import { arrayify } from 'ethers/utils';
export declare function toHex(message: string): string;
declare const _default: {
    arrayify: typeof arrayify;
    toHex: typeof toHex;
};
export default _default;
export declare type HexString = string;
export declare function isHexString(value: any): value is HexString;
/**
 * Check if an URI is secured or not according to SDK configuration.
 * @param value
 * @return True if the uri is secured.
 */
export declare function isValidURI(value: any): boolean;
/**
 * Check if an URI is secured or not according to SDK configuration.
 * @param value
 * @return true if the URI is secure or unsecured endpoints are allowed.
 * @throws UnsecuredURIError if the URI is not secure.
 */
export declare function guardSecuredURI(value: any): boolean;