A new cryptography scheme for selective broadcasting

We propose a new cryptography scheme that allows for selective broadcasting and precludes collusion between malicious nodes located inside the intended broadcast group as well as outside of the group. In our scheme, the decryption key for each node is customized and embeds personal information inherent to each node. Compared to the Attribute-based encryption approach (ABE) where the nodes satisfying a predefined set of attributes can decrypt a message, our scheme allows for the customization of each node's decryption key based on private information about a node. This approach discourages users to openly reveal their private information and disclose their private keys. Our scheme can achieve a constant ciphertext size regardless of the number of users in the broadcast group. We also present the storage overhead consideration and discuss some potential applications of this cryptography scheme.