GlobalSign™, headquartered in Leuven, Belgium, is a long‑established certificate authority (CA) issuing high‑quality digital SSL certificates, S/MIME certificates, and PKI solutions for enterprises, organizations, and individuals. GlobalSign™ was the first European trust center accredited by WebTrust in 2002. SSL issuance is compliant with the EU Digital Signature Directive.

CERTUM – the certification authority – was founded in December 1998 as a division of Unizeto Technologies SA to provide electronic‑signature–related services. It is one of Poland’s oldest and largest public CAs, serving customers in dozens of countries worldwide.

SwissSign is a recognized Swiss trust service provider (TSP) and a leading provider of trust services. It operates a powerful PKI to issue secure digital certificates, electronic signatures, and identities. SwissSign is certified by KPMG for qualified certificates under ZertES and meets WebTrust and ISO 27001 standards.

Actalis is part of the Aruba Group and the only Italian CA in the CAB Forum. Fully eIDAS‑qualified and listed in Open Banking Europe as a qualified trust service provider, it issues qualified website‑authentication certificates and qualified certificates for electronic seals under PSD2.

Sectigo, formerly Comodo, is one of the world’s largest providers of digital encryption. Its offerings include a full range of high‑quality SSL certificates, from domain‑validated to email certificates, and extensive PKI solutions for large organizations.

D-TRUST GmbH, based in Berlin, has been listed since 2016 as a qualified trust service provider under the European eIDAS regulation by the German Federal Network Agency. The company, which emerged from Bundesdruckerei, issues qualified digital certificates for electronic signatures, seals, and qualified remote signatures. It also offers additional PKI products and services, such as the AusweisIDent service.