How European Law Firms Can Preserve Legal Privilege and Client Confidentiality Against Foreign Government Demands
Legal professional privilege is the foundation of the lawyer-client relationship across every European jurisdiction. Whether expressed as Anwaltsgeheimnis under Germany's Federal Lawyers' Act and Criminal Code, secret professionnel under France's Law of 31 December 1971, or legal professional privilege in common law Ireland, the principle is the same: clients must be able to communicate with their lawyers in absolute confidence that those communications will remain protected from disclosure.
This foundational protection is now structurally undermined by a technology decision that most law firms made without fully considering its implications. When a European law firm uses file sharing platforms, email systems, or collaboration tools operated by US-headquartered providers, every privileged communication and confidential client document that passes through those platforms falls within the potential reach of the US CLOUD Act. The provider can be compelled to produce data regardless of where it is stored, without notifying the law firm or its clients, and without the involvement of any European judicial process.
This guide examines how European law firms can preserve legal privilege and client confidentiality through architectural decisions that place privileged communications beyond the reach of foreign government demands.
Executive Summary
Main Idea: European law firms are bound by professional secrecy obligations that are criminally enforceable in many jurisdictions—yet when lawyers exchange privileged communications through US-operated platforms, they create a technical pathway that allows foreign government access without any European judicial authorization. The data sovereignty question for law firms is not abstract; it is a question of whether the firm's technology infrastructure matches the legal obligations it has undertaken.
Why You Should Care: The CCBE's February 2025 cloud computing guidelines explicitly warn lawyers to verify that cloud providers are not subject to jurisdictions with long-arm legislation obliging data handover to non-EU authorities, and 65% of UK firms have already experienced a cyber incident. Clients in regulated industries are increasingly requiring data governance assurances from outside counsel, and firms that cannot demonstrate sovereign architecture for privileged communications risk losing mandates to competitors who can.
5 Key Takeaways
- Professional secrecy is a legal obligation, not a preference, and criminal penalties apply in many jurisdictions. Under Germany's §203 StGB, unauthorized disclosure of client information is a criminal offense. France treats professional secrecy as a matter of public order. These obligations extend to the technological choices lawyers make for storing and transmitting privileged communications.
- The CLOUD Act creates a structural bypass of European privilege protections. When a law firm uses communication platforms from US-headquartered providers, those providers can be compelled to produce data under US law, without European judicial authorization, and without notifying the firm. Customer-controlled encryption is the only technical measure that eliminates this exposure.
- The 2025 Council of Europe Convention on the Profession of Lawyer raises the baseline for privilege protection. Adopted in March 2025 and signed by 18 countries, the Convention strengthens lawyers' rights to confidential client communications. Article 7 explicitly addresses state surveillance of lawyer-client exchanges, establishing a binding international framework that technology choices must support.
- Cross-border matters create compounding privilege vulnerabilities. When a Magic Circle firm coordinates a multinational M&A transaction, privileged documents flow between offices in London, Frankfurt, Paris, and Amsterdam through shared platforms. Each data movement through a non-sovereign platform multiplies the jurisdictional exposure of every privileged document in that matter.
- Sophisticated clients now audit outside counsel's data infrastructure. Financial institutions under DORA, pharmaceutical companies protecting clinical trial IP, and defense contractors subject to CMMC requirements increasingly evaluate their law firms' platform sovereignty as part of vendor assessment. Firms without sovereign architecture risk losing mandates in the most regulated and highest-value sectors.
The Legal Framework for Professional Secrecy Across Europe
National Privilege Doctrines Share a Common Purpose That Technology Choices Must Respect
European legal professional privilege operates through diverse national mechanisms that share a common objective: ensuring that clients can communicate with their lawyers in confidence. In Germany, professional secrecy rests on dual foundations—Section 43a(2) of the Federal Lawyers' Act (BRAO) imposes a positive duty to observe professional secrecy, and Section 203(1)(3) of the Criminal Code (StGB) makes unauthorized disclosure a criminal offense punishable by imprisonment up to one year. The 2017 reform of §203 StGB expanded the circle of persons to whom secrets may be disclosed (including IT service providers), but imposed criminal liability on those third parties and required lawyers to bind them to confidentiality agreements.
