5G key generation / ECC key generation and SUCI calculation

A method for generating, in a universal integrated circuit card, UICC, a 5G subscriber concealed identifier, SUCI, for a 5G mobile communication network, the method comprising the steps executed in a processing entity comprised in the UICC:

• (1) generation of a public/private key pair or an Elliptic Curve Cryptography, ECC, public/private key pair;
• (2) Diffie Hellman, DH, or Elliptic Curve Diffie Hellman, ECDH, derivation of an Ephemeral shared key from the public/private key pair or ECC public/private key pair;
• (3) derivation of a symmetric encryption key from the Ephemeral shared key;
• (4) concealment of at least a part of a subscriber permanent identifier, SUPI, with the generated symmetric key to compute the SUCI,
• wherein
• steps (1), (2) being triggered by occurrence of a deterministic event at the UICC, the deterministic event occurring independently from receipt of a GET IDENTITY and/or & GET STATUS command at the UICC, and further comprising:
• storing the generated public/private key pair or ECC public/private key pair and Ephemeral shared key to a key memory provided in the UICC;
• and
• steps (3), (4) being triggered by receipt of the GET IDENTITY command at the UICC subsequent to steps (1), (2).