The MQ Appliance messaging server must use DoD- or CNSS-approved PKI Class 3 or Class 4 certificates.

Class 3 PKI certificates are used for servers and software signing rather than for identifying individuals. Class 4 certificates are used for business-to-business transactions. Utilizing unapproved certificates not issued or approved by DoD or CNS creates an integrity risk. The messaging server must utilize approved DoD or CNS Class 3 or Class 4 certificates for software signing and business-to-business transactions.