TL;DR
Yes, a KeePass file can theoretically be cracked offline given enough computing power and time. However, cracking is extremely difficult with strong passwords or master keys. The feasibility depends entirely on the password strength and available resources.
Understanding KeePass Security
KeePass uses robust encryption algorithms (typically AES-256) to protect your database. The security relies almost entirely on the strength of your master password or key file. When you unlock a KeePass database, it’s essentially decrypting data using this secret.
How Offline Cracking Works
- Brute-Force Attacks: This is the most common method. The attacker tries every possible combination of characters until they find the correct password. This is incredibly slow for strong passwords.
- Dictionary Attacks: Attackers use a list of commonly used passwords (a dictionary) and try them against the KeePass file.
- Keyfile Cracking: If you use a key file, attackers can attempt to find or guess its location and then try brute-forcing it. This is less common as key files are usually stored securely by the user.
Steps Involved in an Offline Crack Attempt
- Obtain the KeePass File: The attacker needs access to your .kdbx file. This could be through malware, theft, or social engineering.
- Choose a Cracking Tool: Several tools can attempt to crack KeePass files offline. Popular options include:
- Hashcat
- John the Ripper
- Configure the Cracking Tool: This involves specifying the KeePass file, the encryption algorithm (usually automatically detected), and the attack mode.
hashcat -m 3200 filename.kdbx ?a?a?a?a?a?a(This example uses Hashcat with a simple brute-force attempt using six lowercase letters.)
- Run the Attack: The cracking tool will start trying different password combinations. This can take hours, days, weeks, or even years depending on password complexity and hardware.
- Evaluate Results: If the attack is successful, the tool will reveal the master password or key file.
Factors Affecting Cracking Time
- Password Length: Longer passwords are exponentially harder to crack. A 12-character password takes far longer than an 8-character one.
- Password Complexity: Using a mix of uppercase and lowercase letters, numbers, and symbols significantly increases cracking time.
- Hardware: GPUs (Graphics Processing Units) are much faster at brute-force attacks than CPUs. More powerful hardware speeds up the process.
- Attack Mode: Brute-force is slower than dictionary attacks if the password is in the dictionary.
Protecting Your KeePass Database
- Use a Strong Master Password: At least 16 characters, with a mix of uppercase and lowercase letters, numbers, and symbols. Consider using a passphrase instead of a traditional password.
- Enable Key Files: Using a key file in addition to a strong master password adds an extra layer of security. Store the key file securely (e.g., on a USB drive kept in a safe place).
- Use Two-Factor Authentication (if possible): Some KeePass plugins offer two-factor authentication options.
- Keep Your Software Updated: Ensure you’re using the latest version of KeePass to benefit from security patches.
- Be Wary of Phishing and Malware: Protect your computer from threats that could steal your KeePass file or master password.
Real-World Feasibility
For a well-protected KeePass database (strong password, key file, updated software), offline cracking is generally impractical for most attackers. The time and resources required are too high. However, if your password is weak or you’ve been compromised by malware, the risk increases significantly.