Versions: Artifactory 7.X
It hopefully goes without saying that this file is very important, and it should not be lost. If the master.key is lost, the services that rely on the master.key won't be able to start. That being said, recovery is still possible!
The master.key is a secret key used to encrypt key tables in the database, it was introduced in Artifactory 5.7. By default, this file is automatically generated during the first start of the application.
One of the main usages of the master.key is to be a key step when setting up a High Availability cluster of Artifactory. The master.key is also used to encrypt all sorts of information saved in the database, in addition to passwords saved on the file system (Ex: $JFROG_HOME/etc/system.yaml). Moreover, all sensitive data managed by Access are also encrypted using the master.key, such as users’ passwords, API keys, etc.
Recovering from a lost master.key is tricky and requires connecting to the database. It’s a different procedure between Artifactory version 6.x and 7.x.