 KeePass Help Center
|
 KeePass Home |
 Downloads |
 Translations |
 Plugins |
 Donate  Help Center Home |
 Forums |
 Awards |
 Links |
 |
Ane | Wa Yan PatchedDetails about components of a master key. |
- Master Password
- Key File
- Windows User Account
- For Administrators: Specifying Minimum Properties of Master Keys
Your KeePass database file is encrypted using a master key. This master key can consist of multiple components: a master password, a key file and/or a key that is protected using the current Windows user account.
For opening a database file, all components of the master key are required.
If you forget/lose any of the master key components (or forget the composition), all data stored in the database is lost. There is no backdoor and no universal key that can open your database.
Master Password
If you use a master password, you only have to remember one password or passphrase (which should be good!) to open your database.
KeePass features a protection against brute-force and dictionary attacks; see the security help page for details.
Key File
A key file is a file that contains a key (and possibly additional data, e.g. a hash that allows to verify the integrity of the key). The file extension typically is 'keyx' or 'key'.
A key file must not be modified, otherwise you cannot open your database anymore. If you want to use a different key file, open the dialog for changing the master key (via 'File' → 'Change Master Key') and create/select the new key file.
Two-factor protection. A key file is something that you must have in order to be able to open the database (in contrast to a master password, which you must know). If you use both a key file and a master password, you have a two-factor protection: possession and knowledge.
Location. As mentioned above, the idea of a key file is that you have something. If an attacker obtains both your database file and your key file, then the key file provides no protection. Therefore, the two files must be stored in different locations. For example, you could store the key file on a separate USB stick.
Hiding the location. The key file content must be kept secret, not its location (file path/name). Trying to hide the key file (e.g. by storing it among a thousand other files, in the hope that an attacker does not know which file is the correct one) typically does not increase the security, because it is easy to find out the correct file (e.g. by inspecting the last access times of files, lists of recently used files of the operating system, file system auditing logs, anti-virus software logs, etc.).
KeePass has an option for remembering the paths of key files, which is turned on by default; turning it off typically just decreases the usability without increasing the security. This option only affects KeePass itself (i.e. turning it off does not prevent the operating system or other software from remembering the paths). If you only want to prevent a key file from appearing in the recently used files list of Windows (which does not really affect the security) after selecting it in KeePass, consider turning on the option for entering the master key on a secure desktop (KeePass will then show a simpler key file selection dialog that does not add the file to the recently used files list of Windows).
Backup. You should create a backup of your key file (onto an independent data storage device). If your key file is an XML file (which is the default), you can also create a backup on paper (KeePass 2.x provides a command for printing a key file backup in the menu 'File' → 'Print'). In any case, the backup should be stored in a secure location, where only you and possibly a few other people that you trust have access to. More details about backing up a key file can be found in the ABP FAQ.
Formats. KeePass supports the following key file formats:
- XML (recommended, default).
There is an XML format for key files.
KeePass 2.x uses this format by default, i.e. when creating a key file
in the master key dialog, an XML key file is created.
The syntax and the semantics of the XML format allow to detect certain
corruptions (especially such caused by faulty hardware or transfer problems),
and a hash (in XML key files version 2.0 or higher) allows to
verify the integrity of the key.
This format is resistant to most encoding and new-line character changes
(which is useful for instance when the user is opening and saving the
key file or when transferring it from/to a server).
Such a key file can be printed (as a backup on paper),
and comments can be added in the file (with the usual XML syntax:
<!-- ... -->). It is the most flexible format; new features can be added easily in the future. - 32 bytes. If the key file contains exactly 32 bytes, these are used as a 256-bit cryptographic key. This format requires the least disk space.
- Hexadecimal. If the key file contains exactly 64 hexadecimal characters (0-9 and A-F, in UTF-8/ASCII encoding, one line, no spaces), these are decoded to a 256-bit cryptographic key.
- Hashed. If a key file does not match any of the formats above, its content is hashed using a cryptographic hash function in order to build a key (typically a 256-bit key with SHA-256). This allows to use arbitrary files as key files.
Reuse. You can use one key file for multiple database files. This can be convenient, but please keep in mind that when an attacker obtains your key file, you have to change the master keys of all database files protected with this key file.
Windows User Account
Be very careful with using this option. If your Windows user account
gets deleted, you won't be able to open your KeePass database anymore.
