Telecommunication systems

The present document specifies procedures for:
• the creation of AdES digital signatures (specified in ETSI EN 319 122-1 [i.2], ETSI EN 319 132-1 [i.4], ETSI
EN 319 142-1 [i.6] respectively);
• establishing whether an AdES digital signature is technically valid;
whenever the AdES digital signature is based on public key cryptography and supported by Public Key
Certificates (PKCs). To improve readability of the present document, AdES digital signatures are meant when the term
signature is being used.
NOTE 1: Regulation (EU) No 910/2014 [i.15] defines the terms electronic signature, advanced electronic signature,
electronic seals and advanced electronic seal. These signatures and seals are usually created using digital
signature technology. The present document aims at supporting the Regulation (EU) No 910/2014 [i.15]
for creation and validation of advanced electronic signatures and seals when they are implemented as
AdES digital signatures.
The present document introduces general principles, objects and functions relevant when creating or validating
signatures based on signature creation and validation constraints and defines general classes of signatures that allow for
verifiability over long periods.

The following aspects are considered to be out of scope:
•      generation and distribution of Signature Creation Data (keys, etc.), and the selection and 
use of cryptographic algorithms;

•      format, syntax or encoding of data objects involved, specifically format or encoding for 
documents to be signed or signatures created; and

•      the legal interpretation of any signature, especially the legal validity of a signature.
NOTE 2: The signature creation and validation procedures specified in the present document provide 
several options and possibilities. The selection of these options is driven by a signature creation 
policy, a signature augmentation policy or a signature validation policy respectively. Note that 
legal requirements can be provided through specific policies, e.g. in the context of qualified 
electronic signatures as defined in the Regulation (EU) 910/2014 [i.15].

The present document specifies XAdES digital signatures. XAdES signatures build on XML digital signatures [1], by
incorporation of signed and unsigned qualifying properties, which fulfil certain common requirements (such as the long
term validity of digital signatures, for instance) in a number of use cases.
The present document specifies XML Schema definitions for the aforementioned qualifying properties as well as
mechanisms for incorporating them into XAdES signatures.
The present document specifies formats for XAdES baseline signatures, which provide the basic features necessary for
a wide range of business and governmental use cases for electronic procedures and communications to be applicable to
a wide range of communities when there is a clear need for interoperability of digital signatures used in electronic
documents.
The present document defines four levels of XAdES baseline signatures addressing incremental requirements to
maintain the validity of the signatures over the long term, in a way that a certain level always addresses all the
requirements addressed at levels that are below it. Each level requires the presence of certain XAdES qualifying
properties, suitably profiled for reducing the optionality as much as possible.
Procedures for creation, augmentation, and validation of XAdES digital signatures are out of scope and specified in
ETSI EN 319 102-1 [i.6]. Guidance on creation, augmentation and validation of XAdES digital signatures including the
usage of the different properties defined in the present document is provided in ETSI TR 119 100 [i.11].
The present document aims at supporting electronic signatures in different regulatory frameworks.
NOTE: Specifically but not exclusively, XAdES digital signatures specified in the present document aim at
supporting electronic signatures, advanced electronic signatures, qualified electronic signatures,
electronic seals, advanced electronic seals, and qualified electronic seals as per Regulation (EU)
No 910/2014 [i.1].