the first production zk-SNARK system (2016): shielded transactions prove validity of hidden values against a commitment tree, spending via nullifiers — the grammar every private ledger now speaks, bbg included. its proof systems trace the whole history of the art: Sprout (BCTV14, trusted setup) → Sapling (Groth16) → Orchard (Halo 2, no trusted setup) → Tachyon, the scaling project aiming oblivious sync and a shielded pool fast enough to be the default at whole-chain scale
the lesson: cryptography this strong still lost to economics — most ZEC lived transparent because shielding was opt-in and wallets made it work. default matters more than elegance
privacy · privacy/monero · bbg