Also, when using this option at home and your computer breaks (hard disk
damaged), it is not
enough to just create a new Windows account on the new installation with the
same name and password;
you need to copy the complete account (i.e. SID, ...). This is not
a simple task, so if you don't know how to do this, it is highly recommended
that you don't enable this option.
Detailed instructions how to recover a Windows user account can be found here:
'Recover Windows User Account Credentials'
(a short technical tutorial can be found in a Microsoft TechNet article:
'How to recover a Vault corrupted by lost DPAPI keys').You can change the password of the Windows user account freely; this does not affect the KeePass database. Note that changing the password (e.g. a user using the Control Panel or pressing Ctrl+Alt+Delete and selecting 'Change Password') and resetting it to a new one (e.g. an administrator using a
NET USER <User> <NewPassword>
command) are two different things.
After changing your password, you can still open your KeePass database.
When resetting the password to a new one, access usually is not possible
anymore (because the user's DPAPI keys are lost), but there are exceptions
(for example when the user is in a domain, Windows can retrieve the user's DPAPI keys
from a domain controller, or a home user can use a previously created
Password Reset Disk).
Details can be found in the MSDN article
'Windows Data Protection' and in the support article
'How to troubleshoot the Data Protection API (DPAPI)'.If you decide to use this option, it is highly recommended not to rely on it exclusively, but to additionally use one of the other two options (password or key file).
Instead of backing up the Windows user account, you can alternatively create an unencrypted backup of the key using the 'Windows User Account Backup and Restore Utility'. As such a backup is not encrypted, it must be stored in a secure location.
Protection using user accounts is unsupported on Windows 98 / ME.
For Administrators: Specifying Minimum Properties of Master Keys
Administrators can specify a minimum length and/or the minimum estimated quality that master passwords must have in order to be accepted. You can tell KeePass to check these two minimum requirements by adding/editing appropriate definitions in the INI/XML configuration file.
KeeMasterPasswordMinLength key can contain
the minimum master password length in characters. For example, by specifying
KeeMasterPasswordMinLength=10, KeePass will only accept
master passwords that have at least 10 characters.The value of the
KeeMasterPasswordMinQuality key can contain
the minimum estimated quality in bits that master passwords must have. For example,
by specifying KeeMasterPasswordMinQuality=64, only master passwords
with an estimated quality of at least 64 bits will be accepted.
Ane | Wa Yan Patched
Yan nodded. “I’m not asking for the old promises. I’m asking to help carry the things that need carrying.”
Ane took to patching differently now. She kept the visible stitches she’d once been ashamed of, and she learned to patch other things with the same honesty: promises with a margin for human failure, apologies that came with actions attached, small surprises stitched into dull afternoons. Yan, for his part, left little markers of his travels—shells threaded into a curtain, a clock that chimed once an hour because he liked the idea of time marked by kindness rather than by rush.
Ane woke to the sound of rain tapping the eaves like someone anxious to be let in. The cottage smelled of wet wood and the faint, sweet tang of tea left on the stove. She pulled the patchwork blanket tighter around her shoulders and peered out the window: the lane bent away into grey, and the town’s lanterns glowed like cautious fireflies. ane wa yan patched
The phrase made her smile. There was honesty in it. It meant she was not whole in the way she had been before, but she was usable, cared for, kept. There was dignity in being mended openly, the way a well-loved garment shows its stitches.
And on the bench by the river, the compass caught the sun now and then, sparking like a promise neither of them took for granted. Yan nodded
Her pulse quickened. Noon at the old mill meant the river where they’d once raced willow branches, where Yan had taught her to skip stones, where he’d once promised to bring the moon if the moon could be carried. She tucked the note into her pocket and stepped out, the rain easing to a mist. On the lane, greetings came—little nods, quiet smiles—as if the town itself suspected the day might seam into something different.
At the mill, the wheel creaked its slow, familiar song. The water made a steady, forgiving rhythm—no clocks, no deadlines, only the patient turning. Yan stood beneath the sagging awning, taller than she remembered, hair flecked with silver that caught the light. He wore a coat patched at the elbow with a square of green cloth that matched the dress she had once mended for him in jest. She kept the visible stitches she’d once been
Yan. The name settled in her chest like a held breath. He had been gone longer than anyone remembered, a boy who used to skip stones on the river and whistle tunelessly while he fixed clocks. People said he’d left to see the world, to chase a dream that didn’t fit this little town. Others whispered that he’d left because of Ane—because their stubbornness had clashed, because he’d been afraid to promise and she refused not to hope.
