Wallet encryption - Revision history

JonathanCross: Updating link to Bitcoin Core's wallet.dat info

2017-09-17T10:36:33Z

Updating link to Bitcoin Core's wallet.dat info

← Older revision		Revision as of 10:36, 17 September 2017
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	This page describes the algorithm used for encrypting the '''[[Wallet#~~Bitcoin_Qt~~\|wallet.dat]]''' file used in the original [[Bitcoin client]].		This page describes the algorithm used for encrypting the '''[[Wallet#Bitcoin_Core\|wallet.dat]]''' file used in the original [[Bitcoin client]].

	Wallet encryption uses [https://en.wikipedia.org/wiki/AES-256 <span title="Advanced Encryption Standard with 256 bit key and Cipher Block Chaining">AES-256-CBC</span>] to encrypt only the private keys that are held in a wallet. The keys are encrypted with a master key		Wallet encryption uses [https://en.wikipedia.org/wiki/AES-256 <span title="Advanced Encryption Standard with 256 bit key and Cipher Block Chaining">AES-256-CBC</span>] to encrypt only the private keys that are held in a wallet. The keys are encrypted with a master key

JonathanCross: Formatting RPC commands using code font and linking to list of all RPC commands. Also linking to more info on the wallet.dat file, AES-256 and SHA-512.

2016-04-06T19:54:58Z

Formatting RPC commands using code font and linking to list of all RPC commands. Also linking to more info on the wallet.dat file, AES-256 and SHA-512.

Sgornick: With many bitcoin clients, specifically link to the article that describes this as being the Bitcoin-Qt/bitcoind client.

2013-03-31T21:35:09Z

With many bitcoin clients, specifically link to the article that describes this as being the Bitcoin-Qt/bitcoind client.

← Older revision		Revision as of 21:35, 31 March 2013
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	This is the wiki page describing the algorithm used for encrypting of the wallet.dat used in the original Bitcoin client.		This is the wiki page describing the algorithm used for encrypting of the wallet.dat used in the original [[Bitcoin client]].

	Wallet encryption uses AES-256-CBC to encrypt only the private keys		Wallet encryption uses AES-256-CBC to encrypt only the private keys

Sgornick: /* Implementation details of wallet encryption */ Add message regarding the need to create new backups after encryption.

2012-09-30T19:38:20Z

Implementation details of wallet encryption: Add message regarding the need to create new backups after encryption.

← Older revision		Revision as of 19:38, 30 September 2012
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	a new key from pool is used and the wallet is unlocked (or unencrypted).		a new key from pool is used and the wallet is unlocked (or unencrypted).

	When wallet passphrase enrcyption becomes enabled, any unused keys from the keypool are flushed (marked as used) and new keys protected with encyption are added.		When wallet passphrase enrcyption becomes enabled, any unused keys from the keypool are flushed (marked as used) and new keys protected with encyption are added. <span style="color:red">For this reason, make a new backup of your wallet so that you will be able to recover the keys from the new key pool should access to your backups be necessary.</span>

	[[Category:Technical]]		[[Category:Technical]]

Sgornick: Mention how the keypool is flushed upon encryption.

2012-09-29T20:08:28Z

Mention how the keypool is flushed upon encryption.

← Older revision		Revision as of 20:08, 29 September 2012
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	Note that the keypool continues to be topped up on various occasions when		Note that the keypool continues to be topped up on various occasions when
	a new key from pool is used and the wallet is unlocked (or unencrypted).		a new key from pool is used and the wallet is unlocked (or unencrypted).

			When wallet passphrase enrcyption becomes enabled, any unused keys from the keypool are flushed (marked as used) and new keys protected with encyption are added.

	[[Category:Technical]]		[[Category:Technical]]

Gavinandresen at 14:07, 4 April 2012

2012-04-04T14:07:54Z

← Older revision		Revision as of 14:07, 4 April 2012
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	Note that the keypool continues to be topped up on various occasions when		Note that the keypool continues to be topped up on various occasions when
	a new key from pool is used and the wallet is unlocked (or unencrypted).		a new key from pool is used and the wallet is unlocked (or unencrypted).

			[[Category:Technical]]

Gavinandresen: Pasted from the 0.4 release notes

2012-04-04T14:05:52Z

Pasted from the 0.4 release notes

← Older revision		Revision as of 14:05, 4 April 2012
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	This is the wiki page describing the algorithm used for encrypting of the wallet.dat used in the original Bitcoin client.		This is the wiki page describing the algorithm used for encrypting of the wallet.dat used in the original Bitcoin client.

			Wallet encryption uses AES-256-CBC to encrypt only the private keys
			that are held in a wallet. The keys are encrypted with a master key
			which is entirely random. This master key is then encrypted with
			AES-256-CBC with a key derived from the passphrase using SHA512 and
			OpenSSL's EVP_BytesToKey and a dynamic number of rounds determined by
			the speed of the machine which does the initial encryption (and is
			updated based on the speed of a computer which does a subsequent
			passphrase change). Although the underlying code supports multiple
			encrypted copies of the same master key (and thus multiple passphrases)
			the client does not yet have a method to add additional passphrases.

			At runtime, the client loads the wallet as it normally would, however
			the keystore stores the keys in encrypted form. When the passphrase
			is required (to top up keypool or send coins) it will either be queried
			by a GUI prompt, or must first be entered with the walletpassphrase
			RPC command. This will change the wallet to "unlocked" state where the
			unencrypted master key is stored in memory (in the case of GUI, only for
			long enough to complete the requested operation, in RPC, for as long as
			is specified by the second parameter to walletpassphrase). The wallet is
			then locked (or can be manually locked using the walletlock RPC command)
			and the unencrypted master key is removed from memory.

