Object hash settings
At the root folder of the Discovery Tool you can find a file called ObjectHashSettings.xml. This xml file defines which attributes are used to build the Object Hash.
For example:
<!-- VirtualGuestInfo Attributes -->
<VirtualGuestInfo_Name>true</VirtualGuestInfo_Name>
<VirtualGuestInfo_Hostname>true</VirtualGuestInfo_Hostname>
<VirtualGuestInfo_State>false</VirtualGuestInfo_State>
<VirtualGuestInfo_RAM>false</VirtualGuestInfo_RAM>
<VirtualGuestInfo_UUID>true</VirtualGuestInfo_UUID>
<VirtualGuestInfo_ConfigurationFile>false</VirtualGuestInfo_ConfigurationFile>
<VirtualGuestInfo_FirstNICMAC>false</VirtualGuestInfo_FirstNICMAC>
Please note that manually changing these settings will create a new object hash for the "same" object, this will create "duplicates" in Assets when importing that data. Here you can see that for the VirtualGuest object, the attributes Name, Hostname and UUID will be used to build the Object Hash.
If you make changes to these settings, you may have to remove duplicate or unwanted information.
Hash generation
In our Best practices and FAQs article which covers best practices for using Assets Discovery, you can see that the algorithm used to generate the hash is MD5.