subgrind

Fast vanity address generator for Substrate / Polkadot / Bittensor. It grinds random BIP39 mnemonics (12 or 24 words) and derives the SS58 account address until one matches a regex.

Addresses match subkey / Polkadot.js exactly — verified against the Substrate dev-phrase test vector (cargo test).

Install

cargo install subgrind

Or grab a prebuilt binary for Linux, macOS, or Windows from the releases page.

Or build from source:

cargo build --release

For maximum throughput on the machine you'll run it on, enable the host CPU's full instruction set:

RUSTFLAGS="-C target-cpu=native" cargo build --release

Don't use target-cpu=native for binaries you redistribute — they may crash with SIGILL on a different/older CPU.

Usage

subgrind <PATTERN> [--prefix 42] [--scheme sr25519|ed25519|ecdsa] [--words 12|24] [--threads N]
subgrind --verify "<mnemonic>" [--scheme ...] [--prefix ...]

• <PATTERN> — a regex matched against the whole address string.
• --prefix — SS58 network prefix (default 42 generic Substrate and Bittensor; 0 Polkadot, 2 Kusama).
• --scheme — sr25519 (default), ed25519, or ecdsa.
• --words — mnemonic length, 12 (default) or 24.
• --threads — worker count (default: all logical cores).
• --verify — re-derive and print the address for an existing mnemonic (cross-check a result).

Examples

subgrind 'SEEK$'          # address ends with SEEK
subgrind '(?i)dot$'       # ends with "dot", case-insensitive
subgrind '[a-z]SEEK$'     # ends with SEEK, preceded by a lowercase letter
subgrind 'KSM$' --prefix 2 --scheme ed25519 --words 24

The program prints progress (attempts/s) to stderr and, on the first match, the result to stdout, then exits.

Notes

• Pattern feasibility. The leading character is fixed by the prefix (prefix 42 → addresses start with 5, Polkadot prefix 0 → 1), so ^... anchors beyond that first char are heavily constrained. Suffix ($) and contains-patterns are the natural fit. Difficulty grows ~×58 per extra fixed base58 character.
• ecdsa matches the 32-byte account address (SS58(blake2_256(pubkey))) — the address wallets and explorers display.
• Security. Keys are generated from a per-thread ChaCha20 CSPRNG seeded from the OS. The found mnemonic is a real secret — store it securely and avoid redirecting it into files that might get committed or synced.
• Speed. The bottleneck is PBKDF2-HMAC-SHA512 (2048 rounds), as mandated by Substrate's key derivation.

License

Licensed under either of Apache License, Version 2.0 or MIT license at your option.