X11

X11 is a chained sequence of 11 distinct hash functions (Blake, BMW, Groestl, JH, Keccak, Skein, Luffa, CubeHash, SHAvite, SIMD, ECHO) executed in serial order. The algorithm was designed by Evan Duffield in 2014 for what was then XCoin (later Darkcoin, now Dash). The design goal was twofold: ASIC resistance through hash diversity (you’d need silicon implementations of all 11 functions), and lower energy consumption per hash (since most hashes wouldn’t need exhaustive computation when intermediate rounds dropped below the target).ASIC implementations ultimately did emerge — Bitmain’s D-series, Goldshell’s XT-series — but X11 hardware retained one notable property: it’s energy-efficient per dollar of revenue at most points in the cycle, particularly compared to SHA-256 hardware with similar capex.Dash remains the primary X11 chain. Network economics are stable, with InstantSend / PrivateSend features giving DASH real utility distinct from Bitcoin.