			== Implementation details of wallet encryption ==

			When the wallet is locked, calls to sendtoaddress, sendfrom, sendmany,
			and keypoolrefill will return Error -13: "Error: Please enter the wallet
			passphrase with walletpassphrase first."

			When the wallet is unlocked, calls to walletpassphrase will fail.

			When a wallet is encrypted, the passphrase is required to top up the
			keypool, thus, if the passphrase is rarely entered, it is possible that
			keypool might run out. In this case, the default key will be used as the
			target for payouts for mining, and calls to getnewaddress and getaccount
			address will return an error. In order to prevent such cases, the keypool
			is automatically refilled when walletpassphrase is called with a correct
			passphrase and when topupkeypool is called (while the wallet is unlocked).
			Note that the keypool continues to be topped up on various occasions when
			a new key from pool is used and the wallet is unlocked (or unencrypted).

ThePiachu: Created page with "This is the wiki page describing the algorithm used for encrypting of the wallet.dat used in the original Bitcoin client."

2012-01-19T20:09:54Z

Created page with "This is the wiki page describing the algorithm used for encrypting of the wallet.dat used in the original Bitcoin client."

New page

This is the wiki page describing the algorithm used for encrypting of the wallet.dat used in the original Bitcoin client.

← Older revision		Revision as of 19:54, 6 April 2016
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	This ~~is the wiki~~ page ~~describing~~ the algorithm used for encrypting of the wallet.dat used in the original [[Bitcoin client]].		This page describes the algorithm used for encrypting the '''[[Wallet#Bitcoin_Qt\|wallet.dat]]''' file used in the original [[Bitcoin client]].

	Wallet encryption uses AES-256-CBC to encrypt only the private keys		Wallet encryption uses [https://en.wikipedia.org/wiki/AES-256 <span title="Advanced Encryption Standard with 256 bit key and Cipher Block Chaining">AES-256-CBC</span>] to encrypt only the private keys that are held in a wallet. The keys are encrypted with a master key
	that are held in a wallet. The keys are encrypted with a master key
	which is entirely random. This master key is then encrypted with		which is entirely random. This master key is then encrypted with
	AES-256-CBC with a key derived from the passphrase using ~~SHA512~~ and		AES-256-CBC with a key derived from the passphrase using [https://en.wikipedia.org/wiki/SHA-512 SHA-512] and
	OpenSSL's EVP_BytesToKey and a dynamic number of rounds determined by		OpenSSL's <code>EVP_BytesToKey</code> and a dynamic number of rounds determined by
	the speed of the machine which does the initial encryption (and is		the speed of the machine which does the initial encryption (and is
	updated based on the speed of a computer which does a subsequent		updated based on the speed of a computer which does a subsequent
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	the keystore stores the keys in encrypted form. When the passphrase		the keystore stores the keys in encrypted form. When the passphrase
	is required (to top up keypool or send coins) it will either be queried		is required (to top up keypool or send coins) it will either be queried
	by a GUI prompt, or must first be entered with the walletpassphrase		by a GUI prompt, or must first be entered with the <code>walletpassphrase</code>
	RPC command. This will change the wallet to "unlocked" state where the		[[Original_Bitcoin_client/API_calls_list#Full_list\|RPC command]]. This will change the wallet to "unlocked" state where the
	unencrypted master key is stored in memory (in the case of GUI, only for		unencrypted master key is stored in memory (in the case of GUI, only for
	long enough to complete the requested operation, in RPC, for as long as		long enough to complete the requested operation, in RPC, for as long as
	is specified by the second parameter to walletpassphrase). The wallet is		is specified by the second parameter to <code>walletpassphrase</code>). The wallet is
	then locked (or can be manually locked using the walletlock RPC command)		then locked (or can be manually locked using the <code>walletlock</code> RPC command)
	and the unencrypted master key is removed from memory.		and the unencrypted master key is removed from memory.

	== Implementation details of wallet encryption ==		== Implementation details of wallet encryption ==

	When the wallet is locked, calls to sendtoaddress, sendfrom, sendmany,		When the wallet is locked, calls to <code>sendtoaddress</code>, <code>sendfrom</code>, <code>sendmany</code>, and <code>keypoolrefill</code> will return ''Error -13: "Error: Please enter the wallet passphrase with walletpassphrase first."''
	and keypoolrefill will return Error -13: "Error: Please enter the wallet
	passphrase with walletpassphrase first."

	When the wallet is unlocked, calls to walletpassphrase will fail.		When the wallet is unlocked, calls to <code>walletpassphrase</code> will fail.

	When a wallet is encrypted, the passphrase is required to top up the		When a wallet is encrypted, the passphrase is required to top up the
	keypool, thus, if the passphrase is rarely entered, it is possible that		keypool, thus, if the passphrase is rarely entered, it is possible that
	keypool might run out. In this case, the default key will be used as the		keypool might run out. In this case, the default key will be used as the
	target for payouts for mining, and calls to getnewaddress and getaccount		target for payouts for mining, and calls to <code>getnewaddress</code> and <code>getaccount</code>
	address will return an error. In order to prevent such cases, the keypool		address will return an error. In order to prevent such cases, the keypool
	is automatically refilled when walletpassphrase is called with a correct		is automatically refilled when <code>walletpassphrase</code> is called with a correct
	passphrase and when topupkeypool is called (while the wallet is unlocked).		passphrase and when <code>topupkeypool</code> is called (while the wallet is unlocked).
	Note that the keypool continues to be topped up on various occasions when		Note that the keypool continues to be topped up on various occasions when
	a new key from pool is used and the wallet is unlocked (or unencrypted).		a new key from pool is used and the wallet is unlocked (or unencrypted).