This disclosure provides techniques for securely communicating user equipment (UE) specific information from a UE to a network-side device. In particular, the UE may either encrypt the UE specific information using an encryption key to form an encrypted portion, where the UE specific information includes subscriber identity information and the encryption key is calculated in accordance with a public key of a home network of the UE. The UE generates a message authentication code (MAC) signature based on the encrypted portion and a first integrity key, where the first integrity key is calculated in accordance with the public key of the home network. The UE sends, to a network-side device, a request message including the encrypted portion, the MAC signature and a network identifier of the home network.