HomeWinBuzzer NewsBitLocker's Encryption Compromised in Under a Minute Using $10 Microcontroller

BitLocker’s Encryption Compromised in Under a Minute Using $10 Microcontroller

Security researcher cracks BitLocker encryption in 43 seconds using a cheap Raspberry Pi, exposing vulnerability in external TPM modules.

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Security researcher stacksmashing has successfully intercepted BitLocker encryption keys, utilizing a low-cost Raspberry Pi Pico, challenging the perceived robustness of 's method. A video demonstration of the method, which undermines the Trusted Platform Module (TPM)-dependent security, reveals the attack execution time as merely 43 seconds.

The Attack Vector: Hijacking TPM Communications

Stacksmashing's approach capitalizes on the vulnerabilities of external TPM modules that interface with the central processing unit (CPU) over the Low Pin Count (LPC) bus, a communication pathway that is, notably, unencrypted at startup. These modules are intended to safeguard sensitive information, including Platform Configuration Registers and the Volume Master Key—both critical to BitLocker's encryption efficacy.

By tapping into the LPC bus during the system's boot-up sequence using a Raspberry Pi Pico attached to an LPC connector, which is present on some older motherboards, stacksmashing could capture the binary data transmitted to the TPM. The extracted information allowed reconstruction of the Volume Master Key necessary to decrypt the protected drive.

Mitigation and Microsoft's Response

While Microsoft acknowledges the potential for such attacks, it downplays the risk, citing the need for sophisticated tools and significant physical access time. Despite the brevity of the demonstrated attack, Microsoft recommends establishing a PIN via Group Policy to enhance security.

The described technique targets systems with external TPMs, with many modern devices possessing fTPM—TPM functionality integrated directly within the CPU, which is not susceptible to the same attack method. The revelation of this vulnerability emphasizes the importance of additional security measures and challenges the reliability of existing protections in TPM-dependent encryption solutions.

SourceMicrosoft
Luke Jones
Luke Jones
Luke has been writing about all things tech for more than five years. He is following Microsoft closely to bring you the latest news about Windows, Office, Azure, Skype, HoloLens and all the rest of their products.

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