1. Executive Summary
Casa Hacker is a Brazilian non-profit civil society organisation dedicated to STEAM education and social innovation. As part of its institutional strengthening programme, Casa Hacker has deployed a self-hosted instance of Documenso Community Edition as an electronic signature and document digitisation platform.
This case study is shared with the Documenso community as a practical reference for organisations seeking to build a legally valid document-signing infrastructure using open-source technology.
Main conclusion: When configured with an ICP-Brazil A1 certificate, RFC 3161 timestamps and the appropriate preprocessing workflow, Documenso CE produces qualified electronic signatures — the highest legal tier in Brazilian legislation — at a fraction of the cost of proprietary alternatives.2. About Casa Hacker
Casa Hacker is a non-profit association based in São Paulo, Brazil. Its mission is to make STEAM education and social innovation accessible to all. The organisation operates several digital services of public interest, including a Moodle-based learning platform (Mão na Massa), an anonymous whistleblowing channel (Abre o Jogo, based on GlobaLeaks) and a research infrastructure used by civil society partners across Brazil.
Casa Hacker’s infrastructure philosophy is built on self-sufficiency: whenever feasible, services are self-hosted on Brazilian soil using open-source software. This approach reduces dependence on proprietary SaaS providers, lowers operating costs and ensures full control over sensitive data — a critical requirement when handling documents related to public-interest activities.
3. The Challenge
Civil society organisations in Brazil face a specific tension. On the one hand, they are legally required to maintain documentation with a high degree of authenticity — funder contracts, employment agreements, declarations to public bodies. On the other hand, they typically operate with severely limited budgets. Commercial electronic signature platforms frequently charge per document or per user, making them prohibitive at scale.
Beyond cost, organisations acting in the public interest must be able to demonstrate, at any future point, that a document was signed by specific parties at a specific moment. This requirement corresponds directly to the legal concept of a qualified electronic signature in Brazilian legislation.
Casa Hacker evaluated several platforms before choosing Documenso CE. The decisive factors were the combination of open-source transparency, self-hosting capability and — crucially — native support for external signing certificates, which allowed the organisation to directly integrate its own ICP-Brazil A1 certificate into the signing workflow.
4. Brazilian Legal Framework for Electronic Signatures and Document Digitisation
4.1 Three-Tier Classification
Brazilian legislation recognises three levels of electronic signature, each with distinct probative weight. The framework is established primarily by Law 14,063/2020.
4.2 Relevant Legislation
Provisional Measure 2,200-2/2001
This foundational instrument created ICP-Brazil (Infraestrutura de Chaves Públicas Brasileira), the national public key infrastructure. Article 10, §1 establishes that documents signed with ICP-Brazil certificates enjoy a legal presumption of authenticity equivalent to that attributed to handwritten signatures by Article 219 of the Civil Code. The Provisional Measure remains in force by constitutional provision and has never been repealed.
Law 12,682/2012 — Document Digitisation
Article 1 regulates the digitisation, electronic storage and reproduction of public and private documents. The law defines digitisation as the faithful conversion of a physical document into a digital format. Digitised documents under this law can replace the paper original for all legal purposes, provided the requirements for authenticity and integrity are met.
Law 13,874/2019 — Economic Freedom Law
This law updated Law 12,682/2012 to reinforce the legal validity of digitised documents and extended this validity to private sector digitisation workflows, reducing bureaucratic demands for companies and organisations.
Decree 10,278/2020 — Technical Standards for Digitisation
This decree regulates Law 12,682/2012 by defining specific technical standards that a digitisation process must meet for the resulting document to possess the same probative value as the physical original. The main requirements include: minimum resolution of 300 DPI, PDF/A-2B format, mandatory metadata fields and a qualified electronic signature (ICP-Brazil) certifying the author of the digitisation and the integrity of the document.
For documents involving only private parties, Article 6 permits any agreed method of proof. In the absence of prior agreement, the ICP-Brazil standard applies by default.
STJ — REsp 2,159,442 (December 2024)
The Superior Court of Justice (STJ), the highest instance for non-constitutional matters in Brazil, ruled unanimously that advanced electronic signatures possess valid legal force even when the certifying entity is not accredited by ICP-Brazil. Justice Nancy Andrighi noted that the advanced signature is equivalent to signature recognition by similarity, whilst the qualified signature is equivalent to signature recognition by authenticity. Both are legally valid; the difference lies in the burden of proof required to challenge them.
Practical implication: Documents signed by Documenso CE with a valid ICP-Brazil A1 certificate receive the highest legal protection available in Brazilian legislation. Documents signed without ICP-Brazil, but with adequate identity verification, remain legally valid, although they may require additional proof if contested.
