/** Generate a cryptographically strong pseudo-random data @param size - Size of the string @returns A cryptographically strong pseudo-random data */ export function randomString(size: number): string; /** Generate a cryptographically strong pseudo-random alphanumeric data @param size - Size of the string @returns A cryptographically strong pseudo-random alphanumeric data */ export function randomAlphanumString(size: number): string; /** Return a random string of digits @param size - Size of the digits @returns A random string of digits */ export function randomDigits(size: number): string; /** Generate a buffer of random bits @param bits - Number of bits @returns A buffer of random bits */ export function randomBits(bits: number): Buffer; /** Generate a buffer of random bits @param a - Data to compare @param b - Data to compare @returns A boolean comparing a and b */ export function fixedTimeComparison(a: string | Array, b: string | Array): boolean;