How Microsoft stores and shares your encryption keys

The idea that your data is safe on your laptop as long as you are the only one with the password is an illusion. Recent news confirms what privacy experts have long feared: Microsoft hands over BitLocker encryption keys to U.S. law enforcement agencies like the FBI. While the key is stored in Microsoft’s cloud vault, the actual data remains on your hard drive. This means authorities need physical access to your device to unlock the data. For the average home user in Europe, this risk is abstract. But for European professionals crossing the U.S. border with a work laptop, this fundamentally changes the rules of the game.

The BitLocker illusion: Why 'local' isn't truly local

The core issue lies in the convenience of modern technology. BitLocker, Microsoft’s standard encryption software, encrypts your hard drive to prevent unauthorized access. However, a recent criminal case in Guam revealed that the FBI obtained recovery keys for three laptops directly from Microsoft via a court order. How is this possible? When you log into Windows with a Microsoft account, your recovery key is often automatically uploaded to Microsoft’s servers as a backup in case you forget your password. Legally, this means Microsoft owns the key and must surrender it under the U.S. CLOUD Act.

Experts like Matt Green of Johns Hopkins University warn that, unlike Apple or Google, Microsoft does not encrypt these keys in a way that makes them unreadable even to the company itself. The result is a fundamental breach of data sovereignty: you may think the key is in your pocket, but a copy resides in Redmond, Washington. As long as your laptop remains physically in Europe, the risk of seizure is low. But once you set foot on U.S. soil, physical access by authorities becomes a real possibility.

Border control: Where your rights end

The legal reality at the U.S. border is sobering for Europeans. Under the so-called "Border Search Exception," U.S. Customs and Border Protection (CBP) can search electronic devices without a warrant. Here, a crucial distinction arises between U.S. citizens and foreign visitors. An American who refuses to unlock their laptop may lose their device but cannot be denied entry. As an EU citizen, you do not have this protection. If you refuse to cooperate, you can be denied entry and sent back on the next flight home.

The danger here is not an advanced remote hack but simple physical coercion. If you don’t provide your password, authorities can seize your device. With the device in hand and a request to Microsoft for the BitLocker key, your data becomes accessible. This renders the debate over "secure" local storage irrelevant in a border scenario. Physical control of the device, combined with legal control over Microsoft, creates a situation where your data is effectively public to the U.S. government.

GDPR nightmare: business consequences of seizure

For European companies, this is not just a privacy issue but a direct legal risk. European privacy law (GDPR) clashes head-on with U.S. surveillance laws. Suppose you travel with a laptop containing customer data, personnel files, or intellectual property. If U.S. customs copies this data—which they are legally permitted to do—your company technically faces a data breach. Under GDPR, such a breach, where unauthorized parties access personal data, must often be reported to the supervisory authority, such as the Dutch Data Protection Authority, within 72 hours.

This puts companies in an impossible bind. The U.S. CLOUD Act forces tech companies to comply, while GDPR compels European companies to maintain confidentiality and protection. Even if your data is stored in a European data center, it falls under U.S. jurisdiction if the provider is American. Recent revelations about BitLocker underscore that "compliance" on paper means little if the technical infrastructure is fundamentally compromised by foreign laws. Companies must recognize that sending a laptop with sensitive data across the border is equivalent to exporting that data to an insecure legal jurisdiction.

The 'gold standard' protocol: How to travel safely

Given the legal and technical risks, the advice for business travelers is clear: do not carry data. Security experts and law firms recommend a strict "clean" protocol for travel to the U.S. The safest method is to use a "burner laptop"—a wiped or empty laptop with only the operating system and essential software, containing no locally stored files. Once at your destination, connect to your company network via a secure VPN. Work entirely in the cloud or via a remote desktop, without downloading files to the local drive.

At border control, the device’s status is critical. Shut down the laptop completely (not sleep mode), which forces full encryption activation and clears the RAM. Enable airplane mode before shutting down to prevent accidental connections upon restart. If customs forces you to unlock the device, you can do so without concern—there is nothing on it. This avoids entry denial while keeping your company’s secrets safe in Europe.

The European path forward: Digital sovereignty

This incident with Microsoft and the FBI is not an isolated case but a symptom of a larger problem: the lack of European digital autonomy. As long as we rely on U.S. tech giants for our basic infrastructure, our data remains subject to U.S. whims. However, there is light at the end of the tunnel. The EU is actively working on legislation like the Data Act and the Cloud Sovereignty Framework to regain control. These initiatives aim to make it easier to switch providers and demand transparency about where data is stored and who can access it.

For conscious organizations, now is the time to explore alternatives. Choose cloud providers and software vendors under European jurisdiction that guarantee "key sovereignty"—where you, and only you, own the keys. Until then, your best defense at the border is not advanced encryption but an empty hard drive.