Libra is a zero-knowledge proof protocol that achieves extremely fast prover time and succinct proof size and verification time. Not only does it have good complexity in terms of asymptotics, but also its actual running time is well within the bounds of enabling realistic applications. It can be applied in areas such as blockchain technology and privacy-preserving smart contracts. It is currently being implemented by Oasis Labs. This blog post is based on a paper authored by Tiancheng Xie, Jiaheng Zhang, Yupeng Zhang, Charalampos Papamanthou and Dawn Song.