NU5, the first major upgrade since November 2020, includes the launch of the Orchard shielded payment protocol, utilizing the Halo proving system to remove reliance on complex setup ceremonies. The efficiencies built into this upgrade make possible — for the first time ever — private, trustless digital cash payments on mobile phones. Halo also paves the way for increased interoperability by providing a system that could unlock private cross-chain proofs at scale.