Realizing Flexible Broadcast Encryption: How to Broadcast to a Public-Key Directory
Rachit Mohan Garg, George Lu, Brent R. Waters, David J. Wu · 2023
Suppose a user wants to broadcast an encrypted message to K recipients. With public-key encryption, the sender would construct K different ciphertexts, one for each recipient. The size of the broadcasted message then scales linearly with K. A natural question is whether the sender can encrypt the message with a ciphertext whose size scales \em sublinearly with the number of recipients.