France Treats Professional Secrecy as a Matter of Public Order With No Technological Exception
France treats professional secrecy with particular force. Article 66-5 of the Law of 31 December 1971 covers all communications between lawyer and client, between lawyers, and all documents in the case file. Article 2 of the National Internal Rules classifies professional secrecy as a matter of public order. The Conseil National des Barreaux has stated that lawyers must be "particularly exemplary" with respect to professional secrecy in digital communications, describing it as a "keystone principle" that technological evolution does not diminish. Similar enforceable obligations exist across the EU—Italy's Article 622 of the Criminal Code, Poland's Advocates Act, the Netherlands' Supreme Court case law, and Austria's Rechtsanwaltsordnung Section 9 all establish professional secrecy as a binding legal obligation with enforceable consequences.
The 2025 Council of Europe Convention and CCBE Guidelines Create New Binding Standards for Digital Privilege
The Council of Europe Convention for the Protection of the Profession of Lawyer, adopted unanimously on March 12, 2025, is the first binding international treaty dedicated to protecting lawyers. Signed by 18 countries including France, Germany, the Netherlands, Italy, Ireland, and Poland, Article 7 specifically strengthens lawyers' rights to communicate with clients without state surveillance, with a dedicated monitoring mechanism (GRAVO) overseeing implementation.
The CCBE's updated cloud computing guidelines, published in February 2025, explicitly state that lawyers should verify that cloud computing service providers are not subject to jurisdictions with long-arm legislation obliging them to hand over European lawyers' data to non-EU national authorities. The guidelines require lawyers to treat professional secrecy and GDPR obligations as primary considerations when selecting cloud services. The European Court of Justice has further reinforced lawyers' special status—in the context of the DAC6 directive, the Court acknowledged that lawyers' professional secrecy requires stronger protections than those afforded to other professions.
How Foreign Government Access Laws Undermine Privilege
The CLOUD Act Reaches Every US-Operated Platform Regardless of Where Data Is Stored
The US CLOUD Act (Clarifying Lawful Overseas Use of Data Act), enacted in 2018, amends the Stored Communications Act to make explicit that US service providers must preserve and produce data they control regardless of where it is stored. When a European law firm uses Microsoft 365, Google Workspace, or any other platform operated by a US-headquartered company for file sharing and email, that firm's privileged communications fall within the CLOUD Act's reach.
CLOUD Act Demands Operate Entirely Through the US Legal System, Bypassing European Judicial Process
A CLOUD Act demand does not require the involvement of any European court, does not require notification to the law firm or its clients, and operates entirely through the US legal system. While the CLOUD Act includes a comity analysis mechanism, its practical effectiveness is questionable. As the Groupe d'Études Géopolitiques analysis notes, it is far from clear that US courts would consider failure to comply with EU rules protecting professional confidentiality as sufficiently serious to release a provider from its CLOUD Act obligations. The recent Ontario Court decision ordering OVHcloud's Canadian subsidiary to produce data stored in France, the UK, and Australia—despite OVH's argument that disclosure would breach French law—demonstrates that courts in one jurisdiction are increasingly willing to compel production of data held by corporate subsidiaries in another, regardless of local protections.
FISA 702 and the Patriot Act Create Additional Foreign Access Pathways Beyond the CLOUD Act
The CLOUD Act is not the only US law reaching European law firm data. FISA Section 702 authorizes surveillance of non-US persons for foreign intelligence purposes, and the Patriot Act expanded government access to stored communications in national security contexts. Together, these laws create multiple pathways through which US authorities can access data held by US providers without European legal process. The EU's Digital Sovereignty Declaration of November 2025 reflects growing political recognition of this structural dependency, reinforcing the professional obligation to evaluate whether technology infrastructure aligns with European sovereignty objectives.
