BSI Cisco Systems genua GmbH CryptoNext Security BSI Digital signatures are used within X.509 Public Key Infrastructure such as X.509 certificates, Certificate Revocation Lists (CRLs), and to sign messages. This document describes the conventions for using the Stateless Hash-Based Digital Signature Standard (SLH-DSA) in X.509 Public Key Infrastructure. The conventions for the associated signatures, subject public keys, and private key are also described. [EDNOTE: This draft is not expected to be finalized before the NIST PQC Project has standardized FIPS 205 Stateless Hash-Based Digital Signature Standard. The current FIPS draft was published August 24, 2023 for public review. Final versions are expected by April 2024. This specification will use object identifiers for the new algorithms that are assigned by NIST, and will use placeholders until these are released.]