Comprehensive technical knowledge base covering 12 GSMA eSIM specifications. 84+ articles on Remote SIM Provisioning — SGP.02, SGP.22, SGP.32, SGP.41, SGP.29, SGP.23, SGP.25, SGP.26 and more.
You walk up to a hotel front desk. “I have a reservation,” you say. The clerk asks: “What’s your name?” You tell them, they look it up, and: yes! : a room is waiting. Then they ask for your ID to prove you really are that person before handing over the key.
That’s exactly how the EID works in eSIM protocols: showing your ID card to prove who you are. The EID is how eSIM chips announce themselves, get matched to waiting profiles, and prove their identity before receiving secret keys.
The EID appears in at least four major operations across the eSIM world:
The SM-DS (Subscription Manager Discovery Service) is like a post office for eSIM profiles. Here’s how it works:
1. Carrier prepares a profile for your chip → registers it with SM-DS using your EID
2. Your device asks SM-DS: "Anything waiting for EID 12345...?"
3. SM-DS looks up the EID: "Yes! A profile from carrier XYZ is ready!"
4. Your device goes to download it
Without the EID, the post office wouldn’t know which pigeonhole belongs to which chip!
The ES11 interface is how the helper app on your device (the LPA) checks for waiting profiles:
LPA → SM-DS: "Any pending events for EID 12345...00133?"
SM-DS → LPA: "Yes → download from dp.example.com"
The EID is the primary lookup key in every ES11 query. The helper app polls periodically (or when you open the eSIM settings), always using the EID as the identifier.
This is where the EID becomes a security anchor. Before any profile is delivered, the chip and the Key Maker do a two-way identity check:
| Step | What Happens |
|---|---|
| Key Maker → Chip | “I have a key for EID 12345… : is that you?” |
| Chip verifies | “Is this Key Maker’s certificate valid? Is this key really for me?” |
| Chip → Key Maker | “Yes, I am EID 12345… Here’s my cryptographic proof!” |
| Key Maker verifies | “Does the EID match? Is the certificate valid? Is the signature correct?” |
| Key Maker → Chip | “Confirmed! Here’s your encrypted key package!” |
The EID is the name on both sides of this handshake. It’s how the chip claims its identity, and how the Key Maker confirms it’s talking to the right chip.
Sometimes a profile isn’t ready immediately. The Key Maker can register an event:
Key Maker → SM-DS: "Register: when EID 12345... checks in,
tell them a profile is ready at dp.example.com"
The next time that chip polls the SM-DS, the waiting event appears. The EID is the link between the event and the chip.
The EID is universal: it works across all major eSIM specifications:
| Specification | How EID Is Used |
|---|---|
| SGP.22 (Consumer) | ES8+ downloads, ES11 polling, SM-DS discovery: your phone’s eSIM |
| SGP.32 (IoT) | Same pattern, but for smart sensors, meters, and trackers |
| SGP.02 (M2M) | Profile download and management for machine-to-machine devices |
Same EID format, same rules, different device types. That’s the beauty of a universal identifier!
SGP.29 Principle EID.P02 demands global EID uniqueness. Here’s what would happen if two chips shared the same EID:
| Scenario | Disaster |
|---|---|
| Wrong profile delivery | Chip B receives a profile meant for Chip A: potentially giving an attacker access to someone else’s mobile plan |
| SM-DS confusion | The Discovery Service can’t tell which chip should get which profile |
| Authentication failure | Cryptographic handshakes fail because the Key Maker can’t distinguish between two chips claiming the same identity |
Global uniqueness is not optional: it’s the foundation everything else rests on!
When your eSIM helper app polls the SM-DS for pending profiles, it does so using your chip’s real EID: but the connection is encrypted, and the SM-DS requires authentication. Knowing someone’s EID alone isn’t enough to steal their profiles. The EID is a claim of identity, but the cryptographic proof (the chip’s private key) is what actually proves it!
Kid-friendly version of GSMA SGP.29 v1.1: EID in RSP Protocols, Section 6