Where Legal Privilege Is Most at Risk
Client Communications Seeking Legal Advice Contain the Information Privilege Exists to Protect
The highest-sensitivity data flow in any law firm is the exchange of legal advice between lawyer and client. When a corporate client emails its outside counsel seeking advice on a potential antitrust investigation, the email contains precisely the type of information that privilege is designed to protect: the client's candid assessment of its situation, potentially damaging facts it needs legal guidance on, and strategic considerations about how to respond. If this email flows through a US-operated platform, the very communication that privilege exists to protect is technically accessible under US law.
For cross-border firms, this problem compounds. A partner in Frankfurt advising a German client on EU competition matters may need to consult with colleagues in London, Paris, and Brussels. Each internal communication carries privileged analysis through the firm's email and document sharing systems. If those systems are operated by a US provider, every internal exchange multiplies the jurisdictional exposure—and no privilege analysis can resolve a vulnerability that is architectural rather than legal.
Work Product and Litigation Strategy Are Precisely What Opposing Parties and Foreign Regulators Seek
Legal work product—including litigation strategies, draft pleadings, and case assessments—receives strong protection in jurisdictions that distinguish between advice privilege and litigation privilege. But this protection is meaningless if work product is stored on platforms where foreign authorities can compel production. A competition law firm's assessment of a client's market position, prepared for a merger notification, contains strategic intelligence valuable to regulators, competitors, and political actors. A criminal defense firm's exposure analysis contains precisely what prosecutors seek. When this work product resides on platforms subject to the CLOUD Act, it is potentially accessible to US authorities who may share information with European counterparts through mutual legal assistance channels or informal intelligence cooperation.
M&A Data Rooms Concentrate Deal Intelligence That Is Uniquely Vulnerable on Cloud Platforms
Cross-border M&A transactions generate enormous volumes of privileged and commercially sensitive documentation. Virtual data rooms contain target company financial records, IP portfolios, and legal analyses. Transaction correspondence carries privileged advice about valuation, deal structure, and negotiation strategy. When these data rooms and communication channels run on US-operated platforms, the entire deal file is jurisdictionally exposed. The 2023 Proskauer Rose breach—where a threat actor accessed 184,000 files containing privileged financial and legal documents through an unsecured Azure cloud server—demonstrates the catastrophic consequences when concentrated deal intelligence on cloud platforms is compromised.
Regulatory Investigations Involving Concurrent US and European Enforcement Create the Sharpest Privilege Exposure
When a European company faces a regulatory investigation, outside counsel typically conducts an internal review generating interview memoranda, document analyses, and strategic assessments that are among the most sensitive materials in any matter. When the platforms through which these materials flow are subject to foreign government access, the privilege analysis becomes academic. A US government agency investigating conduct that also involves European regulatory scrutiny could access privileged materials through a CLOUD Act demand, bypassing the European privilege analysis entirely. The risk is particularly acute in matters involving concurrent US and European enforcement proceedings in antitrust, sanctions, and anti-corruption.
Building Sovereign Architecture for Privileged Communications
Customer-Controlled Encryption Is the Only Measure That Renders Foreign Legal Compulsion Technically Irrelevant
The single most important architectural decision for protecting legal privilege in the digital environment is implementing customer-controlled encryption where the law firm generates, manages, and retains encryption keys in its own hardware security module (HSM) or key management system. Under this model, the platform provider processes encrypted data but cannot decrypt it. When a CLOUD Act demand arrives, the provider cannot produce readable privileged communications because it does not possess the decryption keys.
This directly addresses the structural problem that the CCBE's 2025 cloud computing guidelines identify. Customer-controlled encryption renders the provider's legal obligations under foreign law operationally irrelevant because compliance is technically impossible. For law firms operating under Germany's §203 StGB framework, this architecture aligns with the 2017 reform's requirements—when the provider cannot access decrypted data, the risk of unauthorized disclosure through the provider is eliminated at the technical level, providing stronger protection than contractual confidentiality alone.
Single-Tenant European Deployment Ensures Privileged Communications Are Never Commingled With Other Organisations' Data
Law firm data should reside on dedicated infrastructure serving only that firm, not on shared multi-tenant platforms where privileged communications coexist with data from other organizations under different jurisdictional arrangements. For international law firms with offices across multiple European jurisdictions, single-tenant deployment can serve the entire firm while maintaining sovereignty—a single sovereign platform instance serving all offices, with the firm retaining encryption key control regardless of which office originates a communication.
