In this brief tutorial, I am going to provide an explanation on how to crack a wallet.dat file quickly using a technique called the Oracle Padding Attack. At present, there is a significant number of lost bitcoins, held in addresses commonly referred to as "Zombie addresses" or "Dormant addresses." These addresses have remained inactive for a decade or even longer, resulting in a lack of information about their owners and associated passwords. While numerous crypto enthusiasts have attempted to crack wallet.dat passwords, only a few have been fortunate enough to unearth these lost fortunes. The predominant method employed in such endeavors is the "Brute Force" technique, which involves systematically trying every possible combination of letters, characters, and numbers until the correct password is discovered. Although effective, this approach requires extensive trial and error, as well as substantial computational resources for faster results.
However, I will introduce an alternative method called the "Padding Oracle Attack" to crack a wallet.dat file faster. This technique is more intricate than brute force, yet it offers advantages in terms of time and resource efficiency. The Padding Oracle Attack leverages the concept of cryptographic message padding validation to decrypt ciphertext.
In cryptography, padding is frequently used to adjust the length of plaintext messages to align with the requirements of the underlying cryptographic algorithm. The attack relies on a "padding oracle," a source that provides information about whether a message is correctly padded or not. Padding oracle attacks are primarily associated with the decryption process in CBC mode, a commonly used block cipher mode. However, certain padding modes used in asymmetric algorithms, such as OAEP, may also be susceptible to padding oracle attacks.
To apply the Padding Oracle Attack to crack a Bitcoin Core wallet.dat file, we will treat the wallet.dat file itself as the "oracle." The attack will involve the utilization of a Python script I have written for this purpose, although I am currently developing a C version of the script with CUDA support for faster cracking. The C version with CUDA support is available in Beta mode and it has not been tested extensively yet.
Here are the requirements for the process:
- Python 3.x
- Required Python libraries: pycryptodome, pycrypto, hashlib, json, conda (optional for GPU support), and math
- GPU (recommended for faster password recovery)
Here is an outline of the steps involved in the cracking process:
Step 1: Initially, we need to determine the hash or "mkey" of the wallet.dat file. You can accomplish this by using the "hashfinder.py" script provided. Alternatively, you can utilize Pywallet to find the mkey.
Step 2: Once you have obtained the mkey, you will pass it along with other necessary parameters to the second script called "OPAttack.py." This script will then execute the padding oracle attack on the mkey, block by block. If a valid padding is discovered within a block, it will be appended and the passphrase will be saved byte by byte in the RAM. Once the script has completed the attack on the last four blocks, a file named "passphrase.txt" will be generated. This file contains the password for the wallet.dat file you are attempting to crack.
The padding oracle attack offers an effective and proven method to crack wallet.dat files without resorting to brute force. By exploiting the vulnerability in the padding, this technique significantly reduces the time required for the cracking process. For a comprehensive tutorial on how to crack any wallet.dat file using the padding oracle attack, please refer to the accompanying video. If you are interested in obtaining the beta version of the script written in C with CUDA support, feel free to contact me at
Email: [email protected]