English

BitCracker: BitLocker meets GPUs

Cryptography and Security 2019-01-08 v1

Abstract

BitLocker is a full-disk encryption feature available in recent Windows versions. It is designed to protect data by providing encryption for entire volumes and it makes use of a number of different authentication methods. In this paper we present a solution, named BitCracker, to attempt the decryption, by means of a dictionary attack, of memory units encrypted by BitLocker with a user supplied password or the recovery password. To that purpose, we resort to GPU (Graphics Processing Units) that are, by now, widely used as general-purpose coprocessors in high performance computing applications. BitLocker decryption process requires the computation of a very large number of SHA- 256 hashes and also AES, so we propose a very fast solution, highly tuned for Nvidia GPU, for both of them. We analyze the performance of our CUDA implementation on several Nvidia GPUs and we carry out a comparison of our SHA-256 hash with the Hashcat password cracker tool. Finally, we present our OpenCL version, recently released as a plugin of the John The Ripper tool.

Keywords

Cite

@article{arxiv.1901.01337,
  title  = {BitCracker: BitLocker meets GPUs},
  author = {Elena Agostini and Massimo Bernaschi},
  journal= {arXiv preprint arXiv:1901.01337},
  year   = {2019}
}
R2 v1 2026-06-23T07:03:39.584Z