5. Documenso Community Edition
Documenso is an open-source, self-hostable electronic document signature platform positioned as a transparency-driven alternative to DocuSign and similar proprietary services. The Community Edition is free and available at github.com/documenso/documenso under the AGPL-3.0 licence.
Key capabilities relevant to Brazilian legal compliance:
- External signing certificates: Native support for PKCS#12 (.p12) certificates, allowing the direct use of ICP-Brazil credentials
- RFC 3161 timestamps: Integration with timestamp authorities for Long-Term Validation (LTV), independently certifying the exact moment of signing
- Immutable audit trail: Every action on every document is logged and preserved
- PDF-based workflow: Documents are standard PDFs verifiable by any PDF reader or the ITI/VALIDAR portal
- Self-hosted architecture: Data never leaves the organisation’s own infrastructure
- Multi-recipient signing: Configurable signing order with support for sequential and parallel workflows
- Access control: Public registration can be disabled for organisation-restricted deployment
6. Casa Hacker Deployment Configuration
6.1 Infrastructure Overview
Casa Hacker operates Documenso CE on a self-hosted Linux server located in São Paulo, Brazil. The entire technology stack runs in Docker containers with Traefik as a reverse proxy with TLS termination. SSL certificates are obtained automatically via Let’s Encrypt.
The deployment uses a dedicated PostgreSQL database and connects to an external SMTP relay for notification emails. User registration is disabled (NEXT_PUBLIC_DISABLE_SIGNUP=true), restricting access to authorised organisational users.
6.2 ICP-Brazil Certificate Configuration
The signing certificate is an ICP-Brazil A1 organisational certificate (e-CNPJ type) issued by AC VALID BRASIL v5, a certifying authority accredited within the ICP-Brazil chain. The certificate holder is the organisation itself rather than a specific individual, making it suitable for institutional document signing.
The certificate is stored as a PKCS#12 (.p12) file mounted directly into the Documenso container. The signing passphrase is supplied via an environment variable and is never stored in plain text in any versioned configuration file.
Relevant configuration parameters:
NEXT_PRIVATE_SIGNING_LOCAL_FILE_PATH — path to the .p12 file inside the containerNEXT_PRIVATE_SIGNING_PASSPHRASE — certificate passphrase (managed via secrets)NEXT_PRIVATE_SIGNING_TIMESTAMP_URLS — dual TSA endpoints (DigiCert and Sectigo)
Operational note: The certificate’s validity period is tracked in the organisation’s operational calendar. Renewal must be initiated at least 30 days prior to expiry to avoid interruption of signing capabilities.
6.3 RFC 3161 Timestamp Integration
Two RFC 3161 Timestamp Authority endpoints are configured: one operated by DigiCert and another by Sectigo. This dual-TSA configuration ensures redundancy — if one authority is temporarily unavailable at the time of signing, the other is used automatically.
The timestamp cryptographically links the document hash to an exact moment in time via a trusted third-party clock. This is the mechanism behind Long-Term Validation (LTV): even after the signing certificate expires, the timestamp proves that the signature was performed whilst the certificate was valid, preserving the legal validity of the document indefinitely.
This configuration resolves the “Indeterminate” status displayed on the ITI/VALIDAR portal for documents without timestamps. Documents signed by this infrastructure display the “Valid” status on ITI/VALIDAR, the official validation tool of the Brazilian government.
7. Operational Use Cases
7.1 Native Digital Document Signing Workflow
For documents created directly in digital format — contracts, agreements, declarations — the workflow follows these steps:
The resulting document is a standard PDF containing an embedded qualified electronic signature, verifiable by Adobe Acrobat Reader, any PDF validator and the ITI/VALIDAR portal (iti.gov.br/validar).
7.2 Physical Document Digitisation Workflow
For physical documents that must be preserved in digital format with full legal equivalence to the original — minutes, signed agreements, certificates — the following workflow meets the requirements of Decree 10,278/2020:
Note: Stirling PDF (Ultra-Lite version, without OCR) performs the conversion to PDF/A-2B and basic metadata editing without the need for any external service. Both Documenso and Stirling PDF operate as self-hosted containers on the same server, keeping the entire workflow within the organisation’s controlled infrastructure.
7.3 Scope and Limitations
This configuration is suitable for:
- Contracts and agreements with private parties and civil society partners
- HR documentation (employment terms, volunteering agreements)
- Declarations and authorisations
- Organisational governance documents (meeting minutes, board decisions)
- Compliance and due diligence forms (KYC/KYS, supplier compliance)
- Documents submitted to public entities that accept advanced or qualified signatures
The following use cases are out of scope for this configuration and require additional infrastructure or individual qualified certificates:
- Real estate transfer and registration — requires individual ICP-Brazil certificates and notary involvement
- Electronic invoices (NF-e) — governed by SEFAZ’s own infrastructure
- Judicial proceedings — subject to specific regulations of each court
8. Legal Compliance Summary
8.1 Signature Compliance
8.2 Digitisation Compliance
9. Cost Analysis
9.1 Total Cost (Annual)
All costs are based on actual prices from the first quarter of 2026. USD values use an indicative exchange rate of R$ 5.75/USD.
