A running process has several protection key registers ( 16 for Itanium, 4 for HP / PA ).
2.
A translation selected by the virtual address has its key compared to each of the protection key registers.
3.
In the x86, the protection keys architecture allows tagging virtual addresses for user pages with any of 16 protection keys.
4.
In the x86, the protection keys architecture allows tagging virtual addresses for user pages with any of 16 protection keys.
5.
The entire partition, or Multiple Virtual Storage ( MVS ) region, operated with the same memory protection key including the CICS kernel code.
6.
The protection key permissions can be set from user space, allowing applications to directly restrict access to the application data without OS intervention.
7.
All the pages tagged with the same protection key constitute a protection domain, A new register contains the permissions associated with each of the protection domain.
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Sometimes hackers try to pry open the binary files of the programs that they cannot run in order to read the source code and crack the protection key.
9.
A hardware-based protection key, or software keys eliminates the need to ship a physical product, thus enabling end users to quickly install and use an application with minimal fuss.
10.
Since the protection keys are associated with a virtual address, the protection domains are per address space, so processes running in different address spaces can each use all 16 domains.
