given a seed value "iv" (optional), returns a deterministic string of pseudo-random hex values of length "chars"

sha3stream.js

function stream(chars, iv){ // requires https://github.com/emn178/js-sha3/
	var buff="", i=0;
	iv= sha3_512(iv || (Date.now() / (performance.now()*1000)).toString(36) + (chars/Math.random()));
	while(buff.length < chars) buff+= iv = sha3_256(++i + iv);
   return buff.slice(0, chars);
}

//ex:
// stream(500, "this is not a great iv");