Comprehensive Audit Trails Satisfy Professional Accountability Requirements and Client Governance Demands Simultaneously
Audit logging that records every access, modification, and transfer of privileged communications provides evidence for client inquiries about data handling, supports GDPR accountability requirements, enables detection of unauthorized access, and creates documentary evidence that bar associations and courts may require if privilege claims are challenged. For firms handling matters subject to regulatory scrutiny, comprehensive audit trails also demonstrate governance practices to regulators and clients who increasingly expect demonstrable accountability over privileged information.
The Client Pressure Driving Law Firm Sovereignty
DORA, EHDS, and CMMC Requirements Are Flowing Through to Outside Counsel Vendor Assessments
European law firms are increasingly facing data governance requirements from their most sophisticated clients. Financial institutions subject to DORA must document third-party ICT risks across their entire vendor ecosystem, and outside law firms that handle privileged banking data are part of that ecosystem. Pharmaceutical companies protecting clinical trial IP and patient data under the EHDS require assurance that their legal advisors' platforms do not create access pathways that their own infrastructure has been designed to eliminate. Defense contractors subject to CMMC requirements must evaluate whether their counsel's data handling meets controlled unclassified information protection standards.
Panel Review Processes Now Include Technology and Cybersecurity Questionnaires as Standard Practice
This is not a future development. Large institutional clients already include technology and cybersecurity questionnaires in their panel review processes. When a firm cannot demonstrate that its communication platforms provide sovereign architecture with customer-controlled encryption, it becomes a harder sell against competitors that can. In the highest-value practice areas—M&A, competition, regulatory investigations, and international arbitration—the ability to demonstrate data sovereignty is becoming a differentiation factor alongside legal expertise and industry knowledge.
Sovereign Architecture Addresses Both the Cybersecurity Threat and the Sovereignty Threat Simultaneously
Law firms are among the most targeted organizations for cyberattacks. According to the Law Society of England and Wales, 65% of UK firms have experienced a cyber incident, and the first half of 2024 saw 21 law firm breaches reported in the US. The cybersecurity threat and the sovereignty threat are related but distinct: cybersecurity addresses unauthorized criminal access, while sovereignty addresses legally authorized foreign government access. A firm that implements strong cybersecurity but uses US-operated platforms has addressed one threat while leaving the other structurally unresolved. Sovereign architecture with customer-controlled encryption addresses both simultaneously—even if platform infrastructure is compromised, encrypted data cannot be read without the firm's keys.
Practical Implementation for Different Firm Types
International Firms Should Deploy a Single Sovereign Platform Serving All Offices Under Unified Key Control
International firms with offices across multiple European jurisdictions should deploy a single sovereign communication platform serving the entire firm, with customer-controlled encryption where the firm's own key management infrastructure ensures no external party can access privileged content. The platform should unify email protection, file sharing, and managed file transfer under consistent encryption and governance policies—ensuring that a privileged document flowing between Frankfurt and Paris receives the same sovereign protection as one that never leaves a single office.
Boutique and Mid-Market Firms Require Sovereign Architecture Without In-House Security Expertise
Smaller boutique and mid-market firms handle matters that are equally sensitive. A three-partner criminal defense firm may hold information more personally consequential for its clients than anything in a Magic Circle firm's files. These firms should prioritize a platform that provides sovereign architecture without requiring in-house security expertise, with managed deployment options and integrated communication channels that reduce operational complexity while maintaining the same encryption and access control standards as larger deployments.
Kiteworks Helps European Law Firms Preserve Legal Privilege and Client Confidentiality
European law firms face a structural conflict between their professional secrecy obligations and their technology infrastructure choices. Customer-controlled encryption resolves this conflict architecturally: when the platform provider cannot decrypt privileged communications, foreign government access through that provider becomes technically impossible rather than legally prohibited—a materially stronger protection. The CCBE's 2025 guidelines, the Council of Europe Convention, and the client governance requirements flowing from DORA and EHDS all point in the same direction, and sovereign architecture satisfies all of them through a single deployment decision.
