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PAdES

PAdES, or PDF Advanced Electronic Signatures, is a set of technical standards developed by the European Telecommunications Standards Institute (ETSI) that specify the creation and validation of advanced electronic signatures embedded within PDF documents, extending the core PDF format defined in ISO 32000-1 through restrictions and alternative encodings equivalent to those in CAdES (CMS Advanced Electronic Signatures).^[1] These standards ensure the authenticity, integrity, and long-term validity of signed PDFs, supporting secure electronic transactions in business and governmental contexts by incorporating public key infrastructure (PKI) elements and validation data.^[1] Developed under ETSI's Technical Committee for Electronic Signatures and Infrastructures (TC ESI), PAdES aligns closely with the eIDAS Regulation (EU) No 910/2014, which mandates interoperability and legal recognition for qualified electronic signatures across EU member states. Qualified electronic signatures created using PAdES have the equivalent legal effect of a handwritten signature.^[1]^[2] The standard emphasizes long-term validation to address challenges like certificate expiration or revocation, using components such as the Document Security Store (DSS) for signature attributes and Validation Related Information (VRI) for embedded verification data.^[1] PAdES defines baseline profiles with escalating levels of assurance: the B-B (Basic-Basic) level provides core signature functionality without timestamps; B-T adds a trusted timestamp for signing time; B-LT incorporates long-term validation data like revocation information; and B-LTA enables archival validity through document timestamps that protect against future changes.^[1] These profiles facilitate interoperability testing via ETSI Plugtests events and support integration with other ETSI standards, including CAdES for general CMS-based signatures and XAdES for XML documents, forming a cohesive framework for digital trust services.^[3]

Overview

Definition and Scope

PAdES, which stands for PDF Advanced Electronic Signatures, is a set of standards developed by the European Telecommunications Standards Institute (ETSI) for creating and validating advanced electronic signatures embedded within PDF documents.^[1] These signatures conform to the requirements outlined in ETSI EN 319 142-1 and ETSI EN 319 142-2, ensuring compatibility with the PDF format as defined in ISO 32000-1.^[1] The core purpose of PAdES is to guarantee the long-term validity, integrity, and non-repudiation of electronic signatures in PDF files, thereby fostering trust in electronic transactions for business and governmental applications across Europe and beyond.^[1] By extending the baseline PDF signature mechanisms in ISO 32000-1 with additional attributes and encoding alternatives—such as those equivalent to CMS Advanced Electronic Signatures (CAdES)—PAdES supports robust verification even after extended periods, protecting against alterations or loss of supporting data.^[1] In terms of scope, PAdES is limited to the PDF document format and focuses exclusively on advanced electronic signatures, excluding basic or simple electronic signatures as well as signatures in non-PDF file types.^[1] It aligns with the concept of an Advanced Electronic Signature (AdES), defined under EU Directive 1999/93/EC as an electronic signature uniquely linked to the signatory, capable of identification, created under the signatory's sole control, and detectable of any data changes.^[4] Furthermore, PAdES facilitates the creation of Qualified Electronic Signatures (QES) when implemented with qualified certificates and signature creation devices, as required under the eIDAS Regulation (EU) No 910/2014.^[1]

Relation to Electronic Signatures and PDF

PAdES, or PDF Advanced Electronic Signatures, serves as a specialized profile within the broader framework of Advanced Electronic Signatures (AdES), as outlined in the eIDAS Regulation (EU) No 910/2014, which establishes a hierarchy of electronic signatures including simple electronic signatures (SES), advanced electronic signatures (AES), and qualified electronic signatures (QES). PAdES aligns with the AES and QES levels by providing standardized constraints that ensure the signature is uniquely linked to the signatory, allows identification of the signer, is created using secure tools under the signer's sole control, and remains under the signer's control during the signing process.^[1] This positioning enables PAdES to meet the regulatory requirements for higher-assurance signatures suitable for legal and business transactions across the European Union, while building on the foundational AdES principles to adapt them for PDF-specific use cases.^[1] The integration of PAdES with PDF technology leverages the core capabilities defined in ISO 32000-1, the international standard for the Portable Document Format, which specifies mechanisms for embedding digital signatures directly into PDF files via the Signature Dictionary.^[5] PAdES extends this by incorporating the Cryptographic Message Syntax (CMS) from RFC 5652, using DER-encoded SignedData objects to encapsulate the signature, signed attributes, and unsigned attributes in a manner equivalent to CAdES signatures. This CMS-based structure ensures that the embedded signature is self-contained and verifiable, with support for additional elements like signer attributes and certificate chains, all while preserving the PDF's portability and viewer-agnostic rendering.^[6] Compared to native PDF signatures under ISO 32000-1, which offer basic cryptographic embedding without mandated validation processes, PAdES introduces rigorous constraints to enhance reliability and compliance.^[5] These include requirements for timestamping using RFC 3161-compliant tokens to prove signing time, integration of revocation information such as CRLs or OCSP responses for certificate status checks, and the use of a Document Security Store (DSS) to archive validation data for long-term verification.^[6] Such features promote interoperability across diverse PDF software and signing tools, reducing validation failures in cross-border scenarios and ensuring signatures remain valid even after certificate expiration.^[6] PAdES distinctly emphasizes the embedding and integrity of electronic signatures within PDF documents, distinguishing it from the format's broader capabilities for content creation, annotation, or multimedia inclusion.^[5] By focusing exclusively on signature-related operations—such as creation, validation, and archival—PAdES avoids interference with non-signature PDF functionalities like form filling or page manipulation, thereby maintaining document stability while fulfilling electronic signature mandates.^[6]

