This document specifies a standard XML interface that will enable software applications to call a secured
electronic postal service (SePS), provided by a postal service, which is based on the concepts, schemas and
operations described herein.
The specification provides:
- a definition of standard operations which can be combined to support secured electronic postal services;
- a full description of all mandatory and optional request parameters required for use of these operations;
- a full description of all response elements and the detailed circumstances under which they are returned.
The specification also describes the functionality and edit rules of the actual technical specification artifacts,
which are represented by an XML Schema (XSD) and an associated Web Services Definition Language
(WSDL) specification. The versions of these applicable at the date of publication of this version of the
specification are contained in this document as Annex A and Annex B respectively. These can also be
obtained in electronic format from the UPU Technical Standards CD-ROM or from the UPU Standards
Secretariat.
In case of any conflict between Annex A and other provisions of this specification, Annex A shall be regarded
as definitive.
The SePS schema specification in Annex A is discreet and version specific. Postal Services are free to select
which discrete interface versions they support. However, except in the case of upgrades to V1.15 adopted to
ensure cross-border compatibility, postal services who upgrade from older versions of the schema (e.g. from
V1.14) to a newer one are required to support backward compatibility of previously supported versions of the
SePS interface specification as it applies to both processing requests/responses and honoring previously
issued PostMarkedReceipts. Individual posts are free to address this backward compatibility challenge as they
see fit.
The Version element which is present in every request and which is included in the PostMarkedReceipt
can be used to support this backwards compatibility requirement.
The requirement for backward compatibility does not apply to cross-border scenarios where V1.15 has been
adopted to ensure compatibility. The SePS Interface specification includes a digital signature platform
supporting basic cryptographic service operations as well as a comprehensive framework for the delivery of
evidentiary, witnessing, and non-repudiation services. The specification provides for continued support of
legacy CMS/PKCS7 binary signatures. This approach allows subscribing applications to leverage the
strengths of both protocols and can aid in the migration from one to the other. The schema will continue to
support, in an interchangeable way, use of both CMS/PKCS7 and XMLDSIG artifacts.