This is type on the imgsec:Key record, classifying what kind of cryptographic key this specific trusted-key entry represents (for example, a Cisco-issued signing key versus one a customer imported) within the image-security policy that owns it. Because different key types can carry different trust levels, an admin auditing which images are allowed onto the fabric interconnects checks this field to confirm whether a given trusted key is an official Cisco key or a locally added one before deciding whether to keep trusting it. A value might read 'cisco' for a factory-embedded signing key versus 'user' for one an admin imported themselves.