Historical Development

Initial Specifications

The PAdES (PDF Advanced Electronic Signature) specifications originated from efforts by the European Telecommunications Standards Institute (ETSI) Technical Committee on Electronic Signatures and Infrastructures (ESI) to address the requirements of the EU Directive 1999/93/EC, which established a framework for electronic signatures to promote trust and interoperability in electronic transactions across member states. Published initially as the ETSI TS 102 778 series between 2009 and 2010, these specifications provided the foundational standards for embedding advanced electronic signatures in PDF documents, ensuring compliance with European legal recognition of qualified electronic signatures while leveraging the widespread adoption of the PDF format.^[7] The multi-part structure of ETSI TS 102 778 was designed to offer a comprehensive framework: Part 1 delivers an overview and general guidance on PAdES usage and implementation; Part 2 outlines basic profiles, such as PAdES-BES for electronic signatures with signer authentication and document integrity; Part 3 details enhanced profiles, including PAdES-EPES for signatures bound to explicit policies; Part 4 focuses on long-term validation mechanisms (PAdES-LTV) to maintain signature validity over time; Part 5 addresses profiles for XML content using XAdES signatures embedded in PDFs; and Part 6 specifies visual representations of signatures for user-friendly verification. This modular approach allowed for progressive adoption based on specific needs, building directly on PDF signature capabilities defined in ISO 32000-1.^[7]^[8]^[9]^[10]^[11]^[12] Central innovations in these initial specifications involved PDF-specific extensions that adapted CAdES (CMS Advanced Electronic Signatures) principles for PDF environments, enabling the inclusion of trusted timestamps per RFC 3161 and signer attributes such as certificates, revocation status (via OCSP or CRL), signing reasons, and policy identifiers to enhance non-repudiation and cross-border usability. These elements ensured signatures could be validated without relying on real-time access to external authorities, fostering reliable interoperability in a pre-eIDAS European context. The standards were primarily driven by the need to support secure e-commerce transactions and governmental document workflows, where PDF's portability made it ideal for legally binding electronic exchanges.^[8]^[9]

Updates for eIDAS Compliance

The eIDAS Regulation (EU) No 910/2014, which entered into force on July 1, 2016, established a harmonized framework for electronic identification and trust services across the European Union, including requirements for qualified electronic signatures that must conform to specific technical standards for long-term validity and interoperability. This regulation prompted the need for updated PAdES specifications to ensure compliance with advanced and qualified electronic signature formats, building on prior ETSI work while addressing new mandates for trust service integration.^[13] In response, ETSI superseded the earlier ETSI TS 102 778 series—initially published between 2009 and 2010—with the EN 319 142 series in 2016, elevating PAdES from a technical specification to a full European Norm to align directly with eIDAS provisions. In July 2015, ETSI published the precursor ETSI TS 119 142 series, which was withdrawn and replaced by the EN 319 142 series in 2016 as full European Norms.^[14] The latest iterations include EN 319 142-1 V1.2.1 (January 2024) for baseline PAdES signatures and EN 319 142-2 V1.2.1 (July 2025) for extended profiles, incorporating refinements for enhanced compatibility with PDF structures and signature validation processes.^[1]^[6] Key updates in the EN 319 142 series emphasize improved long-term validation capabilities through refined archival mechanisms, deeper integration with eIDAS trust services for certificate and revocation checking, and stronger alignment with RFC 5126's advanced CMS features to ensure equivalence with CAdES profiles for extended signature longevity.^[1]^[15] These changes facilitate more robust handling of timestamps and complete validation data, reducing dependency on external references over time while maintaining compliance with ISO 32000-1 PDF signatures.^[6] ETSI maintains the EN 319 142 standards through periodic revisions to counter emerging security threats, such as vulnerabilities from quantum computing that could undermine current cryptographic algorithms, and to incorporate support for PDF 2.0 as defined in ISO 32000-2, ensuring ongoing adaptability for future-proof electronic signatures.^[16]

