SUPI / SUCI Analyzer
Paste a SUCI NAI string (suci-0-MCC-MNC-RI-Scheme-HNPKI-SchemeOutput), a raw hex SUCI payload (per TS 24.501 §9.11.3.4), or a plain IMSI — and see every field decoded instantly.
- Protection Scheme = 0 (null) — the SUPI / IMSI portion is sent in the clear.
- Routing Indicator = 0 means no NSSAI-based AUSF routing (default).
- Scheme Output in the null case is the raw MSIN.
Field reference
| Field | Values | Meaning |
|---|---|---|
| SUPI Type | 0 / 1 | 0 = IMSI, 1 = NAI (network-specific) |
| MCC | 3 digits | Mobile Country Code (e.g. 208 = France) |
| MNC | 2–3 digits | Mobile Network Code (operator within country) |
| Routing Ind | 0 – 999 | Steers the SUCI to the right AUSF/UDM; 0 = default |
| Prot. Scheme | 0 / 1 / 2 | 0 = null, 1 = ECIES Profile A, 2 = ECIES Profile B |
| HNPKI | 0 – 255 | Home Network Public Key Identifier (0 for null scheme) |
| Scheme Output | Hex / digits | Null: raw MSIN. ECIES: ephemeral PK + ciphertext + MAC |
About SUPI, SUCI and the privacy leap from 4G
In 4G, the UE sent its IMSI in the clear whenever the network couldn't map a GUTI — enabling well-known IMSI-catcher attacks. 5G fixes this with the SUbscription Permanent Identifier (SUPI) and its concealed form, the SUbscription Concealed Identifier (SUCI). The SUCI is built by the UE, encrypting the MSIN portion of the SUPI with the Home Network's public key using ECIES (Profile A or B, per TS 33.501 §6.12). The MCC, MNC and Routing Indicator remain in the clear so the serving network can route the authentication request to the right AUSF/UDM, but the subscriber identity itself is protected.
This tool decomposes either the NAI string representation (used in SBI / JSON bodies) or the raw hex payload carried inside the 5GS Mobile Identity IE (TS 24.501 §9.11.3.4), and calls out the classic misconfiguration: deploying a profile with Protection Scheme = 0, which gives you exactly zero privacy over 4G.
References
- 3GPP TS 23.003 — Numbering, addressing and identification
- 3GPP TS 24.501 §9.11.3.4 — 5GS Mobile Identity IE (SUCI format)
- 3GPP TS 33.501 §6.12 — Privacy of subscription identifier
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