CMT Cryptosystem

Key Generation:

1. Randomly choose as a decryption key of the base station.

2. For each node, compute an encryption key, Here, is a pseudo-random function (PRF).

Encryption:

1. Given an encryption key and a nonce. A nonce can be forwarded by the base station in a query or it can be automatically generated based on a predefined criteria.

2. Represent a plaintext, as an integer in the range, where is the modulus.

3. Compute the ciphertext,.

4. Set.

5. Forward, as an ID-ciphertext pair.

Decryption:

1. Given a ciphertext, nodes’ identity information ID, and a nonce, generate,.

2. Decrypt the ciphertext,

Ciphertexts Aggregation:

1. Given and

2. Compute an aggregated ciphertext,.

3. Set.