 BTC Left After Credentials Were Compromised
How access to a corporate system enabled an unauthorized BTC transfer without breaking Bitcoin—and why the entire path to signing must be protected.
Read articleBTCPay Server · August 2026The File That Became a Key: Theft Through BTCPay Server
How exposed authorization files gave attackers access to LND Lightning nodes and why version 2.4.2 required an urgent update.
Read articleCOLDCARD · July 2026The Hardware Wallet That Generated Keys with Too Little Randomness
How a COLDCARD firmware defect reduced seed entropy and why updating the device does not repair a wallet that already exists.
Read articleBitcoin Core · Fix merged September 2, 2026When a Wallet Name Becomes a Command
How a crafted wallet name could alter a walletnotify command and why RPC access should not imply access to the operating system.
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