Ruby on Rails

Hello I'm quite new to the rails 4 and I've not dealt with this kind of nested security warnings, I basically have a model (receipt), with has many items relation. When I save a receipt, I want to have an options to save many items as well from the same form, I ll skip the ui part and get back to the back end, this is how my params look like, when I print params in the create action :

{"utf8"=>"✓",

 "authenticity_token"=>"0LPWkN5uG+yHrVt99f4bBN+al0FCARNhtV91NysV0TM=",

 "receipt"=>

  {"store_id"=>"2",

   "purchase_date"=>"05/05/2015",

   "items_attributes"=>

    {"1432495749993"=>{"item"=>{"name"=>"ssd", "amount"=>"22", "unit_id"=>"2", "quantity"=>"1", "person_id"=>"2", "project_id"=>""}},

     "1432495820856"=>{"item"=>{"name"=>"ds", "amount"=>"22", "unit_id"=>"3", "quantity"=>"1", "person_id"=>"2", "project_id"=>""}}}},

 "action"=>"create",

 "controller"=>"receipts"}

I've tried following and more but none of it didn't work :

params.require(:receipt).permit(:store_id, :purchase_date, :items_attributes)

params.require(:receipt).permit(:store_id, :purchase_date, items_attributes: {'1432495749993' => {'item' => [:name]}})

params.require(:receipt).permit(:store_id, :purchase_date, items_attributes: {'1432495749993' => {'item' => [:name]}}).permit!

params.require(:receipt).permit(:store_id, :purchase_date, items_attributes: {'1432495749993' => {'item' => [:id, :name, :amount, :unit_id, :quantity, :person_id, :project_id]}})

And my nested params don't show, this is the best result I got :

{"store_id"=>"2", "purchase_date"=>"05/05/2015", "items_attributes"=>{"1432495749993"=>{}=>{}}}

I'm getting to the point when I don't know what to need to ask somebody for help, what am I doing wrong here?