Anonymous Communication via Anonymous Identity-Based Encryption and Its Application in IoT

Algorithm 2

Anonymous communication protocol.

Encryption. If the sender just wants to disclose the message anonymously rather than anyone knows where is message

from even the recipient, he computes the ciphertext ; If the sender wants the

recipient to know about its identity, the signature should be attached with the message , compute the ciphertext

. The Encryption operation should done in specific time .

Upload. All the users uploads their ciphertexts to the bulletin board at the specific time . Each user’s ciphertexts are

stored in the bulletin board after this operation.

Download. Each involved users are required to download all the ciphertexts which stored in the bulletin board, each

user does the Download operation at the specific time .

Decryption. The user decrypts the ciphertexts which obtained from the bulletin board in Download operation, one by

one through the private key in specific time . The plaintext is computed as . If there is a

signature attached with the message , then the user can get .