Standards and Profiles

Baseline Signatures

The ETSI EN 319 142-1 standard specifies the formats for PAdES baseline signatures, which provide the basic features necessary for a wide range of business and governmental applications by integrating CMS-based electronic signatures into PDF documents as defined in ISO 32000-1.^[1] These profiles, PAdES-BES and PAdES-EPES, incorporate signed and unsigned attributes equivalent to those in CAdES baseline signatures from ETSI EN 319 122-1 to ensure interoperability and essential functionality for initial signature verification.^[17] The baseline profiles build upon the foundational specifications outlined in the earlier ETSI TS 102 778 series and define four levels: B-B, B-T, B-LT, and B-LTA, with escalating assurance for time-stamping and long-term validation. PAdES-BES, corresponding to the B-B (basic-basic) level and basic electronic signature profile, mandates the inclusion of the signer's certificate within the SignedData structure to enable verification of the signer's identity.^[1] It requires essential signed attributes such as message-digest for content integrity and content-type to identify the signed data as a PDF document, while allowing optional unsigned attributes like signer-attributes-v2 for additional signer information, content-time-stamp for signing time evidence, and commitment-type-indication to declare the signature's purpose.^[1] This profile ensures short-term signature validity by protecting against immediate alterations but does not incorporate mechanisms for long-term validation, such as revocation status beyond the signature's creation time.^[1] The B-T level extends B-B by adding a trusted timestamp (signature-time-stamp or content-time-stamp) to prove the signature's existence at a specific point in time.^[1] The B-LT level further incorporates revocation data, such as OCSP responses and CRLs, into the Document Security Store (DSS) to verify the status of the signer's certificate and chain at signing time, enabling long-term validation.^[1] The B-LTA level provides archival validity by adding document-time-stamps that cover the entire signed PDF, including prior validation data and timestamps, protecting against future cryptographic obsolescence.^[1] PAdES-EPES extends the PAdES-BES profile by requiring the explicit inclusion of the signature-policy-identifier as a signed attribute, which binds the signature to a specific policy through its object identifier (OID).^[1] This OID, as structured in ETSI EN 319 122-1 and aligned with CMS Advanced Electronic Signatures formats, uniquely identifies the rules governing the signature's creation and validation, such as community-specific or jurisdictional policies.^[17] The attribute includes a hash of the policy document to verify its integrity, enhancing the signature's legal and procedural context without altering the core integrity protections of PAdES-BES.^[17] The EPES requirements apply across B-B, B-T, B-LT, and B-LTA levels. To safeguard the underlying PDF against unauthorized changes, all baseline profiles require conformance to the DocMDP transform method in ISO 32000-1, which permits only approved modifications like annotations or form filling, or the UR3 approval signature transform for stricter document approval workflows.^[1] These mechanisms embed permissions directly in the PDF's signature dictionary, ensuring that any post-signature alterations invalidate the baseline signature while maintaining compatibility with standard PDF viewers.^[1]

Extended and Long-Term Signatures

Extended PAdES signatures, as defined in ETSI EN 319 142-2, build upon baseline profiles to provide additional flexibility for scenarios where strict baseline constraints cannot be met, such as including unsigned attributes before signed ones or supporting external commitments.^[6] These extended profiles, including PAdES-E-BES, PAdES-E-EPES, and PAdES-E-LTV, incorporate similar mechanisms for durability, including trusted timestamps and revocation information in the DSS, but with relaxed requirements to ensure verifiability over extended periods.^[6] The extended profiles address incremental requirements for long-term validation, such as embedding validation data in the Document Security Store (DSS) to support offline verification without relying on external authorities.^[6] Long-term features rely on the inclusion of complete revocation information—OCSP responses confirming certificate validity and CRLs listing revoked certificates—embedded in the DSS.^[1] For archive validation, document timestamps per ETSI TS 119 142-3 play a critical role in long-term validation (LTV), where PAdES-DTS profiles apply ETSI.RFC3161-compliant timestamps to the whole document, ensuring its integrity and existence without authenticating the signer.^[18] This allows for ongoing augmentation, such as adding new timestamps and updated DSS entries, to maintain validity over decades. Profiles like PAdES-E-LTV combine multiple layers of timestamps—including signature-time-stamps, validation-data timestamps, and archive-time-stamps—to enable post-signature augmentation without invalidating earlier components, as the structure preserves the original signed data while appending new verification elements in the PDF.^[6] This approach, aligned with eIDAS requirements for qualified electronic signatures, facilitates the evolution of the signature container over time, ensuring perpetual verifiability in archival contexts.^[6]