The Kiteworks Private Data Network provides law firms with the sovereign communication infrastructure they need to protect privileged communications and client confidentiality from foreign government demands. Kiteworks operates on a customer-managed encryption model where the law firm generates and retains encryption keys in its own key management system. Kiteworks cannot access decrypted privileged communications and cannot comply with foreign government demands to produce readable client data because it does not possess the keys.
Kiteworks deploys as a single-tenant instance on dedicated European infrastructure, ensuring that privileged communications are not commingled with data from other organizations. Policy-enforced geofencing prevents privileged data from leaving designated geographic boundaries, and comprehensive audit logging provides the accountability evidence that professional secrecy obligations, GDPR supervisory authorities, and client governance requirements demand.
The platform unifies secure file sharing for deal documentation and matter collaboration, email protection for privileged lawyer-client communications, managed file transfer for large document productions and regulatory submissions, and secure web forms for client data collection under a single zero trust governance framework. This enables law firms to protect all privileged communication channels through one platform with consistent encryption, access controls, and audit evidence that aligns with the CCBE's 2025 cloud computing guidelines and national professional secrecy obligations.
To learn more about preserving legal privilege and client confidentiality through sovereign architecture, schedule a custom demo today.
Frequently Asked Questions
The CLOUD Act compels US-headquartered platform providers to produce data under US legal authority regardless of where that data is stored, without requiring European judicial involvement or notification to the law firm. When a European law firm uses a US-operated email or file sharing platform, privileged communications residing on that platform are technically accessible to US authorities through the provider—bypassing European privilege protections that require judicial authorization under national law. Customer-controlled encryption where the law firm retains exclusive key control is the only measure that renders this access technically impossible, because the provider cannot decrypt what it does not hold keys for.
The CCBE’s February 2025 guidelines explicitly require lawyers to verify that cloud computing service providers are not subject to jurisdictions with long-arm legislation obliging data handover to non-EU national authorities—a direct reference to laws like the CLOUD Act. The guidelines further require lawyers to consider professional secrecy and GDPR as primary factors when selecting cloud services, assess security measures and encryption capabilities, and ensure that data storage arrangements do not compromise confidentiality obligations. Lawyers who select platforms operated by US-headquartered providers without addressing these concerns face potential professional liability under both the CCBE framework and national bar regulations.
Section 203 of Germany’s Criminal Code makes unauthorized disclosure of client information by a lawyer a criminal offense. The 2017 reform expanded the circle of persons to whom secrets may be disclosed to include IT service providers who collaborate in professional activities, but imposed criminal liability on those providers for unauthorized disclosure and required lawyers to bind them to confidentiality agreements. When a US-operated platform provider is compelled under the CLOUD Act to produce data, it faces a direct conflict between US legal obligations and German criminal law. Customer-controlled encryption resolves this conflict architecturally by ensuring the provider never possesses the ability to disclose decrypted client data.
The Convention, adopted unanimously in March 2025 and signed by 18 countries, is the first binding international treaty dedicated to protecting lawyers and includes specific provisions on confidentiality and professional secrecy. Article 7 strengthens lawyers’ rights to communicate with clients without state surveillance, establishing a binding international standard that reinforces the obligation to protect lawyer-client communications at the technological level. Firms that use platforms enabling foreign government access to privileged communications operate in tension with both the Convention’s purpose and the national protections it reinforces.
Cross-border matters involving multiple European jurisdictions subject law firms to overlapping privilege doctrines that may offer different scope and strength of protection—Germany’s Anwaltsgeheimnis protects the lawyer against state intervention, France’s secret professionnel is classified as public order, and common law privilege attaches to the communication itself. When privileged documents flow between offices in different jurisdictions, the firm must meet the highest applicable standard. Deploying a single sovereign communication platform with customer-controlled encryption across all offices eliminates the technology infrastructure as a variable in the privilege analysis, ensuring that the firm’s architectural protections meet or exceed every applicable national standard.
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