I read just the abstract since the entire PDF is too technical to read.

Basically they are saying that you can use the bitcoin hashes derived from blocks to use as a random number generator.

Since the bitcoin hashes are completely random, its a secure way of forming some beacons, like in the example a lottery.

Basically I don't think its really needed. When you nonce a regular SHA512 hash the results will be uniformly random.

Someone even ran a benchmark to prove this.