Technical Specifications

Signature Creation Process

The creation of a PAdES signature begins with prerequisites centered on cryptographic security and regulatory compliance. Signers must utilize qualified electronic signature certificates issued by a Qualified Trust Service Provider (QTSP) as defined under the eIDAS Regulation, ensuring the certificate meets requirements for advanced or qualified electronic signatures, including secure key generation and storage. These certificates are typically based on X.509 standards and must employ approved algorithms, such as RSA or ECDSA with key lengths of at least 2048 bits for RSA or 256 bits for ECDSA.^[1] The core process involves several sequential steps to generate a compliant signature. First, the content of the PDF document is hashed using a secure cryptographic hash function, such as SHA-256 or stronger (e.g., SHA-384 or SHA-512), to produce a digest that represents the document's integrity without embedding the full content in the signature.^[1] This hash is then incorporated into a Cryptographic Message Syntax (CMS) SignedData structure per RFC 5652, which encapsulates the signer's private key operation to create the digital signature, including mandatory signed attributes like the message digest, content type (id-data), and a reference to the signer's certificate (e.g., via ESS signing-certificate-v2 attribute).^[1] The resulting DER-encoded SignedData object is embedded into the PDF file via a signature dictionary as specified in ISO 32000-1, clause 12.8, under the /Contents key, which may also include optional PDF-specific attributes such as the signer's name (/Name), location (/Location), and signing reason (/Reason) to provide contextual information about the signature act.^[1] For profiles requiring a signature policy, such as EPES, the CMS structure must include a signature-policy-identifier attribute referencing the applicable policy OID and hash to enforce explicit rules for the signing process.^[1] Baseline profiles like BES, which form the foundation for PAdES, focus on these basic elements without additional policy enforcement.^[1] Implementation often leverages specialized PDF libraries integrated with cryptographic providers to handle these operations efficiently. For instance, the iText library supports PAdES creation through its PdfPKCS7 class for CMS handling and PdfSignatureAppearance for embedding, paired with Java Cryptography Extension (JCE) providers like Bouncy Castle for key operations and hashing.^[19] Similarly, Apache PDFBox enables PAdES-compliant signing via its PDSignature and ExternalSigningSupport classes, allowing external key providers for the signing step while ensuring DER encoding and attribute inclusion. Key constraints ensure the signature's integrity post-creation: the signed PDF must not undergo any modifications that alter the hashed byte range, except for permitted Long-Term Validation (LTV) augmentations such as adding revocation information or timestamps to the Document Security Store (DSS) without invalidating the original signature.^[1] Generators must also verify that the signature handler is registered in the PDF's /SigFlags to support proper processing.^[1]

Validation and Attributes

Validation of PAdES signatures involves a series of cryptographic and procedural checks to ensure the integrity, authenticity, and validity of the electronic signature embedded in a PDF document. The process begins with verifying the signature's integrity by computing the hash of the signed content and comparing it to the message digest included in the signed attributes; this confirms that the document has not been altered since signing.^[20]^[15] Next, the certificate chain is validated by building the path from the signer's certificate to a trusted root, using certificates embedded in the SignedData structure or referenced in unsigned attributes.^[20] Revocation status is then assessed by checking OCSP responses or CRLs for the signer's and timestamp authority's certificates, which are typically embedded in the Document Security Store (DSS) for baseline profiles.^[20] Finally, any timestamps, such as the signature-time-stamp, are validated against a trusted time source to confirm the signing occurred at the claimed time.^[20] PAdES signatures incorporate signed and unsigned attributes derived from CMS and CAdES specifications to provide essential metadata. Signed attributes, which are protected by the signer's private key, include the content-type (e.g., application/pdf) to identify the signed data format and the message-digest (e.g., a SHA-256 hash) to enable integrity verification.^[15] Additional signed attributes may encompass the signing-certificate, which references the signer's X.509 certificate for authenticity checks.^[15] Unsigned attributes, not covered by the signature's cryptographic protection, include the signature-time-stamp token for proving the signature's existence at a specific time and complete certificate references (per RFC 5126), which list identifiers for all certificates in the validation chain to facilitate long-term verification without external dependencies.^[15]^[20] For long-term validation in LT (Long-Term) and LTA (Long-Term with Archive timestamp) profiles, PAdES ensures future-proofing by embedding or referencing all necessary dependencies within the PDF. In the LT profile, certificates, revocation information (e.g., CRLs or OCSP responses), and attribute references are included in the DSS to allow validation without relying on potentially unavailable external sources.^[20] The LTA profile extends this by adding a document-time-stamp over the entire DSS content, cryptographically binding all validation material and preventing undetected alterations over extended periods.^[20] Error handling in PAdES validation follows ETSI guidelines, categorizing outcomes as VALID, INVALID, or INDETERMINATE to guide verifiers. A signature is deemed VALID (TOTAL-PASSED) if all cryptographic checks succeed, the certificate chain is trustworthy, and policy constraints are met, confirming full compliance.^[21] It is INVALID (TOTAL-FAILED) if integrity fails, the certificate was revoked or expired at signing time, or the format deviates from standards, rendering it unreliable.^[21] An INDETERMINATE result occurs when data is insufficient—such as missing proof of existence (POE) or unverifiable revocation—preventing a conclusive assessment, often requiring additional information for resolution.^[21]

