Observed arrival · 2026-09-03
COBRA: Offline Bitcoin Address Derivation
An open-source toolkit for generating cryptographic randomness and deriving Bitcoin mainnet addresses locally in a browser or Python environment.
Field notes
The browser interface exposes four randomness formats—integers, hexadecimal strings, raw bytes, and UUID v4—before feeding a selected 32-byte value into the address workflow. The visible derivation sequence names secp256k1, SHA-256, RIPEMD-160, double-SHA-256 checksum creation, and Base58Check encoding. COBRA also provides a recovery-kit download, an opt-in public-address explorer, and links to Python and CLI-oriented materials; the CLI and Offline Lab are explicitly described as experimental.
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