export declare namespace mnemonic {
    /**
     * generate BIP39 mnemonic words
     * @param rng the optional random number generator, which generates 16~32 (step 4) random bytes.
     * Every 4 bytes produce 3 words.
     */
    function generate(rng?: () => Buffer): string[];
    /**
     * check if the given mnemonic words have valid checksum
     * @param words mnemonic words
     */
    function validate(words: string[]): boolean;
    /**
     * derive private key at index 0 from mnemonic words according to BIP32.
     * the derivation path is defined at https://github.com/satoshilabs/slips/blob/master/slip-0044.md
     */
    function derivePrivateKey(words: string[]): Buffer;
}