Legal and Regulatory Aspects

eIDAS Regulation Compliance

The eIDAS Regulation, officially Regulation (EU) No 910/2014, provides a harmonized framework for electronic identification and trust services in the European Union, categorizing electronic signatures into three levels: simple electronic signatures (SES) for basic use cases, advanced electronic signatures (AES) with enhanced security linking the signature to the signer and data, and qualified electronic signatures (QES) offering the highest legal equivalence to handwritten signatures. PAdES, standardized for embedding AES and QES within PDF documents, aligns with eIDAS by supporting these higher assurance levels through cryptographic mechanisms that ensure document integrity and authenticity in electronic transactions.^[14] For qualified electronic signatures (QES) in PAdES, compliance with eIDAS requires the use of a Qualified Signature Creation Device (QSCD), a certified secure hardware or software component that safeguards the signer's private key and prevents unauthorized access, or equivalent qualified remote signing solutions that maintain equivalent security.^[22] Furthermore, PAdES QES must rely on qualified certificates issued by a Qualified Trust Service Provider (QTSP), an audited entity authorized under eIDAS to deliver trust services such as certificate issuance, ensuring verifiable signer identity and compliance with EU-wide standards; AES may use secure certificates but not necessarily qualified ones.^[23] The ETSI EN 319 142 series of profiles defines PAdES specifications to fulfill eIDAS Article 32 requirements for qualified electronic signature validation, incorporating attributes that provide non-repudiation—preventing the signer from denying their involvement—and clear identifiability of the signer through embedded metadata and certificate validation processes.^[24] These profiles establish baseline, extended, and long-term signature levels, embedding timestamps and revocation information to sustain validity against future cryptographic changes.^[1] PAdES standards, as updated in ETSI EN 319 142-1 V1.2.1 (January 2024), align with the original eIDAS Regulation (EU) No 910/2014. Ongoing revisions are anticipated to support eIDAS 2.0 (Regulation (EU) 2024/1183), which entered into force on May 20, 2024, including new validation rules under Article 32a for advanced electronic signatures based on qualified certificates to enhance cross-border interoperability, particularly in the European Digital Identity Wallet ecosystem. As of November 2025, eIDAS 2.0 implementation is underway, with implementing acts adopted by November 2024, member state updates by May 2025, and large-scale pilots for EUDI Wallets ongoing ahead of mandatory rollout by 2026.^[25]^[26]

Admissibility and Recognition

In the European Union, PAdES signatures that qualify as Qualified Electronic Signatures (QES) under the eIDAS Regulation hold the same legal effect as handwritten signatures, providing full evidentiary weight in judicial proceedings. This equivalence, established by Article 25(2) of Regulation (EU) No 910/2014, ensures that such signatures cannot be denied legal recognition solely on the grounds of their electronic form and are admissible as evidence in courts across all member states for purposes including contracts, regulatory filings, and official administrative documents.^[24] PAdES, as defined in ETSI EN 319 142-1, serves as the standardized format for embedding these QES into PDF documents, leveraging qualified certificates and secure signature creation devices to meet eIDAS requirements for high-assurance electronic authentication. Beyond the EU, PAdES QES recognition in non-EU jurisdictions often relies on bilateral or multilateral agreements that align with international frameworks such as the UNCITRAL Model Law on Electronic Signatures (2001), which promotes functional equivalence between electronic and handwritten signatures while emphasizing technical reliability. For instance, mutual recognition agreements exist with select third countries, including Ukraine's inclusion in the EU's Trusted Lists for Advanced Electronic Signatures since 2023, allowing PAdES QES to be validated and enforced similarly to domestic signatures. In the United States, the ESIGN Act (2000) grants general legal validity to electronic signatures, including those in PDF format like PAdES, provided they demonstrate intent and integrity; however, challenges arise in jurisdictions lacking specific standards for PDF-based signatures, such as certain Asian or African countries where electronic signatures may require additional notarization or face inconsistent court acceptance due to underdeveloped regulatory frameworks.^[27]^[28]^[29] Practical applications highlight PAdES's role in high-stakes EU processes, such as public tenders where platforms like those under the Tenders Electronic Daily (TED) system mandate PAdES QES for bid submissions to ensure tamper-proof authenticity and compliance with procurement directives. Similarly, in notarial acts, PAdES facilitates electronic authentication in countries like Italy, where notaries use it for deeds and wills under national eIDAS implementations, streamlining cross-border enforceability. To maintain admissibility over extended periods, such as decades-long archival needs in legal or financial contexts, the PAdES Long-Term Archival (LTA) profile is essential, as it embeds validation data (including timestamps and revocation information) to support ongoing verifiability even after certificate expiration, per ETSI specifications.^[30]^[31] Despite these strengths, PAdES admissibility hinges on rigorous validation at the point of reliance, with courts requiring proof of signature integrity and signer identity through embedded attributes or external trusted lists. In disputes, forensic tools such as those outlined in ETSI TR 102 923 enable detailed examination of signature components, including cryptographic hashes and audit trails, to resolve challenges related to alleged tampering or invalidation over time. Failure to achieve proper long-term validation can undermine evidentiary value, particularly in international cases where differing technical standards complicate cross-jurisdictional enforcement.^[32]^[33]