Documenso-specific annual TC (ICP certificate + attributable fraction of hosting): approximately R$ 600–R$ 1,000 per year (USD 104–174).
9.2 Comparison with Commercial Alternatives
The following comparison uses public pricing from the first quarter of 2025 for equivalent functionality — qualified electronic signatures with ICP-Brazil compliance in Brazil.
Conclusion: For a civil society organisation signing between 100 and 500 documents per year, Documenso CE with an ICP-Brazil A1 certificate delivers qualified-level legal protection at 10 to 20 times lower cost than equivalent commercial SaaS platforms — whilst keeping all data under the organisation’s direct control.
10. Security and Operational Considerations
10.1 Infrastructure Security
The Documenso instance is protected by multiple independent layers of security:
- Network-level protection: CrowdSec IDS/IPS with community threat intelligence, operating at both the Traefik reverse proxy layer (HTTP) and the host iptables layer (all protocols, including SSH)
- Transport security: TLS 1.2/1.3 enforced at the Traefik layer; automatic certificate renewal via ACME/Let’s Encrypt
- Access control: User registration is disabled; only pre-provisioned accounts can access the administration interface
- Network isolation: Each service stack operates on its own Docker network; Documenso exposes only its designated port to the Traefik network
- Backup: Encrypted nightly backups to Azure Blob Storage across three geographic regions (Europe, Americas, Africa)
10.2 Certificate Lifecycle Management
The ICP-Brasil A1 certificate is a time-bound credential that requires active lifecycle management:
- Certificates are valid for one year from issuance; renewal must be initiated at least 30 days in advance
- Renewal requires presenting updated organisational documents to the Registration Authority and paying an annual fee
- Following renewal, the new .p12 file must be deployed to the server and the Documenso container restarted
- The expiration date must be tracked in the organisation’s operational calendar with automated reminders
Note on the ICP-Brasil certificate roadmap: The ICP-Brasil governance body has announced the transition of A1/A3 certificates for legal entities towards an Electronic Seal model, with completion expected by 2029. Organisations should monitor ITI communications at iti.gov.br for migration guidance. Documenso’s certificate-agnostic architecture (PKCS#12 standard) ensures compatibility with the new Electronic Seal format when available.
11. Conclusion
Documenso Community Edition, when properly configured with an ICP-Brasil A1 organisational certificate and RFC 3161 timestamp authorities, delivers a document signing and digitisation infrastructure that fully complies with the highest tier of Brazilian electronic signature legislation.
For organisations like Casa Hacker, which handle documents of legal consequence — contracts with public and private partners, compliance records, organisational governance — this configuration provides:
- Qualified electronic signatures with a legal presumption of authenticity
- Digitisation workflows that produce records with legal equivalence to physical originals
- Long-term archival validity through RFC 3161 timestamps
- Complete data sovereignty — no document leaves the organisation’s infrastructure
- Cost efficiency — the primary recurring cost is the ICP-Brasil certificate (~R$ 300–400/year)
This case study demonstrates that an open-source document signing infrastructure, when deployed thoughtfully, can meet or exceed the legal standards achieved by commercial alternatives at a fraction of the cost — making it a genuinely viable option for civil society organisations, NGOs, academic institutions and small businesses operating in Brazil.
12. Acknowledgements
Casa Hacker thanks the Documenso team and the open-source community for building a platform that prioritises transparency, self-sufficiency and legal rigor. The decision to support external signing certificates — rather than locking organisations into a proprietary certificate infrastructure — was the decisive feature that made this deployment feasible.
This white paper is offered to the Documenso community as a contribution to the shared body of knowledge on legally compliant deployments in Brazil and potentially in other jurisdictions with mature public key infrastructure frameworks.
References
- Provisional Measure No. 2.200-2/2001 — planalto.gov.br
- Law No. 12.682/2012 — planalto.gov.br
- Law No. 13.874/2019 (Economic Freedom Law) — planalto.gov.br
- Law No. 14.063/2020 — planalto.gov.br
- Decree No. 10.278/2020 — planalto.gov.br
- STJ — REsp 2,159,442 (December 2024) — stj.jus.br
- ITI/VALIDAR — gov.br/iti
- Documenso CE — github.com/documenso/documenso
- ICP-Brasil — iti.gov.br