commerce unique identification number for each item on each transaction What options are they to achieve a unique identification number for each item sold in a commerce store.

I want to have a unique number for each item on each transaction, the number needs to be unique across all transactions.

even if I have 5 of the same line item in an order I should still get 5 unique numbers.

I have a unique id number per item per order but i don't know how to achieve a truly unique id.
Would appreciate any guidance.
prepend your unique id with the order number. Since it's already unique within the order, and presuming an order number is unique, [order-number]-[unique-id] should return a truly unique value with the added benefit of being traceable since the order number would have a searchable or reference-able value.

EDIT:

Further research yielded the module Field default token 

This module enables to use tokens as field default values.


Using this you should be able to create the order-ID combination (or any other combination). To prevent user tinkering, I would also suggest Field Permissions:

The Field Permissions module allows site administrators to set field-level permissions 
to edit, view and create fields on any entity.