Implementation and Applications

Tools and Software Support

Several open-source libraries facilitate the creation and validation of PAdES signatures by providing APIs for embedding digital signatures within PDF documents and handling associated cryptographic operations. The iText library, an open-source Java and .NET PDF manipulation tool, supports PAdES signature creation through its high-level API, including two-phase signing workflows for preparing documents with signature containers and finalizing them with qualified certificates.^[19] It integrates seamlessly with the Bouncy Castle cryptographic library for advanced features like certificate handling and hashing algorithms required for ETSI-compliant signatures.^[34] Similarly, Apache PDFBox, a Java-based open-source PDF library, enables the creation, signing, and validation of digital signatures in PDFs, with explicit support for PAdES formats including embedding signatures and verifying their integrity using external cryptographic providers like Bouncy Castle. Bouncy Castle itself serves as a foundational FIPS-certified cryptographic API for Java and C#, providing the necessary primitives for PAdES such as CMS/PKCS#7 encoding, timestamping, and long-term validation attributes, often used in conjunction with PDF libraries to ensure compliance with ETSI standards.^[35] Commercial tools offer robust, user-friendly support for PAdES, particularly in enterprise environments requiring qualified electronic signatures (QES). Adobe Acrobat provides native PAdES support aligned with PDF 1.7 (introduced in Acrobat 11), in line with ETSI TS 102 778 standards for advanced electronic signatures, including creation, validation, and levels up to B-LTA for long-term archival.^[36] DocuSign's eSignature platform incorporates PAdES for PDF documents under eIDAS regulations, enabling QES through integration with qualified trust service providers (QTSPs) and supporting long-term validation (LTV) formats like PAdES-B-LTV to ensure ongoing verifiability.^[37] GlobalSign, as a QTSP, delivers PAdES-compatible platforms for QES, including digital signing services that embed advanced signatures in PDFs with compliance to ETSI EN 319 142 profiles, facilitating secure document workflows across EU member states.^[38] Validation of PAdES signatures is supported by ETSI-compliant software and online tools, ensuring adherence to standards for integrity and authenticity checks. The Digital Signature Service (DSS) library, an open-source Java framework developed by the European Commission, implements creation, extension, and validation of PAdES signatures, covering baseline levels and extended profiles while supporting integration with trust services for certificate revocation and timestamp verification.^[39] Online validators from QTSPs, such as SEFIRA's qualified validation service, allow users to verify PAdES documents remotely, checking signature validity, certificate chains, and compliance with eIDAS requirements through web-based interfaces.^[40] PAdES tools and software generally ensure compatibility across baseline levels B-B (basic), B-T (with timestamps), B-LT (long-term), and B-LTA (archival), with major PDF viewers like Adobe Acrobat Reader and open-source alternatives supporting validation of these levels natively. Recent updates in ETSI EN 319 142-2 (July 2025) enhance compatibility by aligning PAdES profiles with the latest ISO 32000-2 PDF specifications, incorporating improvements for extended signatures and integration with modern cryptographic algorithms, which have been adopted in updated versions of libraries like DSS and commercial tools to maintain interoperability.^[6]

