English term (edited): Supply Group Code Vending Key

clé de cryptage au point de vente associée au fournisseur d'énergie [à son "code fournisseur"]

sorry - couldn't make it shorter.

to make it more digestible:

Once new security modules have been initialised by the KMC they must be loaded with one or more Supply Group Code Vending Keys.
=
.... être charges avec une / des clé(s) (de cryptage) associée(s) a un ou plusieurs "code(s) fournisseur" / fournisseur(s) d'énergie


Once new security modules have been initialised by the KMC they must be loaded with one or more Supply Group Code Vending Keys.
....
Your SGC key file which is unique to your security module will be delivered to you by the KMC separately from the actual security module. [THAT definitely sounds like handling an encryption key!]

http://www.sts.org.za/Services/SupplierGroupCode.aspx


Supply Group Code Vending Key has two parts:

"Supply Group Code" and "Vending Key"
so it's
the "Vending [cryptographic] Key" allocated / associated with the "Supply Group Code", i.e. with the energy provider identified by its "Supply Group Code"

IOW this "Supply Group Code Vending Key" will be used to encrypt every token sold by that supplier.

Now, on the same site is the application for obtaining the "Supply Group Code":


APPLICATION FOR SUPPLY GROUP CODE (SGC)
....
http://www.sts.org.za/Portals/27/Documents/Services/Applicat...

It's basically just a simple registration form for a company to register as energy supplier (pour obtenir un "code fournisseur")

Obviously what will be stored in the system has to be encrypted - thus the need for a corresponding [cryptographic] Key (generated by STS - see "generation of keys" in the other questions) to be used at the point of sale by the Vending machine to identity the energy supplier selling the token.