Demonstration of "Collusion Resistant Broadcast Encryption With Short Ciphertexts and Private Keys" BGW05

install

this code depends on mcl-wasm and other modules. Install them with:

npm i

test

node src/bgw.js

Demonstrate the special case:

• setup a system of n users, run time and public key size linear with n (64 bytes, 2.4 ms per user.)
• create a random set S of users that will be allowed to decrypt.
• create a random encryption key K and encrypt it. Run time linear with |S| (12usec per user)
• select ntrial random users and check that only users in S can decrypt and retrieve K. Run time linear with |S| (4usec per user)

The general construction is achieved by splitting the users into shards of size n and splitting S accordingly. You can use the same public key in each shard except for a different gammain each shard. So now all sizes are proportional to the shard size.