Wallet [Bitcoin]

The wallet does not actually contain coins. Rather, it stores the keys that allow you to spend the coins that are associated with a specific Bitcoin address.

The actual value of coins in a wallet is determined by traversing the entire blockchain and summing up all credit/debit transactions values for the addresses stored in the wallet.

The wallet is not only a collection of keys. It also contains transactions, accounting information, settings and information about the blockchain.

Reading/writing wallet.dat

Bitcoin core uses Berkeley DB (BDB) to read/write wallet files (wallet.dat).

Apparently, the entries in the wallet have one of the following types (cf src/wallet/walletdb.cpp, function ReadKeyValue):

name: an address book name
purpose:
tx: a transaction
acentry: an accounting entry
watchs
key: Public key (class CPubKey) followed by a private key (class CPrivKey)
mkey: Master key (class MasterKey)
ckey: an encrypted key
keymeta
watchmeta
defaultkey: The default receiving address' key
pool: a keypool entry
version: The version of the software that wrote the wallet
cscript: a script
orderposnext
destdagta
hdchain
bestblock: a pointer to the best blockchain seen. The client needs this information for a rescan after a restore of a wallet from a backup.
wkey: Public key (class CPubKey) followed by a wallet key (class CWalletKey). Apparently no longer used.
setting: used to store userinterface settings. It's no longer used. For backward compatibility, however, there is still one entry so that client with a version less than 0.4.0 can read a wallet.

See also the function ReadKeyValue() in src/wallet/walletdb.cpp.

Wallet [Bitcoin]

Reading/writing wallet.dat

Links

See also