The generate password dialog appears when you click Generate... on the Package attributes panes. It allows you to specify the effective key length for the password and thereby its strength.
Dialog fields and options
The dialog contains some introductory text and one field.
|Effective key length for password
Enter the desired effective key length for the password that InstallMate generates for your installer. Allowable key lengths are 1-128 bits; due to the way the password is generated, the actual password key length may be slightly longer.
Passwords are generated as cryptographically secure random numbers of the length that you specify, rounded up to a whole number of bytes. They are then encoded using the digits 2-9 and letters A-Z (minus I and O), which acts as a base-32 encoding. Therefore, the actual number of password characters is approximately key_length / 5.