Common Criteria
An international framework for having independent labs evaluate security functions, with assurance levels from EAL1 to EAL7.
Common Criteria (ISO/IEC 15408) works by having a vendor write a security target and an accredited lab evaluate the product against it. The certificate covers that exact configuration and profile, not the product in general. It is easy to read a certificate as a guarantee, but it is really a statement about what was examined.
The EAL levels describe how thorough the examination was. EAL4+ is common for HSMs and smart cards. The time and cost mean that only larger vendors go the whole way, which shows in which products actually carry a certificate.