...
An initial key is generated by the installer in a special kind of Java keystore file called a "JCEKS" keystore, which stores secret keys instead of public/private keys and certificates. A parallel file also tracks the key version number. A tool is provided to regularly update this secret key (and increase the version), which can be pushed to cluster nodes and continually maintain the secrecy of this key. This should be done at least daily to limit the chance for, and damage from, exposure.
...