Temporary EID for Secure eSIM Profile Linking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The current GSMA eSIM v3 specification lacks secure mechanisms for linking an eSIM profile to the correct eUICC card, exposing security and privacy risks as the EID is not communicated through the device API, leading to potential profile downloads to unintended cards and inefficient retry processes due to incomplete downloads.
Innovation Solution
A temporary EID (TEID) is generated using a secure hash algorithm and a nonce, which is sent to the mobile operator, allowing the eSIM server to verify the profile download by matching the hash, ensuring the profile is downloaded to the correct eUICC card and reducing redundant identification attempts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If the EID is not communicated through the device API for privacy reasons, then privacy is protected, but the operator cannot link the profile to the correct eUICC card, creating security risks
Solution Approach 1:
A temporary EID (TEID) is introduced as an intermediary between the actual EID and the profile linking process. The TEID is generated by hashing the actual EID with a nonce, allowing the operator to link profiles securely without accessing or exposing the real EID. This mediator enables both privacy protection and reliable profile linking simultaneously.
Solution Approach 2:
Instead of using the actual EID directly, a copy in the form of a hashed version (TEID) is created and used for profile linking. This copy contains sufficient information to identify the correct eUICC card while preventing exposure of the sensitive original EID, thus resolving the contradiction between privacy and security.
2Reliability
If the download procedure requires complete API transaction sessions, then security is maintained, but incomplete downloads require repeated procedures, reducing efficiency
Solution Approach 1:
The TEID is generated and associated with the profile download request in advance, before the actual download begins. This preliminary action allows the system to verify the correctness of the download target without requiring a complete API transaction session, enabling retry without full repetition and improving efficiency while maintaining security.
3Measurement precision
If the EID is exposed during profile download, then the operator can verify the correct card, but security and privacy risks increase
Solution Approach 1:
The identification parameter is transformed from the raw EID to a hashed version (TEID). This parameter change maintains the uniqueness and verifiability needed for accurate card identification while eliminating the security and privacy risks associated with exposing the actual EID. The hashing function ensures that the TEID can be verified against the original EID without revealing the original.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A temporary EID (TEID) is generated based on an indicator of a hash algorithm, a nonce, and a hash generated using the hash algorithm. The hash is generated based on the indicator, nonce, and EID of a mobile device. The TEID is sent to the mobile network operator to identify the mobile device in lieu of using the devices EID. The TEID is stored in a data store and an eSIM profile for the mobile device is associated the TEID. The mobile device sends to an eSIM server the devices EID over a secure communications channel. The eSIM server generates a hash using the indicator and nonce contained in the stored TEID and the EID of the mobile device. The eSIM server verifies that the generated hash matches the hash contained in the stored TEID. If the hash matches, the eSIM server sends subscription credentials for accessing the mobile network.