Layered certification

A method of assessing security properties of a device that comprises a hierarchy of components, the method comprising:

• retrieving a certification provenance tree structure from a non-transitory computer-readable storage medium to obtain information concerning a layered certification of the device;
• traversing the certification provenance tree structure until the security properties of the device are verified or until a security exception is discovered, the certification provenance tree structure comprising:
• a hierarchy of secure certification provenance document (SCPD) structures, each SCPD structure representing a given component of the device, each SCPD structure comprising:
• a first field that stores a certification proof indicating that security properties of the given component at that given level of the hierarchy have been certified by a certification authority;
• and
• zero or more accreditation information fields, each accreditation information field storing a pointer to an SCPD structure of a component at a next level of the hierarchy of components of the device and providing an indication of assurance that the component at that next level will perform securely within this component at said given level,
• wherein at least one on the SCPD structures includes at least one of the accreditation information fields, such that the component associated with the at least one SCPD structure is verified as performing securely within its deployment environment;
• retrieving a device node structure comprising a first field that stores an identity of the device, a second field that stores an identity of a manufacturer of the device, a third field that stores a device certificate signed by the manufacturer of the device or a certification authority, and a fourth field that provides a pointer to a root SCPD structure of the SCPD structures that represents a root node of the hierarchy of components of the device;
• and
• when the security exception is discovered, denying the device from accessing a service or network.