Why Subscription Management is required
In order to register a SIM-module in operator’s network, it’s necessary to download operator’s mobile profile onto SIM-module. Mobile profile is at least an IMSI and a set of secret keys for authentication.
Symmetric key exchange, organized within the "Request" smart-contracts from first transaction is very useful for such kinds of interactions in BT, allowing parties organize fast and secure communication channels, saving time and resources spent for extra challenge - response handshakes between operators' equipment.
It allows secure downloading of Assignee mobile profile on the end-user's SIM-module or exchanging any kind of secret data between participants. The necessary symmetric key can be obtained by both parties from "Offer" and "Request" transactions.
Downloading of mobile profile is performed in accordance with one of the standards for the telecom industry described below.
Built-in OTA platform
BTClient has built-in OTA platform developed in accordance with the "GSM 03.48 "Security Mechanism for the SIM" standard. It means that the platform provides high-secure preparation of binary SMS with credential data using unique OTA keysets assigned to each SIM-card by SIM vendor:
- Mobile profile preparation is based on OTA Template defined in the "BTCient Web Account". The template contains following mandatory instructions called "APDU commands":
* imsi * ki
- 2 Additional settings could be defined by Offer Assignee who owns the mobile profile:
- 3 Prepared list of APDU commands is encrypted by OTA keys ("KID" and "KIc") as described in "GSM 03.48 "Security Mechanism for the SIM" standard
- 4 Encrypted APDU commands are splitted into concatenated SMS
Usage of own OTA platform
It’s important that these solutions should comply the telecom standards above.