I'm just using the term casually. Technically I think it's a hierarchy of keys wrapping keys. It's all explained here: https://www.apple.com/business/docs/iOS_S

I'm just using the term casually. Technically I think it's a hierarchy of keys wrapping keys. It's all explained here: https://www.apple.com/business/docs/iOS_Security_Guide.pdf https://www.apple.com/business/docs/iOS_Security_Guide.pdf