Level33 - A Secure Transfer Solution Compliant with French Cybersecurity Standards

Level33 is a secure file transfer solution that enables the reliable exchange of sensitive data between various entities (users, companies, partners) while ensuring confidentiality, integrity, and availability of information. Designed to meet security needs in professional and regulated environments, it relies on modern and robust protocols to protect files during sending, receiving, and temporary storage.


Key Benefits of Level33

  1. Ease of Implementation: The service is easy to install and configure (via automation tools like Ansible), significantly reducing the time and effort required for deployment.
  2. Ease of Use: The intuitive interface allows all users, even those without advanced technical expertise, to securely transfer files.
  3. Reduced Exposure to Cyber Threats: By limiting access points to the Information System (IS) and securing end-to-end transfers, Level33 reduces the potential attack surface in line with ANSSI recommendations for interconnecting information systems with the Internet.
  4. Regulatory and Normative Compliance: The service meets French standards requirements, including those defined in II901, IGI 1300, and ANSSI recommendations on the administration and interconnection of information systems.
  5. Auditability and Traceability: Detailed audit logs, compliant with II901 and Security Incident Detection Service Provider (PDIS) requirements, ensure complete transparency of operations.
  6. Integration with Existing Infrastructure: Compatible with standard infrastructure tools (centralized authentication, identity management, centralized logs).

Use Cases

  1. Interconnection with Sensitive Information Systems: The solution’s architecture allows the implementation of interconnection gateways between information systems with different security levels or classifications (as per II901).
  2. Regulated Sectors: Compliance with the requirements of financial, healthcare, public administration, or industrial sectors, adhering to GDPR, II901, and IGI 1300.
  3. Inter-Enterprise Collaboration: Secure sharing between partners while ensuring the confidentiality of sensitive data.
  4. Remote Work: Secure transfers for decentralized teams outside the traditional IS perimeters.

Level33 is a turnkey solution aligned with the strict requirements of French standards, enabling organizations to secure their exchanges while meeting increasing compliance and cybersecurity demands. Leveraging ANSSI, II901, IGI 1300, and SecNumCloud frameworks, it provides optimal protection against modern threats while enhancing efficiency and ease of use.


Typical Architectures for a Secure Interconnection Gateway with the Level33 Solution

A typical secure interconnection architecture for file transfers between two information systems with different security levels relies on several key principles to ensure the integrity, confidentiality, and traceability of exchanges.

At the heart of the proposed architecture is the Level33 gateway, which strictly controls data flows between environments and performs protocol-breaking and inspection functions.

This gateway includes analysis mechanisms to inspect transferred files and ensure they do not contain malicious content, as well as a logging system to record all transactions. The generated logs can be forwarded to an analysis platform (e.g., SIEM) via a standard collection protocol (e.g., SYSLOG protocol - RFC 5424 or 5425). Thus, the monitoring team (e.g., the Security Operations Center or SOC) can respond to reported security incidents. A demilitarized zone (DMZ) can also be implemented to isolate the exposed component of the gateway.

Typical Usage

The Level33 solution is based on the secure SFTP transfer protocol to encrypt data in transit. Finally, strict segregation is maintained to prevent direct access between systems with different security levels, applying access rules based on the principle of least privilege and robust authentication procedures. This architecture enables efficient exchanges while meeting security requirements.


Typical Architectures for Interconnecting a Class 1 Sensitive IS with a Class 0 IS

In the context of a Class 1 information system authorized at the “Restricted Distribution” classification level (DR - per Instruction Interministerial 901), the interconnection architecture for file transfers with a Class 0 information system is strictly controlled. This architecture must ensure the absence of direct communication between systems through protocol-breaking, inspection, monitoring, and filtering mechanisms using qualified products (where possible, such as firewalls and IDS sensors).

Thus, an exchange gateway must be implemented. This gateway, governed by a qualified filtering solution, will host the Level33 file transfer solution.

Data flows can be constrained using a diode positioned between the exposed component of the solution and the internal component.

Interconnection of a Class 1 Sensitive IS with a Class 0 IS

All flows must be under constant surveillance using a qualified detection probe (e.g., IDS).

Finally, security logs (firewall, IDS probe, and Level33 solution logs) must be forwarded to the analysis platform (e.g., SIEM) via a standard collection protocol (e.g., SYSLOG protocol - RFC 5424 or 5425). Thus, the monitoring team (e.g., the Security Operations Center or SOC) can respond to reported security incidents.


Compliance with Standards and Recommendations

Level33 is designed to meet the main directives of French cybersecurity standards and guidelines, including:

1. Compliance with Instruction Interministérielle 901 (II901)

Instruction Interministérielle 901 prescribes measures for systems handling sensitive or strategic data.

