OPC Unified Architecture – Part 12: Discovery and Global Services
7.8.4.9 RsaSha256ApplicationCertificateType
This type is used to describe Certificates intended for use as an ApplicationInstanceCertificate. They shall have an RSA key size of 2048, 3072 or 4096 bits. All Applications which support the Basic256Sha256 profile (see OPC 10000-7) shall have a Certificate of this type. This type is defined in Table 54.