Zerocash early versions had a bottleneck issue: generating a private transaction takes nearly a minute, which is even more pronounced on average computers, and it also consumes several GB of memory. This directly results in very few people actually using the privacy features, especially on low-end devices like smartphones.

After the Sapling upgrade, Zcash made significant optimizations. They introduced the BLS12-381 curve, reducing generation time to just a few seconds, and memory usage to just over 40MB. This made it truly possible to run private transactions on mobile devices.

However, to achieve the strongest anonymity and top-tier performance, the cost is complex cryptographic structures, trusted setup, and high computational complexity—all of which are unavoidable.

Recently, Electric Coin Company developed the Halo 2 verification system, with a new protocol called Orchard. Compared to Sapling, which uses different verification systems, Orchard’s key advantage is that it requires no trusted setup process. Testnet benchmarks show that while performance is slightly lower than zkSNARKs based on Sapling, it remains highly competitive.

But there’s a catch: both Halo 2 and Orchard use the BOSL license, and before the grace period ends, outsiders cannot access Halo 2’s code. Moreover, although the earliest Halo verification system has an academic preprint published, Halo 2 currently lacks a publicly available academic paper to support it.

Auditing firm QEDIT pointed out a more pressing issue: Orchard does not have the complete security proof and summary like Sapling does. They also emphasized that such a complex system and implementation are a nightmare for audits, and many components of the protocol are still poorly documented. Therefore, while Orchard has a promising outlook, its architecture is highly complex and requires more review and understanding. Coupled with strict licensing restrictions and insufficient documentation, anyone using Orchard or Halo 2 ultimately has to trust Electric Coin Company’s security guarantees.