Verify Authenticity 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 challenges relating 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 skill for legal, financial and logistics management. This article guides you through the technical mechanisms, international standards and operational best practices to adopt in 2026.

Understanding Electronic Signature Authentication Mechanisms

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

Asymmetric Cryptography: The Foundation of Verification

When a signatory applies their electronic signature, a cryptographic algorithm generates a unique fingerprint (hash) of the document. This fingerprint is encrypted with the signatory's private key, thus 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 signing (integrity), and only the holder of the private key could have signed it (authenticity).

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

Digital Certificates: The Chain of Trust

The public key alone is not sufficient. Its reliability depends on the digital certificate that accompanies it, issued by a recognised Certification Authority (CA). In the European context governed by the eIDAS regulation, only qualified trust service providers (QTSP) listed on national trust lists (Trusted Lists published on the official EU portal) may issue qualified certificates.

For international trade, the complexity lies in mutual recognition between jurisdictions. A certificate issued by a US 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 recognised as qualified in Japan or China, even though it will generally be accepted as legal evidence.

Qualified Time-Stamping: Proof of Precedence

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

Practical Methods of Verification in International Trade

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

Verification via Certified Signature Platforms

The most direct method consists of using the original signing platform or a recognised third-party verification tool. Most SaaS electronic signature solutions compliant with eIDAS integrate a public verification portal or a verification API. Certyneo, for example, generates for each signed document a downloadable proof report (Audit Trail) in PDF/A format, including the cryptographic fingerprint, verified signatory identity, 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, if the certificate is in force and if the document has been modified after signing.

Verification via Institutional Tools

The European Commission provides DSS (Digital Signature Services), a reference open-source tool allowing validation of 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 certificates recognised worldwide

• The Trust List Browser from ETSI for European QTSPs

• The verification tool from the International Chamber of Commerce (ICC) for standardised 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 digitised 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 body on the scanned PDF

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

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

For electronic bills of lading (eBL), verification now often takes place through specialised platforms such as BOLERO, essDOCS or DCSA (Digital Container Shipping Association), which maintain registers of electronic title of ownership.

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 technologically neutral approach but without a centralised trust list

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

UNCITRAL (United Nations Commission on International Commercial Law) published in 2017 the Model Law on Transferable Electronic Documents and Signatures (MLETR), since adopted by Bahrain, Singapore, the United Kingdom, the UAE, Germany, France (Ordinance No. 2024-872) and about ten other States. This law constitutes the foundation of a future worldwide standard for the verification of electronic commercial documents.

The Issue of Languages and Formats

A contract signed in Mandarin by a company based in Shanghai, using a certificate issued by a CA certified by the MIIT (China's 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:

• The request for a legalisation certificate (digital apostille if the country has joined the HCCH e-Apostille)

• 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

Managing the Risk of Certificate Revocation

A document may have been signed with a valid certificate at the time of signing, but then this certificate may have been revoked subsequently (compromise of the private key, change in signatory status, failure of the CA). 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 signing, independent of the subsequent status of the certificate. Please see 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 verification in an international context, organisations must formalise an electronic signature verification policy (PVSE) integrated into their document management system. This policy must specify:

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

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

• The lists of CAs accepted for each geographic partner zone

• Procedures for manual verification of non-standard cases

• Deadlines for retention of authenticity evidence

Automating Verification via APIs

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

Certyneo's ROI calculator will allow you to estimate the productivity gains associated with the automation of these verifications in your organisation.

Training Operational Teams

Technology alone is not enough. Customs, procurement, legal and financial teams must be trained to recognise warning signs: absence of proof report, non-cryptographic signature image, expired certificate or issued by an unrecognised CA. Annual training, coupled with documented procedures, significantly reduces the risk of accepting a fraudulent document. Our electronic signature glossary provides a useful educational resource for training your teams in the 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 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, Regulation (EU) 2024/1183 (eIDAS 2.0) strengthens this framework by introducing the European Digital Identity Wallet (EUDIW), qualified electronic attestations of attributes and enhanced governance of QTSPs. It also extends recognition of European qualified signatures to private sector entities.

French Law: Civil Code and Transposition

Under French law, Articles 1366 and 1367 of the Civil Code (stemming from Ordinance No. 2016-131) establish the probative value of electronic writing and electronic signature. Article 1366 specifies that electronic writing has the same probative force as writing on paper medium, provided that the person from whom it emanates can be duly identified and the writing is established and preserved under conditions designed to guarantee its integrity. Article 1367 defines electronic signature and refers to the conditions set by decree (Decree No. 2017-1416 of 28 September 2017).

MLETR and International Law

At the international level, the UNCITRAL Model Law on Transferable Electronic Documents and Signatures (MLETR, 2017) is the reference for dematerialised commercial documents (bills of lading, bills of exchange, warehouse receipts). Its Article 10 requires that any system for controlling transferable electronic 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, behavioural biometric data). Regulation (EU) 2016/679 (GDPR), in particular its Articles 5 (principles relating to processing), 17 (right to erasure) and 89 (archiving), governs the duration and manner of retention of verification evidence. In practice, signature audit reports must be retained for the duration of the applicable limitation period for the document concerned — up to 10 years for acts of commerce (Article L.110-4 of the Commercial Code) — which may come into tension with the principle of data minimisation.

Liability in Case of Deficient Verification

Acceptance of a document whose signature has not been duly verified may engage the contractual and tortious liability of the organisation. In case of document fraud facilitated by a lack of verification, Articles 1240 and 1241 of the Civil Code may be invoked. Moreover, the NIS2 Directive (EU) 2022/2555, transposed in France by Law No. 2024-659 of 22 July 2024, imposes on operators of vital importance and essential entities requirements for the security of information systems including verification of the integrity of electronic exchanges.

Use Cases: Verification of Authenticity in International Trade

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

A European SME specialised 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 procurement teams accepted electronically signed contracts without checking the validity of certificates or the presence of qualified time-stamping. Following a dispute with a Malaysian supplier contesting the date of an electronically signed purchase order, the company suffered a loss estimated at several tens of thousands of euros.

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

Scenario 2: A Customs Agent Managing Multicountry Electronic Declarations

A customs agent operating for a clientele of approximately 80 active data controllers 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 an eIDAS-compliant electronic signature platform with a multi-format verification module, the agent reduced this timeframe to less than 5 minutes per file thanks to automated verification, representing an 89% reduction in processing time. Customs compliance (simplified customs clearance regime OEA) was also strengthened, reducing customs delays by 40% on a comparable perimeter.

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

A business law firm with twenty partners specialising in Europe-Asia cross-border M&A transactions is regularly confronted with the need to verify the authenticity of documents signed by parties established in countries not recognising the eIDAS framework. For due diligence, each signed document (NDA, term sheets, protocols of agreement) must be verified in a documented manner before being filed in the dossier.

The firm adopted a two-level procedure: automatic verification by platform for documents in standard digital format, and recourse to a recognised certifying third party (bilateral chamber of commerce or electronic notary) for documents from countries without eIDAS equivalent. This approach made it possible to produce more robust due diligence reports, reducing requests for clarification from buyers by 35% and shortening transaction closing deadlines by an average of 12 working days. To go further on tools dedicated to legal professionals, see our page on 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 organisational. 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 approached holistically.

Organisations that automate and formalise their verification procedures dramatically reduce their exposure to document fraud, accelerate their contractual cycles and strengthen their regulatory compliance. Conversely, the absence of a 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.