Hello!
For the icon in the entry
#18 , the center object represents a keyhole with the top in a form of a heart. In the background it's a a key with the handle in form of a ''C'' intial from word ''cracking'' or ''codes''.
In entry #24 the ideea around the icon is : the left part of the heart represents the code (ilustrated in lines) combined with the right part representing the other half that have the key to it.
I will make the modifications that you've required right now.
King regards,
Ilie.