Qualified Electronic Signature SaaS Solution for Google Docs & Google Sheets Documents

Qualified e lectronic s ignatures ( QES) a re legally equated with handwritten signatures and are the main mechanism to ensure the authenticity and integrity of electronic data. In E.U., adoption of QES services became easier from the user's perspective, thanks to the adoption of the Regulation (EU) No 910/2014 (the "eIDAS" Regulation) which enables cloud QES. According to the new legislative definitions f rom t he eIDAS Regulation, the signatory is no longer required to own a hardware cryptographic device to obtain a QES, but the secure signature creation device can be managed by the issuing certification authority, namely the trust service provider (TSP). The sole control of the user over her/his private keys stored and used in the cloud shall be assured through the remote signature protocol exposed by the TSP, compliant to corresponding ETSI standards. Thanks to their interoperable character, services exposed by the TSPs are suitable for integration in different document management platforms. However, the full potential of cloud QES has not been reached yet. In order to sustain the adoption of QES, this paper proposes a Software-as-a-Service (SaaS) solution to enable platforms like Google Docs and Google Sheets to directly apply QES on the documents created and used in the cloud. The implemented proof of concept is compliant with the two main signature creation standards: Cloud Signature Consortium (CSC) and OASIS Digital Signature Service (DSS). This paper presents the architecture and implementation details of the proposed solution and also the main challenges encountered during the development of the SaaS platform to offer remote QES services. This paper presents the architecture and implementation details of the proposed solution. Also, we present the main challenges encountered during the development of the SaaS platform to offer QES services.