We study two closely related primitives: Broadcast Encryption and Key Predistribution Schemes (KPS). Broadcast Encryption allows a broadcaster to broadcast an encrypted message so that only a designated group of users can decrypt it. KPS allows a designated group of users to establish a common key non-interactively. We discover a generic method to construct efficient broadcast encryption scheme...

According to the broadcast encryption scheme with wide applications in the real world without considering its security and efficiency in the model simultaneously an “unbounded”, Key-Policy Attribute-Based Broadcast Encryption scheme(KP-ABBE) was proposed by combining with waters dual system encryption, attribute-based encryption and broadcast encryption system. Based on the standard model, the ...

We present new techniques for achieving adaptive security in broadcast encryption systems. Previous work on fully collusion resistant broadcast encryption with short ciphertexts was limited to considering only static security. First, we present a new definition of security that we call semi-static security and show a generic “two-key” transformation from semi-statically secure systems to adapti...

We present new techniques for achieving adaptive security in broadcast encryption systems. Previous work on fully collusion resistant broadcast encryption systems with very short ciphertexts was limited to considering only static security. First, we present a new definition of security that we call semi-static security and show a generic “two-key” transformation from semi-statically secure syst...