Verify Authentication of Signed Documents: International Trade

International trade generates millions of contracts, letters of credit, bills of lading, and certificates of origin signed electronically each year across dozens of different jurisdictions. Yet, a study by the ICC (International Chamber of Commerce) published in 2024 reveals that 34% of cross-border commercial disputes involve contestations related to the authenticity or integrity of signed documents. Faced with this challenge, knowing how to verify the authenticity of a signed document in the international trade sector has become a strategic competency for legal, financial, and logistics departments. This article guides you through the technical mechanisms, international standards, and operational best practices to adopt in 2026.

Understanding the Authentication Mechanisms of Electronic Signatures

Before verifying the authenticity of a signed document, it is essential to understand what constitutes this authenticity from a technical perspective. A qualified electronic signature is based on three fundamental pillars: public key cryptography (PKI), digital certificates, and qualified time stamps.

Asymmetric Cryptography: Foundation of Verification

When a signatory applies an electronic signature, a cryptographic algorithm generates a unique fingerprint (hash) of the document. This fingerprint is encrypted with the signatory's private key, thereby creating the digital signature. To verify the authenticity of a signed document in international trade, the verifier uses the corresponding public key to decrypt this fingerprint and compare it to the recalculated hash of the received document. If the two match, two certainties emerge: the document has not been modified since signature (integrity), and only the holder of the private key could have signed (authenticity).

The most commonly used algorithms in 2026 remain RSA-2048, ECDSA, and for environments anticipating post-quantum cryptography, CRYSTALS-Dilithium, now standardized by NIST.

Digital Certificates: The Chain of Trust

The public key alone is insufficient. Its reliability depends on the digital certificate that accompanies it, issued by a recognized Certification Authority (CA). In the European context governed by the eIDAS regulation, only qualified trust service providers (QTSP) appearing on national trust lists (Trusted Lists published on the official EU portal) can issue qualified certificates.

For international trade, the complexity lies in mutual recognition between jurisdictions. A certificate issued by an American CA (example: DigiCert or Sectigo) may not benefit from the presumption of reliability granted to qualified eIDAS certificates in Europe. Conversely, a qualified eIDAS certificate is not automatically recognized as qualified in Japan or China, even though it will generally be accepted as legal evidence.

Qualified Time Stamping: Proof of Anteriority

The qualified time stamp (Qualified Time Stamp, QTS) constitutes the third pillar. It attests, in an enforceable manner, that the document existed in its signed form at a specific moment. In international commercial transactions, this proof of anteriority is crucial for resolving disputes related to contractual deadlines, dates of entry into force of guarantees, or delivery deadlines. The ETSI EN 319 421 standard governs the policies and procedures applicable to qualified time stamping authorities in the eIDAS space.

Practical Verification Methods in International Trade

Cryptographic theory must translate into concrete operational procedures. Here are the proven methods for verifying the authenticity of a signed document in the international trade sector.

Verification via Certified Signature Platforms

The most direct method is to use the original signature platform or a recognized third-party verification tool. Most SaaS electronic signature solutions compliant with eIDAS include a public verification portal or a verification API. Certyneo, for example, generates for each signed document a proof report (Audit Trail) downloadable in PDF/A, including the cryptographic fingerprint, the verified identity of the signatory, the qualified time stamp, and connection metadata.

For documents in PDF format, Adobe Acrobat Reader (version 11 and later) allows native verification of PDF/A signatures compliant with the PAdES standard (ETSI EN 319 132). It displays a validation banner indicating whether the signature is valid, whether the certificate is current, and whether the document was modified after signature.

Verification via Institutional Tools

The European Commission provides DSS (Digital Signature Services), a reference open-source tool for validating signatures in PAdES, XAdES, CAdES, and ASiC formats. Available online at ec.europa.eu/cefdigital/DSS, it automatically verifies the signature against European Trusted Lists.

For documents from third countries, several national authorities offer similar tools:

• The Adobe Approved Trust List (AATL) portal for globally recognized certificates

• The Trust List Browser of ETSI for European QTSPs

• The verification tool of the International Chamber of Commerce (ICC) for standardized commercial documents (Incoterms, electronic letters of credit eLCs)

Verification of Scanned Paper Documents with Electronic Signature

In international trade, many hybrid documents coexist: original paper documents bearing a scanned handwritten signature, with or without an electronic seal. In this case, verification requires a different approach:

1. Verification of the electronic seal (eSealing) affixed by the issuing organization on the digitized PDF

1. Control of the QR code or 2D barcode integrated, referring to a secure registry

1. Consultation of source registries (for certificates of origin, phytosanitary certificates, etc.) with the competent authorities (customs, chambers of commerce)

For electronic bills of lading (eBL), verification now often passes through specialized platforms such as BOLERO, essDOCS, or DCSA (Digital Container Shipping Association), which maintain registers of electronic property titles.