Practical Use Cases

PAdES signatures are widely applied in governmental processes across the European Union to ensure the authenticity and integrity of electronic documents, particularly in PDF format, aligning with eIDAS requirements for qualified electronic signatures. For instance, they facilitate the secure electronic filing of tax returns, where public administrations use PAdES to sign and seal declarations, enabling verifiable submissions without physical presence. In court proceedings, PAdES supports the submission of legal documents in EU member states, providing tamper-evident records that maintain evidentiary value over time. In Italy, advanced or qualified electronic signatures are required for certain official documents, such as those in finance and judicial contexts, which can be implemented using PAdES for PDF formats, to streamline processes while preserving legal admissibility.^[41]^[31] In business environments, PAdES enables efficient contract signing within supply chains, allowing multiple parties to apply sequential or parallel signatures to PDF agreements such as vendor contracts and procurement documents, reducing delays in international trade. For invoice authentication, PAdES aligns with EU VAT directives by ensuring the origin, integrity, and legibility of electronic invoices through advanced signatures, which helps businesses comply with reporting obligations and combat fraud in cross-border transactions. This format is particularly valuable for non-repudiation in B2B exchanges, where signed PDFs serve as reliable proof in audits.^[42]^[43] Within healthcare, PAdES secures patient consent forms by embedding qualified signatures with timestamps, ensuring compliance with GDPR for data protection while creating immutable records of informed consent. In finance, it supports compliant wire transfers through signed authorization PDFs that include audit trails via long-term validation attributes, facilitating KYC processes and reducing risks in loan agreements or investment contracts. These applications provide verifiable trails for regulatory oversight, such as in anti-money laundering checks.^[42]^[44] Handling multi-signer workflows presents challenges in PAdES implementations, such as coordinating sequential signatures without invalidating prior ones, which requires careful management of incremental updates to avoid breaking existing validations. Solutions involve using tools that support parallel signing paths and real-time status tracking, ensuring all parties' contributions remain intact and verifiable. Migration from legacy PDF signatures to PAdES-LTA for archival purposes addresses issues like certificate expiry and algorithm obsolescence by adding document timestamps and revocation data post-signing, enabling long-term readability even after 10-20 years; this process often automates certificate renewal and PDF optimization to minimize disruptions in existing archives.^[42]^[45]

