Simple collection of data secures account (6)
I believe the answer is:
facile
'simple' is the definition.
(thesaurus)
'collection of data secures account' is the wordplay.
'collection of data' becomes 'file' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'secures' indicates putting letters inside.
'account' becomes 'ac' (abbreviation for account).
'file' enclosing 'ac' is 'FACILE'.
Can you help me to learn more?
(Other definitions for facile that I've seen before include "Easy to accomplish" , "A piece of cake" , "Effortless, easy" , "Glib or fluent (6)" , "Over-simple, superficial" .)