Specific Challenges in International Trade

Interoperability between Jurisdictions and Standards

The main challenge in verifying authenticity in international trade is the absence of a single worldwide standard. Three major frameworks coexist in 2026:

• Europe: eIDAS 2.0 Regulation (EU Regulation 2024/1183, applicable since May 2024), which extends mutual recognition and introduces the European Digital Identity Wallet (EUDIW)

• United States: ESIGN Act (2000) and UETA, with a technology-neutral approach but without a centralized trust list

• Asia-Pacific: APEC Framework (e-Commerce Steering Group), with highly heterogeneous levels of maturity across member countries

The UNCITRAL (United Nations Commission on International Trade Law) published in 2017 the Model Law on Electronic Transferable Documents and Signatures (MLETR), subsequently adopted by Bahrain, Singapore, the United Kingdom, the UAE, Germany, France (Ordinance No. 2024-872), and around a dozen other states. This law constitutes the foundation for a future worldwide standard for verifying electronic commercial documents.

The Language and Format Problem

A contract signed in Mandarin by a company based in Shanghai, using a certificate issued by a CA certified by the MIIT (Chinese Ministry of Industry and Information Technology), presents specific challenges. Neither European tools nor Adobe will automatically integrate this CA into their trust lists. Verification then requires:

• A request for a certificate of legalization (digital apostille if the country has joined the e-Apostille HCCH)

• Recourse to a bilateral trusted third party or an international chamber of commerce

• Use of a neutral verification platform accepted by both parties in the contract

Management of the Risk of Certificate Revocation

A document may have been signed with a valid certificate at the time of signature, but this certificate may have been subsequently revoked (compromise of the private key, change of signatory status, CA bankruptcy). Verification of authenticity must therefore include a check of the Certificate Revocation List (CRL) or an OCSP (Online Certificate Status Protocol) request at the time of verification.

The ETSI EN 319 102-1 standard requires that qualified signatures incorporate long-term validation evidence (LTV – Long Term Validation), allowing their validity to be verified even years after signature, regardless of the subsequent status of the certificate. Consult our comprehensive guide to eIDAS 2.0 regulation to deepen your understanding of these long-term trust mechanisms.

Implementing a Systematic Verification Procedure

Defining an Internal Verification Policy

Faced with the complexity of verifications in an international context, organizations must formalize an electronic signature verification policy (PVSE) integrated into their document management system. This policy must specify:

• The levels of signature accepted according to the nature of the document (SES, AES, or QES according to eIDAS)

• The signature formats recognized (PAdES, XAdES, CAdES, JAdES)

• The lists of CAs accepted for each partner geographic area

• Procedures for manual verification in out-of-standard cases

• Time periods for retaining proof of authenticity

Automating Verification via APIs

For organizations handling large volumes of international documents, manual verification is impractical. Modern signature platforms, including Certyneo, expose REST verification APIs allowing automation of authenticity control in document workflows (ERP, TMS, customs platforms). Such integration allows automatic verification of each document upon receipt, journalizing the result, and alerting in case of anomaly.

The Certyneo ROI calculator will allow you to estimate the productivity gains related to the automation of these verifications in your organization.

Training Operational Teams

Technology alone is insufficient. Customs, purchasing, legal, and financial teams must be trained to recognize warning signs: absence of proof report, non-cryptographic image signature, expired certificate, or certificate issued by an unrecognized CA. Annual training, coupled with documented procedures, significantly reduces the risk of accepting a fraudulent document. Our electronic signature glossary is a useful educational resource for training your teams on fundamental concepts.

Legal Framework Applicable to Verification of Authenticity in International Trade

The eIDAS Regulation and Its Evolution to eIDAS 2.0

In Europe, the legal foundation for verifying the authenticity of electronic signatures is the Regulation (EU) No. 910/2014 of the European Parliament and of the Council of 23 July 2014, known as the eIDAS regulation. Its Article 25 establishes the fundamental principle: a qualified electronic signature (QES) has the legal effect of a handwritten signature and enjoys a presumption of reliability. Article 32 specifies the requirements for validating qualified electronic signatures, referring to ETSI technical standards.

Since May 2024, the Regulation (EU) 2024/1183 (eIDAS 2.0) strengthens this framework by introducing the European Digital Identity Wallet (EUDIW), qualified electronic attribute attestations, and reinforced governance of QTSPs. It also extends the recognition of European qualified signatures to private sector entities.

French Law: Civil Code and Transposition

In French law, Articles 1366 and 1367 of the Civil Code (derived from Ordinance No. 2016-131) establish the probative value of electronic documents and electronic signatures. Article 1366 specifies that an electronic document has the same probative force as a document on paper support, provided that the person from whom it originates can be duly identified and that the document is established and retained in conditions designed to guarantee its integrity. Article 1367 defines the electronic signature and refers to the conditions set by decree (Decree No. 2017-1416 of 28 September 2017).