References

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[PDF] ETSI EN 319 142-2 V1.2.1 (2025-07)
Jun 25, 2025 · PAdES-E-BES level allows basic digital signatures embedded within a PDF file. There is an unambiguous connection from the signature to the ...
[15]
RFC 5126 - CMS Advanced Electronic Signatures (CAdES)
This document defines the format of an electronic signature that can remain valid over long periods. This includes evidence as to its validity.Missing: PAdES 319 142 alignment
[16]
ESI Activities - ETSI Portal
Part 1: Overview and common data structures · Part 2: Certificate profile for certificates issued to natural persons · Part 3: Certificate profile for ...<|control11|><|separator|>
[17]
[PDF] ETSI EN 319 122-1 V1.2.1 (2021-10)
Oct 18, 2021 · This standard is about CAdES digital signatures, part of Electronic Signatures and Infrastructures (ESI), focusing on building blocks and ...
[18]
[PDF] ETSI TS 119 142-3 V1.1.1 (2016-12)
The type of PAdES signature defined in the present document is called PAdES-DTS and it builds on PDF signatures as specified in ISO 32000-1 [1]. While other ...
[19]
Solutions for PDF electronic digital signature integration - iText
iText supports digital signatures for PDF, ensuring non-repudiation, integrity, and authenticity. It uses PAdES and is compatible with PDF 2.0.Missing: PDFBox | Show results with:PDFBox
[20]
[PDF] ETSI TS 103 172 V2.2.2 (2013-04)
ETSI TS 103 172 is a technical specification for Electronic Signatures and Infrastructures (ESI), specifically the PAdES Baseline Profile.
[21]
[PDF] ETSI EN 319 102-1 V1.3.1 (2021-11)
Feb 28, 2022 · The signature validation process results into. INDETERMINATE because some constraints on the order of signature time-stamps and/or. Signed ...
[22]
eIDAS QSCD - Entrust
Under eIDAS, a QSCD is a secure hardware device for creating signature and seal data, mandatory for qualified electronic signatures.
[23]
What is a Qualified Trust Service Provider? (QTSP?) - Utimaco
The electronic Identification and Signature (eIDAS) Regulation defines a qualified trust service provider (QTSP) as a natural or a legal person who provides ...Qualified Trust Service... · A Trust Service Consists Of · Solutions
[24]
eSignature FAQ - European Commission
The three main formats for digital signature XAdES, CAdES, and PAdES, as well as their four levels of baseline signatures profile being supported in compliance ...Esignature · General Questions · Trusted List Browser
[25]
eIDAS 2.0 | Updates, Compliance, Training
The Regulation amends Regulation (EU) 910/2014 on electronic identification ... It entered into force on May 20, 2024. Final text - Regulation (EU) ...
[26]
UNCITRAL Model Law on Electronic Signatures (2001)
The Model Law on Electronic Signatures (MLES) aims to enable and facilitate the use of electronic signatures by establishing criteria of technical reliability.Missing: PAdES mutual US Act
[27]
eSignatures in focus: Navigating electronic identification and trust ...
Oct 21, 2024 · This guide provides a concise overview of eID means and trust services in Ukraine, with a focus on eSignatures as instruments enabled by eID means and their ...Missing: PAdES | Show results with:PAdES
[28]
[PDF] Electronic Signatures in Global and National Commerce Act - FDIC
The E-Sign Act allows the use of electronic records to satisfy any statute, regulation, or rule of law requiring that such information be provided in writing, ...Missing: PAdES mutual UNCITRAL<|control11|><|separator|>
[29]
How to submit a public tender with a qualified signature? - ZealiD
Sep 27, 2024 · To submit a tender with a qualified signature, prepare documents, obtain a QES, sign documents, use the online portal, and upload signed ...
[30]
E-signatures in finance & NPL transactions in Italy | CMS Expert Guide
Dec 1, 2021 · Under Italian law, all documents can be in electronic form and bear e-signatures in compliance with the European standards CAdES, PAdES and XAdES.
[31]
[PDF] ETSI TR 102 923 V1.1.1 (2010-07)
If a PAdES Part 3 incorporates the signature-policy-identifier CAdES unsigned attribute, then this is a. PAdES-EPES, which provides same semantics as CAdES-EPES ...
[32]
Digital Signature – Electronic Signature (eSignature) - Forensic Notes
Dec 21, 2018 · Forensic Notes Proprietary Validation Tool will complete the complex validation and simply display the validity of the document as either being ...Missing: PAdES | Show results with:PAdES
[33]
PAdES Signing High Level API - iText Knowledge Base
The iText PAdES API uses `PdfPadesSigner` and `PadesTwoPhaseSigningHelper` for easy two-step signing, avoiding incremental processes for different PAdES levels.
[34]
Bouncy Castle open-source cryptographic APIs
Bouncy Castle is one of the most widely used FIPS-certified open-source cryptographic APIs for Java and C#, including quantum-ready cryptography support and ...Download Bouncy Castle Java · Documentation · Download BC C# .NET · AboutMissing: iText PDFBox
[35]
Supported Standards — Acrobat Desktop Digital Signature Guide
Jul 23, 2025 · Adobe Inc. Describes PDF media type, digital signatures, and encryption. ETSI 102 778 PDF Advanced Electronic Signatures (PAdES), Parts 1 ...
[36]
eIDAS FAQ – Understanding the EU's latest electronic signature ...
Jul 3, 2025 · Docusign's Standards-Based Signatures' technology is also underpinned by eIDAS-recommended technical standards for electronic signature, ...
[37]
Qualified Trust Services for eIDAS | GlobalSign
As a qualified trust service for eIDAS provider, we offer a range of digital signing solutions to support advanced and qualified electronic signatures.
[38]
Digital Signature Service - European Commission
Jul 24, 2024 · Directive 1999/93/EC of the European Parliament and of the Council of 13 December 1999 on a Community framework for electronic signatures.
[39]
QTSP - sefira.com
SEFIRA is a provider of a qualified validation service in accordance with eIDAS. The service allows you to verify the validity of qualified signatures.
[40]
eSignature FAQ
### Summary of Legal Admissibility and Recognition of Qualified Electronic Signatures (QES) under eIDAS
[41]
What Is a PAdES Signature? A Complete Guide (2025) - Certinal
Jun 4, 2025 · Short for PDF Advanced Electronic Signature, PAdES is a globally recognized standard for embedding digital signatures directly into PDF files — ...
[42]
[PDF] Explanatory notes VAT invoicing rules - Taxation and Customs Union
Oct 5, 2011 · The taxable person can choose to ensure the identity of the issuer of an invoice by for example an advanced electronic signature or EDI.Missing: PAdES authentication
[43]
What is PAdES? A Complete Guide to PDF Signatures
Jul 23, 2025 · PAdES stands for PDF Advanced Electronic Signatures. It is a specialized standard that defines how a PDF signature can be applied, ensuring the ...Missing: definition | Show results with:definition
[44]
e-Signatures Demystified: Understanding PAdES for Secure PDF ...
Sep 19, 2025 · In contrast, PAdES (PDF Advanced Electronic Signature) focuses on PDF files, emphasizing the seamless integration of signatures into documents.