Assertion: certificate's key | /r/ObjectUse | used for digital signature
Facets:
Source sentences:
text: sky: Specifies the subject's key type, that must be one of the following: signature (that indicates that the key is used for a digital signature), exchange (that indicates that the key is used for key encryption and key exchange), or an integer that represents a provider type.
text: To support non-repudiation, the keys used for digital signature cannot be backed up and must be under the sole control of the user at all times.