The MLETR and International Law

At the international level, the UNCITRAL Model Law on Electronic Transferable Documents and Signatures (MLETR, 2017) constitutes the reference for dematerialized commercial documents (bills of lading, bills of exchange, warehouse receipts). Its Article 10 requires that any system for controlling electronic transferable documents be reliable and appropriate to the context. France transposed it via Ordinance No. 2024-872 of 27 September 2024.

GDPR and Retention of Evidence

Verification of authenticity often involves the processing of personal data (signatory identity, behavioral biometric data). The Regulation (EU) 2016/679 (GDPR), particularly its Articles 5 (principles relating to processing), 17 (right to erasure), and 89 (archiving), governs the duration and methods of retaining verification evidence. In practice, signature audit reports must be retained for the duration of the statute of limitations applicable to the document concerned — up to 10 years for commercial instruments (Article L.110-4 of the Commercial Code) — which may conflict with the principle of data minimization.

Liability for Deficient Verification

The acceptance of a document whose signature has not been duly verified can engage the contractual and tort liability of the organization. In case of document fraud facilitated by a failure to verify, Articles 1240 and 1241 of the Civil Code can be invoked. Furthermore, the NIS2 Directive (EU) 2022/2555, transposed into French law by Act No. 2024-659 of 22 July 2024, imposes requirements on operators of vital importance and essential entities for information systems security including verification of the integrity of electronic exchanges.

Use Cases: Verification of Authenticity in International Trade

Scenario 1: A European Importer-Exporter Managing Several Hundred Contracts Annually

A European industrial SME specializing in the import-export of electronic components manages approximately 350 supplier contracts per year, with counterparties located in Southeast Asia, North America, and the Middle East. Before implementing a systematic verification procedure, its purchasing teams accepted electronically signed contracts without checking the validity of certificates or the presence of a qualified time stamp. Following a dispute with a Malaysian supplier contesting the date of a signed purchase order, the company suffered damages estimated at several tens of thousands of euros.

By deploying an automated verification API integrated into its ERP and adopting a policy requiring a minimum AES signature level for contracts under €50,000 and QES for higher amounts, the SME reduced by 90% the time to handle documentary disputes and eliminated incidents of accepting expired certificates. Return on investment was achieved in less than 8 months.

Scenario 2: A Customs Broker Managing Multicountry Electronic Declarations

A customs broker operating for a clientele of approximately 80 active shippers processes daily certificates of origin, packing lists, and commercial invoices signed electronically from 15 different countries. The diversity of formats (PAdES for European documents, XML signatures for Asian documents, hybrid paper-digital documents for some African countries) made manual verification extremely time-consuming — approximately 45 minutes per complex file.

By integrating a signature platform compliant with eIDAS with a multi-format verification module, the broker reduced this time to less than 5 minutes per file thanks to automated verification, representing an 89% reduction in processing time. Customs compliance (simplified clearance regime OEA) was also strengthened, reducing customs blockages by 40% on a comparable perimeter.

Scenario 3: An International Law Firm Specializing in Cross-Border Contract Law

A business law firm with approximately twenty partners and specialized in Europe-Asia cross-border M&A transactions is regularly faced with the need to verify the authenticity of documents signed by parties established in countries that do not recognize the eIDAS framework. For due diligence, each signed document (NDA, term sheets, agreement protocols) must be verified before being filed.

The firm adopted a two-level procedure: automated verification by platform for documents in standard digital format, and recourse to a recognized certifying third party (bilateral chamber of commerce or electronic notary) for documents from countries without an eIDAS equivalent. This approach made it possible to produce more robust due diligence reports, reducing requests for clarification from acquirers by 35% and shortening average transaction closing periods by 12 business days. To learn more about tools dedicated to legal professionals, consult our page dedicated to electronic signature for law firms.

Conclusion

Verifying the authenticity of a signed document in the international trade sector is a requirement that is simultaneously technical, legal, and organizational. The cryptographic mechanisms (PKI, digital certificates, qualified time stamping), regulatory frameworks (eIDAS 2.0, MLETR, Civil Code), and verification tools (DSS, validation APIs, audit trails) form a coherent ecosystem, provided it is understood in its entirety.

Organizations that automate and formalize their verification procedures drastically reduce their exposure to document fraud, accelerate their contracting cycles, and strengthen their regulatory compliance. Conversely, the absence of procedure exposes them to considerable financial and reputational risks.

Certyneo supports you in implementing a signature and verification infrastructure compliant with international trade requirements. Create your free account and discover how our platform simplifies the verification of authenticity of your cross-border documents starting today.