Provide system-wide ring of trusted keys

modulename: system_keyring.ko

configname: CONFIG_SYSTEM_TRUSTED_KEYRING

Linux Kernel Configuration
└─>Cryptographic API
└─>Certificates for signature checking
└─>Asymmetric (public-key cryptographic) key type
└─>Provide system-wide ring of trusted keys
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Provide a system keyring to which trusted keys can be added. Keys in
the keyring are considered to be trusted. Keys may be added at will
by the kernel from compiled-in data and from hardware key stores, but
userspace may only add extra keys if those keys can be verified by
keys already in the keyring.

Keys in this keyring are used by module signature checking.

source code: