/// <reference types="node" />
import { HexBase64Latin1Encoding } from 'crypto';
export declare class Keygrip {
    private keys;
    private algorithm;
    private encoding;
    constructor(keys: Array<string>, algorithm?: string, encoding?: HexBase64Latin1Encoding);
    sign(data: string): string;
    index(data: string, digest: string): number;
    verify(data: string, digest: string): boolean;
    private _sign(data, key);
    private constantTimeCompare(val1, val2);
}