Audit and Traceability: Level33 maintains comprehensive audit logs that document actions related to file transfers, access, and modifications. In accordance with II901, Article 4.5, audit logs must provide complete traceability of sensitive actions, including access, transfers, and modifications of files. Logs are produced in a format interoperable with SIEM (Security Information and Event Management) solutions.

File Lifecycle Management: Article 3.6.3 of II901 specifies that sensitive data must be managed with strict retention policies. Level33 integrates automatic file deletion mechanisms for expired data, aligned with this requirement.

2. Compliance with Instruction Générale Interministérielle 1300 (IGI 1300)

Instruction Générale Interministérielle 1300 governs systems handling classified information, imposing specific measures for access control and the protection of sensitive data.

Granular Access Control: IGI 1300, Chapter 2.5, mandates that access rights to classified information be limited to the strict minimum (principle of least privilege). Level33 incorporates granular permission management (viewing, modification, deletion), compliant with these directives.

Isolation and Segmentation: Article 3.3 of IGI 1300 requires the implementation of segmentation zones for systems handling sensitive information. Level33 uses a DMZ architecture to isolate components exposed to the internet from internal systems, in line with this requirement.

Automatic File Expiration: Article 4.6 of IGI 1300 requires that sensitive data be deleted once its use is complete. Level33 automates file lifecycle management to meet this requirement.

3. Compliance with ANSSI Recommendations

Recommendations concerning the interconnection of an IS to the internet and the secure administration of information systems are implemented through several features:

Data Encryption: Section 3.3 (R7) of ANSSI’s Recommendations on the Interconnection of an Information System to the Internet mandates the use of robust protocols (TLS 1.2 minimum, AES-256 for storage) to ensure the confidentiality of sensitive data. Level33 complies with these recommendations by securing transfers with TLS/SSL.

Protocol Break Mechanism: A protocol break gateway isolates internal systems from the internet, minimizing the risk of cyberattack propagation. Section 2.3.1 (R3) of ANSSI’s Recommendations on the Interconnection of an Information System to the Internet advises the implementation of a protocol break mechanism to protect internal systems from uncontrolled network flows. Level33 integrates a gateway with protocol break functionality and DPI (Deep Packet Inspection) (Sections 2.2.1 and 2.2.2, R2 and R3) to detect attacks.

Network Segmentation: The guide Recommendations on the Interconnection of an Information System to the Internet (R6, Section 2.2.2) recommends the use of a DMZ to isolate services exposed to the internet. Level33 adheres to this recommendation by hosting external access points in a DMZ while keeping critical systems in internal zones.

4. ANSSI Qualifications (e.g., SecNumCloud or PDIS)

SecNumCloud Compliance: The architecture meets SecNumCloud requirements, particularly regarding the security of cloud infrastructures and protection against advanced threats. The framework mandates the implementation of gateways for inbound and outbound filtering (12.10.c and 12.14.a). Level33’s solution:

  • Automatically expunges data that could compromise client (i.e., commanditaire) confidentiality.
  • Provides inspection capabilities for transferred files, with quarantine options.
  • Generates activity logs.
  • Automatically verifies the authenticity and safety of transferred files using signatures (e.g., hash or PGP signature) and antivirus analysis.

PDIS Requirements: The framework for Security Incident Detection Service Providers (i.e., PDIS) mandates a specific architecture for the detection service’s information system. It requires the implementation of at least three exchange zones for file transfers, dedicated to administrators, operators, and clients (i.e., commanditaires) – see Requirements IV.3.8.b and IV.3.9.j.

Level33 was designed from the ground up to comply with recommendations outlined in the chapter “Exchange System of the Technical Note NT_ADMIN” of ANSSI (i.e., see the document Recommendations on the Secure Administration of Information Systems).


Specific References

For further details on the cited requirements, refer to the following texts and guides:

  1. II901: Instruction Interministérielle No. 901 of July 23, 2014, on the protection of sensitive information systems.
  2. IGI 1300: Instruction Générale Interministérielle No. 1300 on the protection of national defense secrets (July 2021 version).
  3. ANSSI, Recommendations on the Interconnection of an Information System to the Internet: Version 3.0, published by ANSSI in June 2020.
  4. ANSSI, Recommendations on the Secure Administration of Information Systems: Version 3.0, published by ANSSI in May 2021.
  5. SecNumCloud: Certification framework for cloud service providers, published by ANSSI.
  6. PDIS: Security Incident Detection Service Providers, as outlined in the French Military Planning Act (LPM).